Re: [Elecraft] Elecraft Kit Assembly
And a whole $2.00! That's pretty much what the Heathkit one looks like, only red. 73, Scott K9MA On 12/2/2020 3:56 PM, Harry Yingst wrote: Looks like Jenson Tools sells them Look Here https://www.jensentools.com/menda-35120-four-way-nut-starter/p/758ie351 On Wednesday, December 2, 2020, 03:37:55 PM EST, K9MA wrote: When assembling the KAT500 kit yesterday, I found it frustrating trying to get the nuts started on the connector screws. Then I remembered assembling Heathkits, like 50 years ago. Heathkit provided a little plastic tube thingy for starting hex nuts. (I'm sure some of you other OF's remember them. They were red.) I looked in the toolbox, and there were two of them! (They're still red.) Given all the hex nuts in the KAT500 kit, if I hadn't already had them, I'd have been glad to pay an extra 10 cents or so if one were included with the kit. 73, Scott K9MA -- Scott K9MA k...@sdellington.us <mailto:k...@sdellington.us> __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net <mailto:Elecraft@mailman.qth.net> This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to hlyin...@yahoo.com <mailto:hlyin...@yahoo.com> -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Elecraft Kit Assembly
When assembling the KAT500 kit yesterday, I found it frustrating trying to get the nuts started on the connector screws. Then I remembered assembling Heathkits, like 50 years ago. Heathkit provided a little plastic tube thingy for starting hex nuts. (I'm sure some of you other OF's remember them. They were red.) I looked in the toolbox, and there were two of them! (They're still red.) Given all the hex nuts in the KAT500 kit, if I hadn't already had them, I'd have been glad to pay an extra 10 cents or so if one were included with the kit. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA500 Remote Power Switch
A friend in Europe is setting up a K3 and KPA500 for remote operation. Does anyone know of a suitable 240 V EU remote power switch? 73, Scott K9MA -- Scott Ellington --- via iPad __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 Schematics
A while ago, someone suggested that Elecraft would provide the KPA1500 and other unreleased schematics to customers. That is not the case: "HI Scott, Thanks for contacting Elecraft. While the released schematics are posted on the Elecraft website, they do not yet include the KPA1500." 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 SWR Tolerance
I've long been aware that my KPA1500 would not run at full power (1.5 kW) unless the SWR was very low. (This is SWR at the input to the ATU, if used.) The current ATU firmware does a pretty good job of keeping the SWR below about 1.3:1, which usually is low enough. In any case, I just ran a simple test on 160, where I have an antenna I can easily tune to 1:1, or deliberately higher. The ATU was engaged, but it's settings were not changed during the test. The SWR indicated was that at the ATU input (amplifier output). I found that the output power remained nearly constant up to 1.4:1, but the current increased from 58 to 62 A. (This with no adjustment of the K3 power, though the indicated input power varied slightly.) At 1.5:1, the current exceeded 65 A and the amplifier faulted. By reducing drive, I was able to run it at 1.4 kW output and 60 A. The above is typical of my experience on other bands, etc. The effect of SWR on the amplifier, of course, depends on the actual impedance at the amplifier, so in some cases it may be more or less sensitive to SWR. Do others see similar effects? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] RFI issues
It's really important to make sure you're listening to the right source. One way to do that is to listen to the audio from your home receiver (AM mode, AGC off, RF gain backed down to avoid overload) while you are searching. There will be a pattern of fluctuations. When they match, you have the right source. You can relay the home receiver by phone, VHF/UHF, etc. 73, Scott K9MA On 2/20/2020 11:48, Phil Hystad via Elecraft wrote: I once had a noise issue and I used my KX3 roving about the neighborhood to find it. Actually, I found a number of loud noise sources doing that as I moved around. It seems that if the noise level is fairly constant as you move around the area but will within the same general distance from the TV/FM station antennas you could isolate the source as those antennas or something else. 73, phil, K7PEH On Feb 20, 2020, at 9:42 AM, Jim Brown wrote: On 2/18/2020 4:38 PM, Andreas Wachter via Elecraft wrote: Yes, I did run the K3 off of a battery and pulled the main AC breaker. Didn’t make any difference. Thus my suspicion that the RFI is related to the 208 kW ERP TV station (and/or 63 kW EPR FM station) which are within 1.6 miles and in direct line of sight. Do you have neighbors? Did you pull their breakers at the same time? Do you have a UPS? They continue to run without power, so both they and any connected equipment can create noise. Did you take the time to study the link I posted? 73, Jim K9YC __ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRO - KPA500 Failure
That's very high efficiency for a solid-state amplifier. Are they operating in class C? Are there any IMD specs at those output levels? 73, Scott K9MA On 2/11/2020 03:18, Edward R Cole wrote: I checked the operating specs on two of my QRO amps. Not a KPA500. 2m-1500w PA using a MRF1K50 in class AB: 945w 1398w dc 67% eff 453w disp 1511w 1888w dc 80% eff 377w disp 2m-1200w PA using a MRFE6VP61K25H in class AB: 566w 1200w dc 47% eff 634w disp 1133w 1542w dc 73% eff 409w disp less heat dissipated when running full power RF ouput. Both are W6PQL amps. 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: dubus...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRO - KPA500 Failure
Several others have posted test data for the KPA500 here recently. As I recall, it shows that dissipated power is fairly constant from about 50 percent to full output, at about 500 W, dropping a bit at lower power. If it were an ideal class B amplifier, which no solid state RF amplifier even approaches, the efficiency at full output would be 78.5 percent. It would then dissipate only 141 W at full output, and maximum dissipation would be at some lower output power level. This is probably what folks are thinking of when they assume maximum dissipation occurs at less than full output. REAL RF amplifiers don't behave that way, as the test results show. https://en.wikipedia.org/wiki/Power_amplifier_classes#Class_B 73, Scott K9MA On 2/10/2020 09:23, Doug Turnbull wrote: Hello Andy, I do not have the numbers and also would like them. I understand that efficiency decreases as one derates from the maximum of 1500W output. It surprises me that the power dissipated would peak at half power output or 750 Watts. This may be so.If so then almost certainly the Mean Time Between Failures or MTBF is worsened. I am not in a position to determine any of this but maybe some guidance from Elecraft itself would be helpful for both KPA 500 and 1500. 73 Doug EI2CN From: Andy Durbin Sent: Monday 10 February 2020 14:04 To: Doug Turnbull ; elecraft@mailman.qth.net Subject: Re: [Elecraft] QRO - KPA500 Failure Doug, "I would like to know if running 2/3, 1/2 or even 1/4 maximum power output increases reliability and MTBF." I have no experience of amplifier design but I would expect reliability of the finals to depend on temperature. Finals temperature will depend on the power dissipated in the finals (PA dissipation) and the effectiveness of the cooling design. To understands finals dissipation one would need to produce one's own test data or rely on the work of others. My test data for the KPA500 shows PA dissipation peaks at about half power output. So far no one has disputed the validity of my test data. It is my understanding that running an amplifier at reduced power only reduces PA dissipation if the finals voltage is adjusted give a good load match for that reduced power condition. The KPA500 has no provision for adjusting PA voltage for the reduced power case. For reduced power the PA voltage is actually higher than for full power because the high voltage supply is not regulated. As I said, I have no experience in amplifier design and would appreciate comments from those who do. 73, Andy, k3wyc __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] FW: Testing IMD3 (dB) K3S (#10490)
On 2/8/2020 21:45, Joe Subich, W4TV wrote: Note: this is into a *non reactive* 50 Ohm load. If the load differs from 50 ± j0 Ohms, IMD is likely to be worse due to the mismatched load. Joe makes a very good point. Even with 14.5 V and a perfect 50 Ohm load, 12 V PA's have marginal IMD at 100 W. If there is a moderate mismatch, like 1.2:1, it can be much worse. Given that ATU's don't consistently get the SWR below that, IMD is often likely to be pretty bad. (It would be very interesting to see some test results with 1.2:1 at various phase angles.) Fortunately, a lot of amplifiers, including all the solid state ones, require much less drive power. Unfortunately, some of the solid state amplifiers are also likely to generate more IMD if they aren't perfectly matched. (And they're not that great when they are matched.) Reducing power a bit should help. Running an amplifier capable of 2.5 kW at 1.5 kW would probably keep the IMD pretty low, even with a moderate mismatch. It would also be very expensive. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] FW: Testing IMD3 (dB) K3S (#10490)
Supply voltage, under load, at the radio? 73, Scott K9MA On 2/8/2020 16:14, Conrad PA5Y wrote: I have some comments. My TX IMD is even worse and I was not very happy with the advice I got from Elecraft. I was advised to use the radio in test mode and use an external amplifier. Periodically I have a complain about it. My 10W PA is also poor even after the FW upgrade that allows additional attenuation to the drive. There are a few of us who discuss this off reflector and it is by no means uncommon. On a more positive note I must say that the transverter port output is exceptionally good. Its really impressive. As for the PA IMD, good luck, you will need it. Regards Conrad PA5Y -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of hb9...@hispeed.ch Sent: 08 February 2020 01:00 To: elecraft@mailman.qth.net Subject: [Elecraft] FW: Testing IMD3 (dB) K3S (#10490) Subject: Testing IMD3 (dB) K3S (#10490) Hi Can anyone roughly confirm IMD3 K3S ? 10W/100W module recently exchanged under Elecraft swap program Rev A (2019). Testing: Using K3S internal 2 Tone and -60dB power attenuator (50Ohms) , HP 8591E Spectrum Analyzer (Span 10kHz) 72W (Tune, LP100A)out into 50Ohm: IMD3 (#10490) -->about on 160m 34 dB, 80m 32dB, 40m 34 dB, 20m 26dB, 17m 30 dB, 10m 30dB, 6m 26dB Yes, all was aligned (TX Gain test) and showing 100 to 90W full power on all bands. The driving signal to 10W PA (one tone) looked better than 50dBc. I think these IMD3 values are not very impressive. A power amp. would typically further degrade the overall results. So K3S is rather good for CW but not really good as SSB preference? (I have now also a FTDX101MP) Comparing with K3 (#7848) upgraded myself to "S", but still maintaining the old 10/100W modules. 80m and 20m were better by about 6dB!? The two tones (IMD3 Test Tones) however were in both cases never absolutely identical in amplitude (ca. +/-1dB) on the analyzer. Any comments? Tnx, Cu, vy 73 de Andy HB9CVQ, DK2VQ, AK4IG <https://www.qrz.com/db/HB9CVQ> https://www.qrz.com/db/HB9CVQ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRO - KPA500 Failure
Basically, based on Bob's measurements, the power dissipated is fairly independent of drive level. So, running at reduced power really isn't stressing anything any more that full output. (Unlike an "ideal" class B amplifier.) 73, Scott K9MA On 2/6/2020 16:06, Bob McGraw K4TAX wrote: I've never seen much if any advantage in running a linear below its rated output. I know the regulation state never run more power than needed for adequate communications or terms like that. The difference between 500 watts and 100 watts is 6.9 dB or about 1 S unit. In fact, most all of the time, running at less than rated output is less efficient. It saves nothing. Same for tube amps where I hear hams say they are running at reduced power to "save the tubes". Nope, not the case. (RF output / DC input) * 100 = % efficiency DC input watts = DC volts x DC amps Do the math and you'll see what I mean. A quick run of the numbers with my KPA500 into a dummy load. Output measured with a Bird 43. DC values taken from the KPA500 display 450 W out, 819 W input, 64 volts @ 12.8 amps for 55% efficiency Drive pwr = 16.5W 14.3 dB gain 819 - 450 = 369 watts = heating factor = 0.88 210 W out, 576 W input, 67 volts @ 8.6 amps for 37% efficiency Drive pwr = 7.0 W 14.7 dB gain 576 - 210 = 366 watts = heating factor = 1.74 100 W out, 393 W input, 69 volts @ 5.7 amps for 25% efficiency Drive pwr = 3.2 W 14.9 dB gain 393 - 100 = 293 watts = heating factor = 2.93 73 Bob, K4TAX On 2/6/2020 3:07 PM, Rick Bates, NK7I wrote: Running low output power from it, is far less efficient than pushing it hard (compare wattages consumed to RF watts output delivered at different output levels); which may have stressed the finals. Ideally you run the previous stages at low-moderate power for lower IMD, then punch it up with the amp. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] VFO B dead
On 2/6/2020 10:03, Gary K9GS wrote: Hi All,I finally found some time this morning to take apart my K3.Removing the front panel was relatively easy. I swapped the VFO A and VFO B encoders and I did have a defective VFO B encoder .I've ordered a replacement encoder from Elecraft, $60 plus shipping. 73,Gary K9GS I haven't had any failures, but a while ago I ordered some spare encoders and pots for my K3, just in case they aren't available in the future. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KX2 ... Any KX2 users on this list?
I can confirm the good reports on the KX2. I've been using mine for a couple years for portable operations, without a hitch. The receiver sounds almost as good as my K3. The battery is good for 5 or 6 hours of CW contest operation at 10 W. If you really want to keep the weight down, the KX2 battery can charge a phone. A modified USB car charger plugs into the battery connector. That battery could charge a phone several times. One very slight annoyance is that Elecraft never fixed the filter software: It only works at bandwidths of odd multiples of 50 Hz: 250, 350, etc. I happen to like mine at 400. 73, Scott K9MA On 1/30/2020 22:20, Joseph Shuman via Elecraft wrote: I have been using a KX2 with the ATU a little over a year, my first and only radio. I love it and have had great success in field throwing a 58’ wire up a tree and a 13’ counterpoise on the ground. Been experimenting with different antenna at home, so far a folded dipole using about 128-130’ of wire being the best performer on 80/40/20m. I put together an external power supply using a security system sealed 12V battery in a small plastic ammo box, an auto lighter plug and a cheap voltmeter. I have operated for over two hours at 10W using this battery rig and the whole station fits in a small $15.00 backpack. You are not mistaken, however, posts regarding the KX2 are few and far between. The radio is simply that good! Keeping Watch- shu Joe Shuman, KE8KJZ On Jan 29, 2020, at 22:05, Charles G. Saunders wrote: Hi all, Just curious, I haven't seen much of anything on the KX2's here. My first Elecraft rig and really having a good time learning. 73, KW4CZ Gordon __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA500 on AM...
Isn't peak power for AM 4 times the average (carrier) power? 73, Scott K9MA On 1/23/2020 18:10, Don Wilhelm wrote: John, The KPA500 is rated for 500 watts PEP. With AM, that is 250 watts carrier, and 250 watts of sideband energy (125 watts for each sideband). So your "talk power" is 125 watts, compared to 500 watts SSB. Note that is for 10 minutes transmit with a 5 minute receive period. If you are "long winded" and want to exceed that 10 minutes keydown, you should reduce the power. See the specifications. If you want to exceed the specification limits, you do so at your own peril, although the KPA500 has means to protect itself. 73, Don W3FPR On 1/19/2020 12:43 PM, Macy monkeys wrote: One more question then I'll go back into hibernation. What is considered a safe drive level for the KPA500 when operating AM? I haven't tried it yet but I imagine the cooling fan goes into jet takeoff mode. Thanks, John K7FD __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Ameritron 240V inrush limiter: any benefit on a KPA500?
On 1/18/2020 12:14 PM, Victor Rosenthal wrote: The power switch in some of those amps like the SB220 or TL922 is highly stressed. T Another cause of high input current is transformer saturation. If the core happened to be fully magnetized in one direction when last turned off, and the AC happens to want to magnetize it more in the same direction at turn-on, the core can saturate for half cycle. It's a random event, which doesn't happen often, but it's hard on switches. It can also make that "bong" sound at turn-on. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Full Break-In (QSK)
Yes, I did those mods to my FT-1000D long ago. It helped, but it's still pretty bad. I can detect the FT1000's a (couple thousand) mile(s) away on the P3. 73, Scott K9MA On 1/17/2020 14:14, Jim Brown wrote: On 1/17/2020 11:56 AM, K9MA wrote: The FT-1000 is notorious for its key clicks There were hardware mods to significantly reduce the clicks, but even then the FT1000-series is a pretty broad rig by modern standards, as are current production Yaesu rigs. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Full Break-In (QSK)
The dits are a bit short on the FT-1000 in QSK mode, but I don't know how much difference that makes. The FT-1000, in any case, is much slower that some of the receivers I used long ago. Alas, I have none of them to test. The FT-1000 is notorious for its key clicks, the reason I don't use it any more. I don't think that is related to QSK, as it's just as bad in PTT mode. 73, Scott K9MA On 1/17/2020 05:17, E.H. Russell wrote: As I recall the FT-1000D accomplished that by shortening the dits and producing an astonishing clatter. THANKS, 73 ED W2RF -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of K9MA Sent: Friday, January 17, 2020 12:26 AM To: elecraft@mailman.qth.net Subject: [Elecraft] Full Break-In (QSK) One of the things I miss is being able to hear between the dits, not just the letters. I know part of that is due to the inherent latency of DSP filters. In any case, I finally got around to actually measuring it. I just used a keyer with 50 percent weighting, and N1MM to set the speed. I found that the K3 could just barely hear something between the dits at 22 wpm, while my old FT-1000D could at 34 wpm. Both at 500 Hz bandwidth, fast AGC. The K3 has the new synthesizers. I did the test by listening to an S-7 carrier and sweeping the RIT back and forth while transmitting dits. Below the above speeds, I could just detect the change in pitch. Increasing the bandwidth and turning off the AGC didn't make much difference. I didn't try the QRQ mode on the K3. It will be interesting to see how the K4 compares. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to e...@qrv.com -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Full Break-In (QSK)
One of the things I miss is being able to hear between the dits, not just the letters. I know part of that is due to the inherent latency of DSP filters. In any case, I finally got around to actually measuring it. I just used a keyer with 50 percent weighting, and N1MM to set the speed. I found that the K3 could just barely hear something between the dits at 22 wpm, while my old FT-1000D could at 34 wpm. Both at 500 Hz bandwidth, fast AGC. The K3 has the new synthesizers. I did the test by listening to an S-7 carrier and sweeping the RIT back and forth while transmitting dits. Below the above speeds, I could just detect the change in pitch. Increasing the bandwidth and turning off the AGC didn't make much difference. I didn't try the QRQ mode on the K3. It will be interesting to see how the K4 compares. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT: Australian fires
In Australia, there are sheep stations the size of Belgium! 73, Scott K9MA On 1/2/2020 10:37, Rick M0LEP wrote: A few days back I heard that the area burned so far during this fire season in Australia could best be measured in terms of the size of Wales or Belgium. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 - Power cable voltage drop
Typically, there are small resistors at the power supply between the output and sense terminals to prevent the voltage from rising if a sense wire opens up. 73, Scott K9MA -- Scott Ellington --- via iPad > On Dec 24, 2019, at 5:39 PM, Bob McGraw K4TAX wrote: > > Yes, but one screw-up on the remote sensing system and it will take > advantage of the voltage overhead on the pass transistors and likely wipe out > every piece of equipment. I strongly do not advise it. And you make a > valid point for NOT using remote sensing. > > 73 > > Bob, K4TAX > >> On 12/24/2019 3:22 PM, Jim Rhodes wrote: >> I have thought about doing that. Just requires a 2 wire hookup with small >> gauge wire. But I run all of my small items like the remoterig box, LP-pan >> box, VHF/UHF rig and so forth off of the main supply and if I have a larger >> than anticipated voltage drop on rig power cable the voltage on the other >> tings could go fairly high. The power supply is a HB thing with at least a >> 50 amp capacity and plenty of voltage overhead before pass transistors. >> (Used to run 2 HF rigs before downsizing.) >> >> >>> On Tue, Dec 24, 2019 at 2:25 PM Rose wrote: >>> >>> First, it would require some basic technical skill ... (;-) >>> >>> 73 >>> >>> K0PP >>> >>> On Tue, Dec 24, 2019, 13:20 Karin Johnson >>> wrote: >>> >>>> Why hasn't anyone used remote sensing at the radio voltage input? >>>> As far as I know all of the Astron supplies don't have external sense >>>> wiring. Many so called professional grade high current supplies provide >>>> For external connection of the voltage sense back to the regulator chip. >>>> I've toyed with this idea a bit but haven't had the time dig in to the >>>> Astron supply I have. If this were implemented then one could maintain >>>> 13.8 volts or whatever you desired at the radio power supply inputs, >>>> Regardless of the current draw. >>>> >>>> Karin Anne Johnson K3UU >>>> >>>> >>>> __ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:Elecraft@mailman.qth.net >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> Message delivered to elecraftcov...@gmail.com >>>> >>> __ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to jimk...@gmail.com >>> >> > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 - Power cable voltage drop
There can be stability issues with remote sensing. Also RF susceptibility. Take care! 73, Scott K9MA -- Scott Ellington --- via iPad > On Dec 24, 2019, at 4:03 PM, Don Wilhelm wrote: > > That would be a neat thing to do, but DO NOT do that on a power supply that > is connected to anything other than the rig you are sensing from. > > The voltage on other devices connected to the power supply will increase when > you transmit on the rig to which the sense wires are connected. > > Use a separate power supply for accessories. > > If you need to use the same supply, you can adjust the voltage upward - the > SS30 sold by Elecraft already has an output voltage of 14.1 volts. > Still use a separate power cable to the transceiver and another cable to any > distribution box that you use for accessories for best results (lowest > voltage drop when transmitting). > > 73, > Don W3FPR > >> On 12/24/2019 4:23 PM, K4HYJ via Elecraft wrote: >> I do use voltage sensing at the rear of the radio. Astron supplies can be >> modified easily to do this - they already have sense wires tied to the >> voltage output terminals. Basically you disconnect them there and run leads >> (keep em short) to the radio. On transmit, my K3s drops less than 1/10 a >> volt. >> There are a few write ups floating around on how to do this. I installed a >> switch (make before break type) on my RS-50M so I can return to "normal" >> sensing. ***WARNING*** If the external sense wires are not connected to >> anything the crowbar circuit will fire!!! > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 10 Meters
Hi Eric, I was able to tighten those screws a little, but it made no difference. Adding ferrites to the control cable near the PS helped slightly, suggesting that that is the source. The RF is definitely being received by the antenna, about 100 feet away: its strength depends on the antenna direction, and it is at least 7 dB weaker with a dummy load. I have submitted a request to tech support. 73, Scott K9MA On 12/17/2019 13:44, Eric Swartz - WA6HHQ, Elecraft wrote: Hi Scott, We have seen this in rare cases on a few 1500s. It appears to be caused by the ground connection between the rear RF INPUT SO-239 flange and the chassis. Very slightly loosening (not too far!) and then firmly re-tightening all four screws on this SO-239 connector will insure a good ground connection between this connector and the rear panel. (There are lock washers between the nuts and the SO-239 inside.) If the screws are loosened too far, you may have to remove the bottom cover of the amp to hold the interior nuts in place while you re-tighten the four screws. (Make sure the 50V power and control cables are disconnected when you remove any covers on the amp.) 73, Eric /elecraft.com/ On 12/14/2019 1:43 PM, K9MA wrote: I guess it just shows how little I've been on 10, but I've had the KPA1500 for over a year now, and I just noticed that when I turn it on, my noise floor on 10 goes up about 3 dB. (And that's from an urban noise floor.) It's pretty flat over much of the band, not typical switching supply noise. Has anyone else experienced this and found a cure? (Other than using the old amp tube.) 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 10 Meters
Chris, In my case, the noise is present any time the KPA1500 is turn on. Its effect depends only on the direction my beam is pointed, as both my noise level and the amplifier noise vary with direction. In the worst case, I'm seeing about a 5 dB increase from my high urban noise floor. I think the effect would be far more dramatic in a quiet location. (My antenna is about 100 feet from the amplifier, which is in the basement.) 73, Scott K9MA On 12/16/2019 16:16, Chris Codella, W2PA wrote: Scott, I noticed the same thing this last weekend, having not been on 10 much since getting the amp. But I found the noise to be quite variable. It doesn't always occur. When it does, it appears suddenly, out of the blue while operating. Sometimes I could make it go away by turning off the power, waiting a while, then restarting. I also got it to stop a couple of times by sending a single "dit" while in operate mode. Quite strange. I'm trying to get more data but it does seem to be an intermittent thing and hard to replicate. This noise didn't affect any band below 10m but appeared very broad-banded above, using an SDR receiver. 73, Chris, W2PA On 12/14/2019 4:43 PM, K9MA wrote: I guess it just shows how little I've been on 10, but I've had the KPA1500 for over a year now, and I just noticed that when I turn it on, my noise floor on 10 goes up about 3 dB. (And that's from an urban noise floor.) It's pretty flat over much of the band, not typical switching supply noise. Has anyone else experienced this and found a cure? (Other than using the old amp tube.) 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 RFI on 10 Meters
Hi Pete, It did help to put a couple ferrites on the PS control cable. It's now barely perceptible, but that's with an urban noise level. It's definitely coming in via the antenna, something over 100 ft away. 73, Scott K9MA On 12/14/2019 21:03, N4ZR wrote: I just tried that with my KPA-1500, Scott, and could not hear any change. Another one of those RFI gremlins! 73, Pete N4ZR Check out the Reverse Beacon Network at <http://reversebeacon.net>, now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. On 12/14/2019 4:43 PM, K9MA wrote: I guess it just shows how little I've been on 10, but I've had the KPA1500 for over a year now, and I just noticed that when I turn it on, my noise floor on 10 goes up about 3 dB. (And that's from an urban noise floor.) It's pretty flat over much of the band, not typical switching supply noise. Has anyone else experienced this and found a cure? (Other than using the old amp tube.) 73, Scott K9MA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 RFI on 10 Meters
I guess it just shows how little I've been on 10, but I've had the KPA1500 for over a year now, and I just noticed that when I turn it on, my noise floor on 10 goes up about 3 dB. (And that's from an urban noise floor.) It's pretty flat over much of the band, not typical switching supply noise. Has anyone else experienced this and found a cure? (Other than using the old amp tube.) 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K3 Parts
I'm thinking it might be a good idea to stock up on K3 parts I might need in the future, when they may not be available. Two likely candidates are the main VFO encoder and the AF/RF gain pots. Any other suggestions? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 ATU operation
One thing that may confuse things is that the frequency counter has only 8 kHz (?) resolution, and it takes priority over data from the radio. I'm unsure about this, as my KPA1500 doesn't often seem to change ATU setting when start transmitting. It is possible, though, that the low resolution counter thinks the frequency is in an adjacent bin. If it were up to me, I would not allow the counter to have priority unless the frequency difference is at least several bin's worth. That way, transmission wouldn't be needlessly interrupted because of the low counter resolution, but the amp would still be protected against erroneous data from the radio. But Dick probably has more important things to worry about. 73, Scott K9MA On 12/11/2019 11:34, char...@k5ua.com wrote: I should have checked for a new manual since the manual that came with my KPA-1500 has 20 Kc bins which I see are now 10 Kc bins. In addition, the tuning frequencies have been changed to 10 Kc increments. I think that is why I was getting unexplained results from the tuner as I tuned across the band. I will "re-teach" the KPA-1500 using these new parameters. Just to make sure, however, does everyone agree the current concept is the first bin on 80m would be 10 Kc wide (3.500 to 3.510) and the correct tune-up frequency to "teach" the KPA-1500 for that bin would be 3.505 Kc ? Secondly, the KPA-1500 would proceed to the next "taught" tuning parameters (at 3.515) when the xcvr frequency would cross into the next bin slightly higher than 3.510 ? Would appreciate all interest parties to agree or disagree with this scenario. Thanks for all the comments, I'm glad Electraft made the bin size smaller because feedpoint impedances can change rapidly on 80M. Thanks, K5UA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 ATU operation
I understand that the ATU uses 10 kHz segments on 80, which was at some point changed from 20 kHz. That means the center points are 3505, 3515, etc. There is some hysteresis when tuning, but I'm not sure that consistently explains where it switches. It also won't switch until you stop tuning for 1/2 second, or so. Another factor is that the ATU only measure frequency to, I think, 8 kHz. The net result may be that sometimes it's not in the frequency segment you think it should be in. Unless you have a very narrow band antenna, it shouldn't make much difference. 73, Scott K9MA On 12/10/2019 17:03, char...@k5ua.com wrote: After saving my KPA-1500 ATU impedance matching parameters on 80M at 20 Kc intervals (3.510, 3.530, 3.550, 3.570, etc, etc), I expected that the KPA-1500 ATU would automatically switch to the next set of L/C values at the midpoint of the 20 Kc segments (like 3.520, 3.540, 3.560, etc, etc), but I find that it switches randomly, sometimes just 2 Kc away from the main tuning frequencies. Does anyone have information on how the ATU is supposed to work when it is polling the xcvr for frequency? Thanks, K5UA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRQ + and the K4 question
With AGC-F set to 200, "new" QSK, tnd the new synthesizers, I can just barely hear between the dots at 24 wpm. (non-QRQ mode). That's the only thing a miss about my old FT-1000D. No one misses the key clicks. 73, Scott K9MA On 12/6/2019 12:26, Wayne Burdick wrote: The K3 can only hear between words above about 10 wpm, and QRQ mode doesn't help much. This depends on how the K3 is configured. There are two QSK settings (see CONFIG:CW WGHT menu entry), and with one of them, along with proper adjustment of AGC, it's possible to hear between dots at well over 20 WPM. The new synthesizer (KSYN3A) also improved QSK times. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] QRQ + and the K4 question
A related question: Will the latency and turn-around time of the K4 be fast enough for true QSK operation? The K3 can only hear between words above about 10 wpm, and QRQ mode doesn't help much. 73, Scott K9MA On 12/6/2019 09:13, Wayne Burdick wrote: As an SDR, the K4 has no need to shift an oscillator between RX and TX mode. So there’s no need for “QRQ mode.” Wayne N6KR elecraft.com On Dec 6, 2019, at 3:58 AM, Steven G. Steltzer wrote: Will the K4 do away with the annoyance of the RIT/XIT turning off QRQ+ mode? Thanks, Steve, WF3T __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to n...@elecraft.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K4: savable profiles?
On 11/27/2019 19:09, Walter Underwood wrote: Split the options from the calibration parameters. I'll second that. For example, it would be great to be able to take all those option setting on my radio, put them on a USB stick, and load them on another radio at a multi-op station. Obviously, one would not want to change the calibration of that radio. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 wish list
When you QSY, without switching antennas, it seems to take half a second or so after you stop tuning for the ATU to switch. (Assuming it's been "trained".) As far as I can tell, after that delay the ATU is stable, so it shouldn't affect outgoing CW. However, as Pete says, when you switch antennas there can be a delay, since the only way the ATU knows you have switched antennas is the high SWR when you start transmitting. The solution is a way to tell the ATU that you have switched antennas BEFORE transmitting, for example, by tying it into the switch(es) which controls the external antenna relays. Imagine this scenario: You hear a weak signal calling CQ, flip your antennas switch a couple time to figure out where it is coming from, and then you have about 100 ms to start calling. Otherwise it's too late. With two tribanders, this happens to me all the time. How can the KPA1500 ATU be made to switch that fast? It's relays certainly can; it's just a matter of getting that control signal to them. I doubt there is any way to modify the KPA1500 to make this happen without changes to firmware. 73, Scott K9MA On 11/20/2019 08:40, N4ZR wrote: I hope that the amp guys at Elecraft will reply to this thread. I've been working with them for several weeks trying to address just this problem. The latest beta firmware seems to handle it pretty well, so long as I make sure I've trained the ATU on every band segment. I'd love to have 50-ohm resonant antennas on every band. Short of that, there does not appear to be any way around the ATU's need to identify which antenna is selected by the external switch, before it can decide which stored setting to apply. This takes a measurable amount of time, as much as one character of 30 WPM CW, and I'm told that until this process is completed, the amplifier is bypassed. I've observed, for example, that when I pounce on a CQer significantly far away from the frequency of my last QSO, the "N" in my call becomes "E", or goes away entirely, as heard by the other station. 73, Pete N4ZR Check out the Reverse Beacon Network at <http://reversebeacon.net>, now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. On 11/19/2019 3:56 PM, K9MA wrote: Bill is touching on an issue I've raised before: A way to select multiple ATU settings for the same frequency and antenna output. I had to build a tri-band tuner to switch between my two tribanders so they would both present the amplifier with the same impedance. The internal ATU would have been able to do that, if only there were a way to store and recall two different sets of settings. In the case of automated antenna switching systems like mine, there also has to be a way to electronically tell the amplifier which settings to use: Having to press a front panel switch is not acceptable, as that would require two operations to switch antennas, which is way too slow. (I sometimes have to flip the antenna switch several times during a call to determine which antenna to use.) 73, Scott K9MA On 11/19/2019 13:02, K8TE wrote: Another issue not explicitly mentioned is using an external antenna switch with different conjugate matches already trained withing the KPA1500 ATU. Those different matches mean when one selects a "new" (different) antenna than already selected on a particular frequency (same band or not), the KPA1500 doesn't know this fact until power is applied. Then, due to a high VSWR, the amplifier faults. With just two antenna ports on the KPA1500, there are only two quickly accessible tuning solutions per frequency if using both ports. If using only one port and an external antenna switch, a common choice in many stations, finding the correct tuning solutions can't be done fast enough to prevent a fault. As alluded to in previous messages on this topic, perhaps the solution, unfortunately, is an external box that could contain the appropriate data so that, when a new frequency/antenna combination, that has a previously tuning solution, is selected, the external box will tell both the KPA1500 ATU to select the appropriate solution and transceiver to make appropriate power level adjustments, both PRIOR to actually transmitting. This is done (approximately, but with no power level changes) by the KAT500 in selecting one of the three antenna ports and the appropriate tuning solution. This assumes no other antenna choices on each of the three ports for the same frequency. The KPA1500/K3S combination is (currently) not sufficiently "smart" to accomplish this. Of course, if we had "perfect" antennas that provided resonant matches on all bands/frequencies, we wouldn't be discussing this. If we had those, we wouldn't need the KPA1500 ATU either. 73, Bill, K8TE -- -- Scott K9MA k...@sdellington.us _
Re: [Elecraft] KPA-1500 wish list
Bill is touching on an issue I've raised before: A way to select multiple ATU settings for the same frequency and antenna output. I had to build a tri-band tuner to switch between my two tribanders so they would both present the amplifier with the same impedance. The internal ATU would have been able to do that, if only there were a way to store and recall two different sets of settings. In the case of automated antenna switching systems like mine, there also has to be a way to electronically tell the amplifier which settings to use: Having to press a front panel switch is not acceptable, as that would require two operations to switch antennas, which is way too slow. (I sometimes have to flip the antenna switch several times during a call to determine which antenna to use.) 73, Scott K9MA On 11/19/2019 13:02, K8TE wrote: Another issue not explicitly mentioned is using an external antenna switch with different conjugate matches already trained withing the KPA1500 ATU. Those different matches mean when one selects a "new" (different) antenna than already selected on a particular frequency (same band or not), the KPA1500 doesn't know this fact until power is applied. Then, due to a high VSWR, the amplifier faults. With just two antenna ports on the KPA1500, there are only two quickly accessible tuning solutions per frequency if using both ports. If using only one port and an external antenna switch, a common choice in many stations, finding the correct tuning solutions can't be done fast enough to prevent a fault. As alluded to in previous messages on this topic, perhaps the solution, unfortunately, is an external box that could contain the appropriate data so that, when a new frequency/antenna combination, that has a previously tuning solution, is selected, the external box will tell both the KPA1500 ATU to select the appropriate solution and transceiver to make appropriate power level adjustments, both PRIOR to actually transmitting. This is done (approximately, but with no power level changes) by the KAT500 in selecting one of the three antenna ports and the appropriate tuning solution. This assumes no other antenna choices on each of the three ports for the same frequency. The KPA1500/K3S combination is (currently) not sufficiently "smart" to accomplish this. Of course, if we had "perfect" antennas that provided resonant matches on all bands/frequencies, we wouldn't be discussing this. If we had those, we wouldn't need the KPA1500 ATU either. 73, Bill, K8TE -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 wish list
Gain control within the KPA1500 just wouldn't be practical. It would require addition of some sort of high power variable attenuator. Slow feedback to the K3, however, only requires some added firmware. No, it wouldn't work with other transceivers, but that's life. Perhaps someone would like to design an external box or write some PC software to perform that function. 73, Scott K9MA On 11/19/2019 06:55, Andy Durbin wrote: "Yes, ALC that really worked well with an amplifier would make the above unnecessary, but I don't think anyone has figured out how to do that. Until someone does, a slow feedback loop adjusting drive power would solve the problem above, not introduce any distortion, and save us operators the bother of riding the power control." The significant problem with implementing closed loop power control is that it would only work (if it could work at all) with an Elecraft transceiver connected by the AUX cable. The KPA1500 is marketed as being compatible with non-Elecraft transceivers. Gain control contained within the KPA1500 would be an advantage to all KPA1500 owners, not just those with a fully integrated Elecraft transceiver. Andy, k3wyc __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 wish list
On 11/18/2019 21:52, Paul Baldock wrote: I also have WET and DRY settings for one of my antennas that are selected by PF1 (^PB). Ah, but there can be more than two setting. A little wet, or a lot wet. Or, in the case of one of my antennas, varying amounts of frost. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 wish list
There are a couple issues here. First, even if the SWR is 1.2:1, about the best the KP1500 ATU firmware can do, across the whole band, the power can still vary a lot. It depends on the actual load impedance, which, at 1.2:1 could be anywhere from 42 to 60 Ohms. If you happened to be at 42 Ohms when you set the power to 1500 W, it could possibly go up to 2100 W elsewhere in the band. (Except, of course, that the KPA1500 won't let you do that.) The other issue is the temperature dependence: I find I have to reduce drive by about 20 percent when the amplifier is cold, or it will fault. Both of these problems could be solved by a slow feedback mechanism which adjusted the K3 output like we do manually. It might even remember previous settings as a function of PA temperature and frequency. The second issue is that this is nothing like conventional ALC, a relatively fast feedback loop. ALC has proven to be highly problematic, so let's not go into that again. It's an entirely different issue. Yes, ALC that really worked well with an amplifier would make the above unnecessary, but I don't think anyone has figured out how to do that. Until someone does, a slow feedback loop adjusting drive power would solve the problem above, not introduce any distortion, and save us operators the bother of riding the power control. 73, Scott K9MA On 11/18/2019 20:32, N4ZR wrote: Jim, I think Paul is talking about something different here. On Page 18 of the manual it describes tapping the ATU Tune button again within 3 seconds of completing the initial tune, to get closer yet. I just tried it, and it works well so long as you have trained the tuner for both antennas on every segment. Unfortunately, there appears to be no way to actually transmit the first character at full power when changing antennas or QSYing bigly. I understand the tuner bypasses the amp until it has determined which setting it should use, which it can only do by learning what the load looks like by actually sending power into it. 73, Pete N4ZR Check out the Reverse Beacon Network at <http://reversebeacon.net>, now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. On 11/18/2019 8:18 PM, Jim Brown wrote: On 11/18/2019 11:34 AM, Paul Baldock wrote: I have manually tweaked (with amp in standby and running 50W) my auto learned atu settings to get as close to 0W reflected power as possible. Yes, and this is exactly what the manual says to do -- before using the amp, train the tuner by tuning at multiple frequencies in each band, AND for each antenna that you use on that band. The tuner is smart enough to select between multiple "trainings" when you use more than one antenna. 73, Jim K9YC __ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Monitor on Line Output
Thanks, Ken. I didn't think to check the firmware release notes. That feature was added in 2017. 73, Scott K9MA On 11/17/2019 16:39, Ken K6MR wrote: I think you are looking for the Tx line out monitor level. LIN OUT (from Config menu) and press 2. 0 should give you no monitor output. Ken K6MR *From: *K9MA <mailto:k...@sdellington.us> *Sent: *Sunday, November 17, 2019 14:29 *To: *elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net> *Subject: *[Elecraft] K3 Monitor on Line Output On SSB, I have the monitor level set to zero, and hear nothing in the headphones. However, when I record the audio from the line outputs, I get my own audio when transmitting, at a much higher level than the rx audio. (LIN OUT nor 050) (No, it's not the mic on another headset connected to the computer.) I can't find anything in the manual about this. At the very least, it would be helpful to be able to match the levels of the TX and RX audio. Am I missing something? Any suggestions? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@outlook.com -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] K3 Monitor on Line Output
On SSB, I have the monitor level set to zero, and hear nothing in the headphones. However, when I record the audio from the line outputs, I get my own audio when transmitting, at a much higher level than the rx audio. (LIN OUT nor 050) (No, it's not the mic on another headset connected to the computer.) I can't find anything in the manual about this. At the very least, it would be helpful to be able to match the levels of the TX and RX audio. Am I missing something? Any suggestions? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K-4 features
Hi Wayne, That's the sort of thing I was thinking of. I think Collins did something like that back in the 50's. Even if it meant dedicating the sub RX to noise detection, it would be worthwhile in high noise environments. I've thought of trying to modify the K3 to do something like this, but I've never found the K3 NB to be all that effective, even when the band was empty. The above would work in the HDR mode, of course. I was also wondering if there might be a way to do this with the SDR, without tying up the sub RX. 73, Scott K9MA On 11/11/2019 10:17, Wayne Burdick wrote: Hi Scott, We could trigger the main RX noise blanker from the sub RX, though we haven't tried this yet. I believe this would achieve what you're describing. For example, the sub RX could be tuned to 13.975 while the main is tuned to the 20 meter CW band. 73, Wayne N6KR On Nov 10, 2019, at 7:12 PM, K9MA wrote: On 11/10/2019 19:06, Wayne Burdick wrote: The K4, being an SDR, provides access to a different class of wide-band NR and NB algorithms. Some hardware noise blankers are very effective at reducing line noise and other impulse-type noise, provided there are no strong signals within the 15 kHz + NB bandwidth. (My old FT-1000D, for example.) With appropriate firmware, could the K4 NB achieve that kind of performance? Could the strong signal limitation be overcome by having the SDR detect noise in a slightly different frequency range, like just outside a ham band during a contest? -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K-4 features
On 11/10/2019 19:06, Wayne Burdick wrote: The K4, being an SDR, provides access to a different class of wide-band NR and NB algorithms. Some hardware noise blankers are very effective at reducing line noise and other impulse-type noise, provided there are no strong signals within the 15 kHz + NB bandwidth. (My old FT-1000D, for example.) With appropriate firmware, could the K4 NB achieve that kind of performance? Could the strong signal limitation be overcome by having the SDR detect noise in a slightly different frequency range, like just outside a ham band during a contest? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA500...standby vs. operate
I guess I'm old-fashioned, but I still don't quite trust this thing with all the software. So I have an actual mechanical "switch" between the computer and the radio. When I turn it off, there is absolutely no way Windows can transmit. (It's also handy when the computer goes berserk in the middle of a contest.) But the radio also has this software stuff in it, so I put the amplifier in standby, the idea being that 100 W probably won't do as much damage as 1500. Unless, of course, I deem it worth the trouble to turn off the other switches. 73, Scott K9MA On 10/27/2019 21:26, Bill Weaver wrote: The danger that I find is leaving my K3 under windows rig control. I once found it sending out a string of dashesagter being left "on" (No the keyer paddle wasn't the cause:-)). I too am in the habit of throwing it into test mode when I leave it alone. 73, Bill WE5P -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT sort of. Charging Lithium Ion batteries
I think pretty much all Li-ion chemistries can be charged at constant current to 80 percent, then at constant voltage. The last 20 percent takes a long time. The charging is terminated when the current drops below a certain limit in the constant voltage mode. This is mandatory: they cannot be float charged like other types. I think all the Li-ion charge controller chips do this. See: https://batteryuniversity.com/ 73, Scott K9MA On 10/26/2019 17:39, Don Wilhelm wrote: I have Lithium batteries in my laptop, my KX2, my electric razor, a tactical flashlight, and maybe some other things. I use the dedicated chargers for each of them. I think the dedicated, automatic chargers fill the batteries to 100%, so there must not be a lot of caution to only charge them to 80%. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3S
On 10/26/2019 13:38, hawley, charles j jr wrote: One thing I remember when I got the P3 how much room it had into it. I thought at the time that a perforated top cover and a speaker would be a good accessory kit for it. That wouldn't be hard to do yourself. Once the P3 is out of warranty, of course. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500: Widely varying drive requirement - same frequency, different antenna
Based on my experience, the KPA1500 is very sensitive to small changes
in load impedance (SWR) with respect to power gain and current. The ATU
software is much better than it started out, but still sometimes doesn't
get below 1.2:1. That could result in the kind of power gain variation
Pete is seeing.
73,
Scott K9MA
On 10/23/2019 12:24, Jim Rhodes wrote:
Actually the fact that you were using the internal tuner doesn't change the
chance that with the settings on the auto tuner don't tell you which
direction the tuning of a certain antenna approach unity from. So there
could be twice the variation allowed between the 2 antennas. So if one is
coming from high impedance and stops at say 1.2:1 and the other is coming
from low and stops at 1.2:1 then there is still a considerable difference
between them. Putting an analyser on them to see the starting point the
tuner is working on could explain a lot.
Jim Rhodes
K0XU
On Wed, Oct 23, 2019, 11:17 N4ZR wrote:
Thanks to everyone who replied, either directly or on the list. I'm
sorry, but I forgot to mention one key fact - I was running the amp's
ATU with both of these antennas. Assuming that the amp's power output
measurement is done at the input of the ATU and not the output, and that
the ATU settings for the two antennas ( ATU rRetune SWR and ATU Stop Tun
SWR ) are identical, this really does look to me like a difference in
amplifier gain rather than measurement error.
The antennas are clearly a lot different - in fact the Windom will often
throw a Reflected Power fault when I first switch to it - but it seems
to me that after the ATU they should look the same.
73, Pete N4ZR
Check out the Reverse Beacon Network
at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.
On 10/23/2019 9:55 AM, Bob McGraw K4TAX wrote:
Pete:
The fact it requires more drive with one antenna as opposed to another
says the two antennas do not have the same impedance. This is not at
all unusual. Power measurements, with the methods used in ham radio
applications, are based on voltage measurements with the impedance
presumed to be 50 ohms. Ohms law says P = E²/R thus any change in R
{impedance} will cause a change in Power indicated or measured at a
given point.
A second factor is SWR which is an indication of the relative
impedance between the source {amp} and the load {antenna}. In this
case, as example, a 1.5:1 SWR can be 75 ohms or it can be 33 ohms.
SWR and Power meters are calibrated for 50 ohms and are based on
voltage on the feed line. Again we see that the impedance or the R
part being different will affect the Power. In order to deliver the
same power into a 33 ohm load, the amp is required to deliver more
current and thus more drive is required.
From an RF measurement at a given point with different impedance's we
find:
1500 watts into 75 ohms is 335 volts with a current of 4.47 amps
1500 watts into 50 ohms is 273 volts with a current of 5.47 amps
1500 watts into 33 ohms is 222 volts with a current of 6.74 amps
From the above one can see the amp is required to deliver more current
into a lower impedance and to do so will require more drive power. And
from the above, one can see the voltage on the feed line is different
with different loads. In this regard, in as much as we measure power
as a voltage with a known resistance the power measurements can be in
error. Our power indicating devices are calibrated for 50 ohms.
Any deviation from 50 ohms will thus cause an error in power indication.
A third component of SWR and Power measurements would be Common Mode
Current on the feed line. This is usually current induced on the
outside of the feed line from the power radiated from the antenna.
This common mode current is not measured by our power indicating
instruments. As a side note, Windom antennas are noted to exhibit
high Common Mode Current conditions. The solution for CMC is to have
a good Common Mode Choke at the feed point of the antenna, where the
feed line connects, and also at the station end.
Jim, K9YC, has and excellent paper on the topic:
http://audiosystemsgroup.com/2018Cookbook.pdf
Also, Rick, DJ0IP has a lot of valid information on his site:
http://www.dj0ip.de/balun-stuff/
http://www.dj0ip.de/rf-cmc-chokes/
Now after all of this is said and done, I'd say your results with your
KPA1500 are normal. Hence the reason for the variation in drive is
due to the load impedance presented to the amp and the power
measurement method.
73
Bob, K4TAX
On 10/23/2019 6:59 AM, N4ZR wrote:
I have two 40M antennas, a Carolina Windom and a full-wave parasitic
sloper. I have just noticed that on any given frequency, my K3 must
deliver considerably more power on one than the other, in order for
the amp to produce 1500 watts. The difference is 27 watts on one vs
42 watts on the other.
Re: [Elecraft] K3 VFO-B knob replacement notes
A few years ago, when the VFO B knob on my K3 cracked, Elecraft sent me a free replacement. Recently, one of the smaller knobs split in two. It was entirely made of plastic. I ordered a replacement, which turned out to have a metal insert. Clearly, these should have had the insert in the first place. OK, the radio is 9 years old, so I don't mind paying for the replacements, but still 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 on digital modes
On 8/31/2019 6:02 PM, Roger D Johnson wrote: Isn't this exactly the way some of the first ham linears were designed for an input of 2000 watts in SSB and 1000 watts in CW? There was a switch on the front panel for SSB/CW mode which dropped the plate voltage for CW mode so that the tubes saw the same load impedance they did in SSB mode thereby keeping the efficiency high and not requiring retuning between modes. I think it was more to make it harder to exceed 1 kW input on CW. It is almost always possible to load an amplifier (with the usual PI network) for efficient operation at less than maximum output. It just has to be loaded lightly and not driven too hard. That conflicts, however, with the usual procedure of loading for maximum output. Also, with two plate voltage settings you could usually tune for maximum output at the low setting at about 1 kW input, and it would be tuned about right for 2 kW at the high setting. This reduced the stress during tuning, and probably was the most common strictly legal way to tune for 2 kW PEP input in those days. Actually, legally tuning for 2 kW input in those days was tricky. Collins used a bridge which compared RF input and output voltages and allowed tuning at low power. I used that circuit in an amplifier I built about 50 years ago, and it worked pretty well. A PI network in a tube amplifier allows properly loading the amplifier into a range of load impedances, but the operator or autotuner is looking at grid current, plate current, input/output voltage ratios, etc. to get the tuning right. This sets the tuning for efficient, linear operation. A solid state amplifier and ATU work very differently. The amplifier is designed to operate properly into a 50 Ohm resistive load, and the job of the ATU is to make the actual load as close to that as possible. One result of that is that a rather small mismatch can have a large effect on efficiency and/or linearity. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 Solution to the efficiency problem?
Totally aside from the power meter issue, what you are doing with the ATU is like loading a tube amplifier more lightly with the PI network. Lighter loading will improve efficiency, but may result in more distortion. One reason solid state amplifiers are generally less efficient than tube amplifiers is that transistors (including FET's) become extremely nonlinear when they are driven close to saturation. That is, when the voltage across the device is near zero at the bottom of the cycle. As a result, solid state amplifiers have to be loaded more "heavily", to keep the transistors far from saturation. This, of course, results in more dissipation. I haven't tried it, but it's possible the KPA1500 could be loaded more lightly by manually adjusting the ATU values to improve efficiency on CW or RTTY, where linearity isn't a big issue. That might reduce PA temperature a little, though I'm not sure it would be worth the trouble. Given how sensitive the KPA1500 is to small changes in SWR, though, setting this up across a band would be a tedious process. The rather large variations in PA current I see at 1500 W output at a moderate SWR, like 1.3:1, is probably due to the same effect. (A 1.3:1 SWR could be a load impedance of anything from 39 to 65 Ohms.) 73, Scott K9MA On 8/31/2019 09:15, Roger D Johnson wrote: I think I've discovered a fly in my ointment! The efficiency that the amp displays is based on it's determination of the output power. If the amp is looking into a higher Z load, the indicated power is greater than normal resulting in a higher efficiency reading. Oh well, back to the drawing board! 73, Roger On 8/31/2019 9:32 AM, Roger D Johnson wrote: It occurred to me that the KPA1500's built in tuner might be of some help. Here's my reasoning. If we decrease the drive power to lessen the output power but keep the same voltage, the amplifier wants to see a higher load impedance. Here are the results of some quick tests: Base line is the amp set for 1000 watts output and eff is 44% I the set the tuner so the amp "sees" a load of 60 Ohms (actually) 58 Ohms with the values of L and C available. Eff went up to 53%! I then set the tuner to present a 70 Ohm load (actually 68 Ohms). Eff went up to 59%! This was into a dummy load. I realize that, if you're using the tuner to match an antenna, this could be very complicated. If Elecraft could figure some way to give us a choice of voltages for differing power levels, this problem would go away. 73, Roger -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 on digital modes
This is nothing unique to the KPA1500: ALL class AB amplifiers behave this way. Even an "ideal" class AB amplifier has a maximum dissipation at around half of full output. One thing running at lower output probably will buy you is lower IMD. 73, Scott K9MA On 8/29/2019 08:03, Roger D Johnson wrote: It's interesting that the heat that has to be dissipated is pretty close to 1000 watts in all these scenarios! Running the amp at less than full power buys you nothing. 73, Roger On 8/29/2019 8:38 AM, Larry (K8UT) wrote: Pete, I don't run my amp at full legal limit on digital modes, but typically set the input power for about 1000 watts output. One of the interesting characteristics of the amp is increased efficiency as power increases. At 600 watts efficiency is only 38%, whereas at 1000 efficiency increases to 50% and at 1500 watts to 60%. (see screenshots) -larry (K8UT) -- Original Message -- From: "N4ZR" To: "Elecraft List" Sent: 2019-08-29 07:59:23 Subject: [Elecraft] KPA-1500 on digital modes Elecraft's published specs rate the KPA-1500 for 1500 watts output on all modes. In prepping for this weekend's contest, I've been running it at closer to 700 watts, because I've found that even just running on CW, with its much lower duty cycle, my amp reaches 70C quickly. I don't do that much digital contesting, though, so I'm wondering whether 1500 watts output is on digital modes is realistic or a recipe for trouble. -- 73, Pete N4ZR Check out the Reverse Beacon Network at <http://reversebeacon.net>, now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. ______ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Power Output Variation
Concerning the output variation, I’ve noticed that when I change bands while the amplifier is hot, the output on the new band starts out high, then gradually drops. This would seem to indicate that the LPF is heating, and that the loss in the filter is several hundred Watts. That’s no big deal if the filters are properly cooled, as they apparently are, but still requires manually riding the power control. 73, Scott K9MA -- Scott Ellington --- via iPad > On Aug 26, 2019, at 7:34 PM, Bob Wilson, N6TV wrote: > > As for KPA1500 output power variation with temperature, it is annoying, and > it seems to vary from KPA1500 to KPA1500, perhaps depending on how many > other devices or heat sources are located near the ventilation holes. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA-1500 Power Output Variation
Here’s a way to get a worst case estimate of the effect of SWR on power output. Assume the amplifier has constant VOLTAGE gain and an output impedance much smaller than 50 Ohms. A 1.3:1 SWR means the load impedance could be as low as 39 Ohms or as high as 65 Ohms. Let’s say the SWR is 1:1 at the frequency at which the drive is set for 1500 W output. Then you tune to where the SWR is 1.3:1. At that SWR, the output could be anything from 1150 to 1950 W. The range may be less, as the amplifier output impedance may not be all that low compared to 50 Ohms. In any case, this shows that the power output of a solid state amplifier may be very sensitive to load SWR. This is why the KPA1500 ATU really needs to be able to keep the SWR low. The recently improved autotune firmware does this very well, if you “train” it across the band. It is also why it’s important to use the ATU, even if the antenna SWR is “only”, say, 1.5:1. I keep hoping Elecraft will come up with a way to automatically adjust drive power to maintain constant output. That would also compensate for change in temperature. 73, Scott K9MA -- Scott Ellington --- via iPad > On Aug 24, 2019, at 1:45 PM, Jim McCook wrote: > > I'm using my K-3 with the KPA-1500 and have a problem with extreme changes in > power output with a given drive level on 40m CW. This happens to a lesser > extent on other bands with different antennas. My 40m antenna is tuned to > 7.025 where SWR is 1.1:1. On 7.000 it is 1.4:1 and at 7.050 it's 1.3:1. > Within that range of frequencies the output _without_ the tuner at a given > drive level (30w) varies from 1300w to well over 1700w. Using careful > _tuner_ settings it's only slightly better. I have to reduce drive to 24 or > 25w to get below 1500w, depending on the temperature of the amplifier (power > output varies a lot with temperature changes). Higher temp = lower output. > > I have tried to compensate in the segments where output is excessive by using > manual settings via the Utility. This has helped slightly, but still isn't > adequate. I've resisted using ALC because of concern for generating > distortion. Having to ride the drive level from the K-3 is a PIA, especially > during contests. > > It seems to me a good answer would be to have higher input attenuation so > drive requirement would be higher, maybe around 70+ watts. I'd expect > changing drive level by the same number of watts (5 or 6) would not affect > output as much. I'd also assume the power output would not vary nearly so > much with a given drive level. > > Is this a possible solution? I've also understood that most transmitters > (even the K-3) have cleaner output near highest rated output. > > Help! > > Jim W6YA > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] ALC implementation
I like to think of ALC as receiver AGC in reverse. Done properly, it results in minimal distortion while keeping the signal level nearly constant. As far as I can tell, commercial transceivers have all been doing this pretty well for a long time. What I've never been able to figure out is why it's so hard to close the ALC loop around an external amplifier. If it works with the 100 W amplifier built into the transceiver, why won't it work with a bigger amplifier? (And it seems about universally agreed that it won't.) 73, Scott K9MA On 7/12/2019 23:32, Wes wrote: You do know that the K3(S) uses a slow ALC system for power control don't you? Wes N7WS On 7/12/2019 8:53 PM, Brian Denley wrote: Nothing when that’s what you want. But using ALC to control xcvr power is uncontrolled compression that may or may not be desired. Brian KB1VBF Sent from my iPad On Jul 12, 2019, at 4:09 PM, Wes wrote: And what exactly is the problem with compression? It's used all over the place. Wes N7WS On 6/28/2019 11:38 AM, Brian Denley wrote: I have always thought that ALC is not appropriate for power control. It’s a protection system. Over use of ALC acts like compression. No? Brian KB1VBF Sent from my iPad __ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT a bit: K3 Ant Tuner
One reason to use the internal ATU with an external tuner is so the transmitter can see a low SWR over a range of frequencies, without retuning the external filter. Also, if the external tuner can only get down to, say 2:1, the internal ATU will get it down to 1:1, and the transmitter will be happier. 73, Scott K9MA On 7/5/2019 13:20, Mark Goldberg wrote: I stand corrected. I made an assumption, probably incorrectly, that the reason they had a second tuner was that the first did not successfully tune the antenna. They just decided to put the bandpass filter between the two tuners, which would have provided a mismatch at both the filter input and output. I just used a mismatch at the output as an example. I just provided an example of filter performance degradation with even what would be considered a reasonable SWR. I prefer Jack's solution of bypassing the internal K3 tuner. I do have a situation where my antenna tuner can't tune my antenna on 160. Rather than try to use two tuners in series with the requisite losses, I added a shunt inductor on a big ferrite core to provide most of the required inductance for a match. It gets hot. 73, Mark W7MLG On Fri, Jul 5, 2019 at 10:57 AM David Gilbert wrote: I think you misread the situation. The question isn't whether to put a single antenna tuner between the antenna and filter versus putting it between the rig and the filter. The question is whether putting an ADDITIONAL tuner (the one internal to the K3) at the input of the filter is a good idea. And to me it seems the answer is yes. I think we all agree that the right feed impedance and load impedance for a filter is important. And as I pointed out, not just for power handling, but also for the filter to actually filter as it was intended. 73, Dave AB7E On 7/5/2019 10:18 AM, Mark Goldberg wrote: I could not let this go. I've done a lot of work with bandpass filters. The mismatch will degrade the filter. For an example, I used Elsie, which is a filter calculator. Using the example 20 Meter bandpass filter, the passband loss is about .25 dB with matched 50 ohms in and out. Changing the output impedance to 38+j12 (38 ohms plus 135 nH inductor at 14.15 MHz, about 1.5:1 SWR), the passband losses increase to about 0.4 - .44 dB and vary more over the band. Here are the schematics and plots, anyone is welcome to check my calculations, as I do make mistakes! https://drive.google.com/file/d/1kj31IL_px6nVyRadW4nOi_c6FLgyaRyk/view?usp=sharing The loss in the filter will almost double. For 100W in, the loss goes from about 6W to about 10W. So, it is not a good idea. A worse match will result in even more losses, perhaps overheating and destroying the filter. 73, Mark W7MLG On Fri, Jul 5, 2019 at 8:32 AM Don Wilhelm wrote: Rich, Yes and no. With 2 antenna tuners in-line, there will be a bit more loss due to inductor winding resistance, but other than that, it should do harm. Several bandpass filters indicate that they should be between the rig and the tuner (so the bandpass filters are not run at a high SWR). If the power rating of the bandpass filter is marginal with respect to the rig power, then I would observe that caution. Refer to the bandpass filter specs. 73, Don W3FPR On 7/5/2019 10:57 AM, Rich wrote: To minimize emails direct replies would be nice. I searched the web and could not find an answer. I know there are a ton of smart folks on this list so I thought I would ask. On Field Day at typical setup is : K3 (or any radio) - bandpass filter - External Antenna Tuner - Antenna So the antenna was tuned via the external tuner, but saw a guy then using the K3 ant tuner to touch up the SWR between the radio and the bandpass filter. Is that an acceptable practice? -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] OT a bit: K3 Ant Tuner
On 7/5/2019 12:55, Jack Brindle via Elecraft wrote: OK, so let’s look at the K3 side. The K3 antenna port connects directly to the BPF’s radio port. Again, we are presuming the BPF is designed for 50 ohms resistive source/load. The K3 is designed to transmit into a 50 ohm load, but it may not itself be a 50 ohm source. And, the receiver input may not be 50 ohms as well. Adding a tuned ATU does bring this to 50 ohms, providing a proper match into the BPF, so that optimum signal flows both ways. Bandpass filters are generally designed for 50 Ohm source and load resistances, mainly because the actual source and load impedances are usually unknown. These filters will only perform as advertised with a 50 Ohm source and load. With real world impedances, you just have to hope for the best. It's easy enough to use a tuner or other matching network to get the load impedance close to 50 Ohms in the passband, but even then, the impedance outside the passband may be far different, so filter performance will not match the ideal case. It might be better, or it might be worse. Unless you know the actual impedances, you can't predict it. The source impedance is another matter. The output impedance of a transmitter is almost certainly NOT 50 Ohms. It's probably much lower. After all, an ideal voltage source has an output impedance of zero, and is 100 percent efficient. The ATU matches the LOAD to 50 Ohms, so the transmitter sees a 50 Ohm load, but does NOT necessarily match the output impedance to 50 Ohms. This is another reason real world filter performance almost certainly differs from the ideal. Again, unless you know the source and load impedances over the whole range of frequencies of interest, you can't predict the filter performance. While it's unlikely to happen by accident, it's possible to find a source impedance for any reflective filter which will result in zero (or very little) attenuation at any frequency. It's called a conjugate match. In reality, though, we seem to get pretty good results with these 50 Ohm filters. You can actually measure the parameters that are really important, like harmonic attenuation, and see whether it is good enough. Even then, though, there's uncertainty, as that measurement is usually made with a dummy load. What if the impedance of your antenna at a harmonic isn't 50 Ohms? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 Power Supply Fan Noise
I suspect the reason the power supply fans run at constant speed is that they are part of the Meanwell power supply, and beyond Elecraft's control due to warranty issues, etc. I certainly can't fault Elecraft for using that power supply, as it's cost effective and probably helped get the KPA1500 on the market more quickly. We can hope that perhaps some day Meanwell will switch to a temperature controlled fan. I don't find mine particularly loud, as the RF deck fans drown them out even at their lower speeds. Even the K3 fans will drown it out when I'm running in a CW contest. I use some very good passive headphones, however. I don't think it's realistic to expect to be able to operate with an amplifier in the shack without headphones. However, the KPA1500 is fully capable of remote operation, so you could put it in the next room. 73, Scott K9MA On 6/10/2019 18:57, eric norris via Elecraft wrote: More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch? I complained about this a year ago, and I find it completely unacceptable. No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable. I've tried moving the PS deck around with minimal improvement. This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment. Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck? Why do these fans create such a piercing high-pitched note? If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream? Thanks, 73 Eric WD6DBM Sent from Yahoo Mail on Android __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Switched PS overvoltage
It's far less likely that a switcher will fail to overvoltage. The switching transistor(s) under stress, and most likely to fail, will just cause the supply to die, as you have observed. Still, I don't like entrusting the life of my K3 to one cheap resistor in the feedback loop. That comes of a career designing spacecraft electronics. 73, Scott K9MA On 6/10/2019 11:01, Bert wrote: I haven't experienced that a switched PS causes overvoltage. They usually just die! Bert VE3NR On 6/10/2019 11:12 AM, K9MA wrote: On 6/9/2019 23:16, Bert wrote: How would a switched PS take out a radio? Bert VE3NR Most likely due to overvoltage. Linear supplies are particularly susceptible, as the series pass transistor is under stress and can short. Switching supplies can fail if the voltage feedback loop somehow opens up. I've not heard of it happening, but all it would take would be one failed resistor or solder joint. I use a switching supply for my K3, but I built an external overvoltage protector. Of course, the supply has never failed. BTW, I've found that the fan noise from the Samlex SEC-1235 is never audible above the K3 fans, except during long periods of receive, when the low speed supply fan is just barely audible. (I did the mod, so the supply fan runs at low speed all the time.) If I transmit long enough for the supply fan to switch to full speed, the K3 fans are already running fast enough to drown it out. Not to mention those in the KPA-1500. I'm very happy with the Samlex supply. I've never detected a trace of RFI from it. 73, Scott K9MA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Silent power supply for a K3s
On 6/9/2019 23:16, Bert wrote: How would a switched PS take out a radio? Bert VE3NR Most likely due to overvoltage. Linear supplies are particularly susceptible, as the series pass transistor is under stress and can short. Switching supplies can fail if the voltage feedback loop somehow opens up. I've not heard of it happening, but all it would take would be one failed resistor or solder joint. I use a switching supply for my K3, but I built an external overvoltage protector. Of course, the supply has never failed. BTW, I've found that the fan noise from the Samlex SEC-1235 is never audible above the K3 fans, except during long periods of receive, when the low speed supply fan is just barely audible. (I did the mod, so the supply fan runs at low speed all the time.) If I transmit long enough for the supply fan to switch to full speed, the K3 fans are already running fast enough to drown it out. Not to mention those in the KPA-1500. I'm very happy with the Samlex supply. I've never detected a trace of RFI from it. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Handedness
Gee, I’m left handed, and I LIKE to tune with my right, so I can send with my left. 73, Scott K9MA -- Scott Ellington --- via iPad > On May 31, 2019, at 9:37 AM, Wayne Burdick wrote: > > Even in the case of the K3, the VFO and RIT controls are on the right side of > center. In the K4, with its large display, there’s really no choice but to > group the controls on one side or the other. > > It is possible to invert the transceiver to favor left hand operation. A > system of mirrors can then be used to restore panel text orientation. > > Wayne > N6KR > > > elecraft.com > >> On May 31, 2019, at 6:54 AM, NW0M wrote: >> >> >> Just a peripheral note- the K3 seems not to have a handedness. It works fine >> for either left or right-handed people. The K4 seems obviously a >> right-handed radio with the main tuning knob on the right. I am sure they >> couldn't make a radio with a mirror image of the front panel for lefties. Or >> could they? Doug K6JEY >> >> >> ***Surely you jest >> >> >> >> -- >> Sent from: http://elecraft.365791.n2.nabble.com/ >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K4HD question
On 5/29/2019 22:12, Jim Brown wrote: BEFORE the days of microprocessors, switch-mode power supplies, and other power control systems that use square waves, nearly all man-made noise was impulse noise. NOW, most of the noise that surrounds us is from those microprocessors, switch-mode supplies, and other power control equipment. That noise is NOT impulse noise, and noise blankers cannot act on it. Alas, even in my urban neighborhood, I fear the day is coming when all this electronics generated noise will drown out the line noise. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K4HD question
On 5/29/2019 20:57, Fred Jensen wrote: Noise blankers were designed for repetitive impulse noise, the largest former example of which was ignition noise from vehicles. They have not ever been very effective against power line hash which tends to be non-impulsive and highly random. That has not been my experience. Most line noise IS impulsive, and some noise blankers can be quite effective, but only if there are no strong signals nearby. I'm hoping a direct sampling receiver could avoid that problem. One method that has been used in the (distant) past was a second receiver tuned to a nearby but clear frequency to control the noise blanker. It seems that a direct sampling receiver ought to be able to do something like that. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K4HD question
I've never found the K3 noise blanker to be very effective on power line noise, and I've tried all possible combinations of settings. If the K4 noise blanker were really effective on line noise, I might buy one. 73, Scott K9MA On 5/29/2019 20:39, Wayne Burdick wrote: There are some subtleties in noise blanking that may distinguish the two modes (direct sampling or superhet). The blanking used in direct-sampling should have an advantage on complex, high-duty-cycle noise sources, while the hardware blanking modules used in the superhet may have an advantage with extremely short pulse sources. We'll be extensively testing and comparing them. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Sensitivity - Was K4 Observations
I've often wondered what the effective bandwidth of a good CW operator was. I've noticed that, unless there's QRM, reducing the receiver bandwidth really doesn't help, so the limit factor is the "processing". On the other hand, neither does slowing down below perhaps 15 wpm, as if the processing just can't make the effective bandwidth any lower. Perhaps the real advantage of the JT modes is that they can take advantage of the lower noise bandwidth at very slow speeds, while our brains can't. It would be interesting to compare the performance at 15 wpm. 73, Scott K9MA On 5/19/2019 09:18, Joe Subich, W4TV wrote: On 2019-05-19 9:50 AM, Wes wrote: FT8 reports negative SNRs number but we both know those are bogus. All of the modes that quote negative SNRs are doing so by using SNR in a voice (2500 Hz) bandwidth *NOT* SNR in the detector bandwidth (bandwidth of the final filter whether than be a narrow IF filter, the "ear-brain" filter or a software [computation] filter). If one looks at the SNR thresholds of the various Joe Taylor "slow" modes, 80% of the "negative" SNR can be attributed entirely to the difference between the occupied bandwidth and the [excess] measurement bandwidth. The remainder can be attributed to software processing algorithms that take advantage of the fact that noise is random while the signal is not - in essence reporting using a "peak noise" level while actually decoding against a "minimum noise" level (like copying CW through static crashes - one looses a dit/dah during the crash but fills that in from the context). 73, ... Joe, W4TV On 2019-05-19 9:50 AM, Wes wrote: I feel like I'm gonna be slappin' a tar baby by responding. Since we are discussion HF radios, I was assuming HF. I realize JT65(-HF) and JT9 have been used on HF, but the QSOs are hardly random. If your computer clock is off, sorry, no QSO. FT8 reports negative SNRs number but we both know those are bogus. Wes N7WS On 5/19/2019 5:58 AM, Ed W0YK wrote: JT65, JT9, FT8. 73, Ed W0YK Original message From: Wes Date: 5/19/19 07:49 (GMT-06:00) To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Sensitivity - Was K4 Observations What current modes hear below the noise level? Wes N7WS -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA1500 AC Mains wire colours
Some equipment in NA is wired with both phases plus neutral, so that 120 V is available. Electric clothes driers and stoves, for example, which have light bulbs and sometimes 120 V outlets. (You can imagine what would have happened if 240 V bulbs had been required here.) However, at one time the code did not require separate neutral and ground wires, so the ground was used as the 120 V return. If the ground opens up, your whole stove is suddenly at 120 V. Unfortunately, some of those are still around, and seem to be sort of grandfathered, or just ignored. Hopefully, there's no ham equipment wired that way! 73, Scott K9MA On 5/18/2019 19:16, Jim Brown wrote: On 5/18/2019 4:28 PM, Clay Autery wrote: 230VAC on 3 wires? Never knew they did 3 wire 220V I always assumed it was still 2 hots and ground (plus an optional neutral). Two hots (phases) and ground is three wires. Single-phase power normally comes into a building in North America as two phases and a neutral. We connect a 240V load between the two phases, and a 120V load between one phase and a neutral. It's not unusual to feed a sub-panel with both phases, neutral, and ground so that the panel can feed both 120V and 240V loads. The key here is that loads must NEVER be connected between a phase and ground, ALWAYS between phases or between phase and neutral. You probably know that EU runs on 230/240V, wired phase, neutral, and ground. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K4
I'm very satisfied with my K3, but one feature that might tempt me to buy a K4 would be a really effective noise blanker. It seems to me that a direct sampling receiver ought to be able to do this extremely well. It wouldn't surprise me, though, if the software to do it isn't initially available. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Clipping first element of CW - K3/KPA-1500
Don, I use an external vacuum relay for compatibility with my old tube amplifiers. The whole system long predates the KPA1500, and I still sometimes use the tube amplifier. The system also includes small relays for switching receiving antennas and protecting the receiver. However, even without relays, in QSK there's sound from the receiver between characters, of course, which I sometimes prefer not to listen to. This works fine with the K3, as in QSK/VOX mode closing the PTT circuit simply keeps it in transmit mode. My old FT-1000D doesn't work that way, and it's a pain: if you close the PTT circuit in QSK mode, you get a carrier. I'm glad the K3 doesn't work that way. 73, Scott K9MA On 4/24/2019 09:12, Don Wilhelm wrote: Scott, What do you mean by "if I get tired of all the racket"? The Elecraft gear is all electronic switching for T/R, so no relay clacking racket. That is true for ALL Elecraft gear, even the oldest K2. That may not be true for your old tube amplifiers, but the original question was about a K3 and a KPA1500, so no relay clacking could be present. 73, Don W3FPR On 4/24/2019 9:52 AM, K9MA wrote: I know this will seem incredible to the software purists, but I have an actual mechanical "switch" in series with the PTT line. The K3 is always in QSK mode, but if I get tired of all the racket, I can just turn on the PTT. That seems to work flawlessly with the KPA1500, as well as my old tube amplifiers. (There's another switch in the keying line, just in case the computer goes nuts. Of course, that could NEVER happen.) 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Clipping first element of CW - K3/KPA-1500
I know this will seem incredible to the software purists, but I have an actual mechanical "switch" in series with the PTT line. The K3 is always in QSK mode, but if I get tired of all the racket, I can just turn on the PTT. That seems to work flawlessly with the KPA1500, as well as my old tube amplifiers. (There's another switch in the keying line, just in case the computer goes nuts. Of course, that could NEVER happen.) 73, Scott K9MA On 4/24/2019 08:14, N4ZR wrote: This appears to be, at least in part, a simple matter of RTFM. Also, my manual is 9 years old, and there's obviously been a lot of stuff added since then. Experimentally, it appears that must have *both* QSK on - whether Full or Semi - and VOX on. Once I do this, I see my first dots on the KPA-1500 bar-graph every time. I do not want to use the built-in keyer in the K3, because most of my operating is CW contesting, and I want to use the Winkeyer to send stored messages from N1MM +. The manual makes it clear (if only I'd read it) that both QSK and VOX must be enabled for CW. In PTT mode, it appears that my keyer is sending the PTT signal simultaneously with the first RF - not good. Thanks to everyone who helped put me on the right track. 73, Pete N4ZR Check out the Reverse Beacon Network at <http://reversebeacon.net>, now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. On 4/24/2019 8:49 AM, Bob McGraw K4TAX wrote: See CW QRO and TX DELAY in the menu. Also the benefits and likely issues are described in the manual, page 58 and 66 as MENU items. As to using other means to key the radio and amp and send CW, those may have their own settings as required. While I do not consider myself a high speed CW op, I do work QSK. I do not find any truncation of the first CW element. I use the internal keyer and either a Vibroplex Iambic paddle or a Vibroplex single level paddle. I have VOX set to ON, CW QRO is OFF and TX DLY to NOR and 008. Hope this helps. 73 Bob, K4TAX On 4/24/2019 7:34 AM, Andy Durbin wrote: "It occurs if the rising edge of the keying waveform happens at the same time as the PTT line. The ONLY way around this is to delay the keying waveform slightly so it occurs after the PTT." That would seem to imply that you are not using CW VOX keying. If that is the case then wouldn't using CW VOX eliminate the issue? 73, Andy k3wyc -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Garage door interference
All I did when mine had this problem is to wrap each wire entering the opener around a ferrite core a few times. That included the power cord, the wires to the switches, etc. I think there were 3 cores: one for the power cord, one for the switch wires, and one the light light sensor. Generally, all the wires which run together can go through a single core. No capacitors were necessary. All but the power cord a small enough you can get a lot of turns on a small split core. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Will there be a K4
The top of my list would include a really effective noise blanker. Those of us who don't live way out in the countryside are often plagued with power line noise, which a good noise blanker can largely eliminate. Many older transceivers have noise blankers which are very effective on impulse noise, but only as long as there are no strong signals within 5-10 kHz of the desired signal. The "K4" noise blanker would have the ability to use a second receiver, with a wide IF bandwidth, tuned to a nearby quiet segment, to control the noise blanker in the primary receiver(s). It would be able to automatically find that clear segment. To be effective, the noise blanker receiver has to have a bandwidth of at least 15 kHz, and there can be no strong signals within that bandwidth. Perhaps direct sampling would allow this to be done in software, if the dynamic range were large enough, but it would have to work as well as a hardware version. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA1500 PA Current
Hi Gary, I haven’t seen that problem unless the SWR was at least 1.4:1. However, it’s possible you have hit just the wrong phase angle. If your 1.2 SWR resulted in a load impedance of 42 Ohms, the current could go up 20 percent. On the other hand, 55 A into 50 Ohms sounds a bit high. Make sure the voltage isn’t dropping more than a couple Volts. 73, Scott K9MA -- Scott Ellington --- via iPad > On Mar 15, 2019, at 1:25 PM, Gary J Ferdinand wrote: > > I’m in the process of checking out my amp. I have two dipoles (40 and 80). > At resonance both show a 1.2:1 SWR with ATU totally bypassed. With ATU on, > it remains bypassed on 80, but shows only the ATU ON LED on 40. In both > cases the resultant SWR is 1.2:1. SWR measurements are from the KPA1500 > display. > > When I use the amp with my K3 and drive it up to 1500W, I am occasionally > getting an excessive PA current fault at 63A. From a cold start it’s 60A, > but as it warms up in contest usage I find the power drops off, so I have to > adjust the K3 to bring it back up to 1500W. At that point the PA current > goes over 60A. > > Interestingly, into a dummy load the 1500W point shows a PA current of only > 55A. So the 1.2:1 SWR, be it via a bypassed ATU or using the ATU, is > sufficient to raise the PA current eventually to excessive levels. > > Suggestions? I don’t want this to be flipping out during a contest. I also > don’t want to reduce power into what should be a totally acceptable load. > > 73 > > Gary W2CS > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-1500 tuner questions
The ATU in the KPA1500 alone will achieve the 1.2:1 match with the 2.09 firmware, now in beta. The external tuner is not necessary, unless the antenna SWR is very high. 73, Scott K9MA -- Scott Ellington --- via iPad > On Mar 12, 2019, at 10:24 PM, Peter Dougherty wrote: > > Thanks, Scott! > I'm going to change the way I do things so that ATU is always in, and the > Palstar HF-Auto switches to AUTO mode rather than Manual to keep the match > seen by the KPA below 1.2:1 > > - pjd > > -Original Message- > From: K9MA > Sent: Tuesday, March 12, 2019 1:53 PM > To: Peter Dougherty > Cc: Reflector Elecraft > Subject: Re: [Elecraft] KPA-1500 tuner questions > > Just a general comment on the KPA1500: My experience with it shows that the > SWR has to be below 1.2:1 at the amplifier output (ATU input) to run > reliably at full power. If the SWR is higher than that, the amp will often > fault due to excessive current or drive power before reaching 1500 W. (And > may splatter on SSB.) Elecraft recently updated the ATU firmware to > consistently find a better match, and it really helps. > > 73, > Scott K9MA > > -- > > Scott Ellington > > --- via iPad > >> On Mar 11, 2019, at 8:49 PM, Peter Dougherty wrote: >> >> I have a couple of questions about the KPA1500's internal tuner. >> >> For the most part, I leave the tuner inline. Except for two sub-bands >> (SSB on both 40 and 80m) I am well below 2:1, and maybe 2.5:1 at the >> top end of 160m. The KPA does a good job throughout. >> >> The problems/questions arise when I need to transition between the >> KPA's internal tuner on the bottom ends of both 40 and 80, and the >> external Palstar HF-Auto tuner, which I need to wrangle very high SWRs >> on the phone portions of those bands. Obviously I don't want both >> automatic tuners inline at the same time. The situation is most acute on > 40. >> >> The HF-Auto (external automatic tuner) is bypassed everywhere except >> the range of 3650 to 4000, and 7100 to 7300. I would like to >> automatically have the KPA1500's tuner go into bypass at the above >> ranges, just as the Palstar auto-tuner bypasses outside of those >> ranges. Is this somehow possible, or must I manually switch the tuner >> in and out when I cross the appropriate thresholds? >> >> Second question, and I think this relates to the whole "bins" thing, >> which I don't understand, relates to having different tuning solutions >> on the same band segment. This could be handy for me on 80m. Unlike on >> 40, for 80 I have an inverted vee, and it's easy for me to drop the >> ends and change the length of the antenna, so that instead of being >> resonant at 3550 I could make it 3700. I did this for the ARRL-SSB >> contest and it worked pretty well. Is it possible to have two >> different sets of memorized tuning solutions in the KPA-1500, in the >> event I have the vee set for CW (normal) or SSB (for phone contests only)? >> >> >> - >> 73 and Good DX >> Peter, W2IRT >> >> >> >> President, North Jersey DX Association >> >> DXCC Card Checker >> Letter O Manager, ARRL Incoming 2nd District QSL bureau >> >> >> >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net Please help support this email >> list: http://www.qsl.net/donate.html > > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-1500 tuner questions
Just a general comment on the KPA1500: My experience with it shows that the SWR has to be below 1.2:1 at the amplifier output (ATU input) to run reliably at full power. If the SWR is higher than that, the amp will often fault due to excessive current or drive power before reaching 1500 W. (And may splatter on SSB.) Elecraft recently updated the ATU firmware to consistently find a better match, and it really helps. 73, Scott K9MA -- Scott Ellington --- via iPad > On Mar 11, 2019, at 8:49 PM, Peter Dougherty wrote: > > I have a couple of questions about the KPA1500's internal tuner. > > For the most part, I leave the tuner inline. Except for two sub-bands (SSB > on both 40 and 80m) I am well below 2:1, and maybe 2.5:1 at the top end of > 160m. The KPA does a good job throughout. > > The problems/questions arise when I need to transition between the KPA's > internal tuner on the bottom ends of both 40 and 80, and the external > Palstar HF-Auto tuner, which I need to wrangle very high SWRs on the phone > portions of those bands. Obviously I don't want both automatic tuners inline > at the same time. The situation is most acute on 40. > > The HF-Auto (external automatic tuner) is bypassed everywhere except the > range of 3650 to 4000, and 7100 to 7300. I would like to automatically have > the KPA1500's tuner go into bypass at the above ranges, just as the Palstar > auto-tuner bypasses outside of those ranges. Is this somehow possible, or > must I manually switch the tuner in and out when I cross the appropriate > thresholds? > > Second question, and I think this relates to the whole "bins" thing, which I > don't understand, relates to having different tuning solutions on the same > band segment. This could be handy for me on 80m. Unlike on 40, for 80 I have > an inverted vee, and it's easy for me to drop the ends and change the length > of the antenna, so that instead of being resonant at 3550 I could make it > 3700. I did this for the ARRL-SSB contest and it worked pretty well. Is it > possible to have two different sets of memorized tuning solutions in the > KPA-1500, in the event I have the vee set for CW (normal) or SSB (for phone > contests only)? > > > - > 73 and Good DX > Peter, W2IRT > > > > President, North Jersey DX Association > > DXCC Card Checker > Letter O Manager, ARRL Incoming 2nd District QSL bureau > > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] [ELECRAFT] KPA500 NEW OWNER QUESTIONS.......
Many years ago, I built a tube amplifier with what I thought was a fairly sophisticated ALC circuit. I could never get the ALC loop to be stable. I know a lot more about control systems now, but I still don't know how to get ALC around an amplifier to work, and apparently neither does anyone else. What I don't understand is why it's so hard with an external amplifier, as every transmitter has ALC for its internal 100 W amplifier, and that works fine. Why the same design doesn't work with an external amplifier is the mystery. The problem with just limiting the drive power and using the transmitter's ALC is that, especially for solid state amplifiers, the required drive power can vary considerably with SWR and temperature. That requires either riding the power control continuously or running your amplifier well below rated output most of the time. (Unless, of course, you're running a 2.5 kW amplifier, but that kind of margin is expensive.) So, if anyone could figure out how to get ALC to really work with an amplifier, I think that would be worth paying extra for. 73, Scott K9MA On 2/28/2019 13:12, Bob McGraw K4TAX wrote: Yes, improperly or incorrectly using ALC with any amp or any transceiver, for that matter, can and usually does produce distortion and splatter. Just look at some of the signals on the bands and observe the ALC overshoot which exists with many radios. And it is made worse by the addition of an amplifier in line. It isn't pretty!. Yet it has little impact on the on frequency signal as heard and thus the "great signal" complements follow. But look at the other factors where you will find "NOT so great signal". These points should be addressed as well. 73 Bob, K4TAX On 2/28/2019 1:04 PM, j...@kk9a.com wrote: I have not used ALC with any amplifier since transceivers switched to transistor finals. From what I have read on this list, using ALC improperly can cause distortion. Just be very careful with your drive level. I believe that the KPA500 can handle 100 watts in bypass, 200 watts may be pushing it. The KPA500 is a very nice amp and it is easy to use with any transceiver. GL, John KK9A JIM LAGESON N0UR wrote _Thu Feb 28 13:07:27 EST 2019_ - I have never owned an amp before and recently put together a KPA500. All seems to be working well, but I have a few questions. I am using with a IC-7300. How important is the ALC cable? I notice it is not included in the Basic Cabling Diagram in the manual but is discussed later in the manual. If I were accidently to run 100 watts into the KPA500 will the PWRIN HI Hard Fault/STBY protect itself before any damage is done. Would ALC protect me from that? Is it standard procedure to keep the KPA500 in line when turned off and not in use? I see you may run up to 200 through the KPA500 in STBY. Is there any concerns or settings on radio when running full break in on CW? Thanks Jim-N0UR ml -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT: Astron linear PS regulation issues
The nice thing about those linear power supplies, though, was that you COULD repair them. 73, Scott K9MA On 2/26/2019 09:52, Phil Kane wrote: On 2/25/2019 6:36 PM, Kevin McQuiggin (SFU) wrote: Not to sound like some old codger, but perhaps designs aren’t as robust as they used to be. More marketplace incentive to replace rather than to repair. Then again, no longer having a workshop or good close-up visual acuity any more, replace is the most viable option for me. I'm not getting old - I AM old (first licensed in 1952 as a teenager).-- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT: Astron linear PS regulation issues
On 2/26/2019 07:37, Jim - N4ST wrote: (The meter lights have been gone so long, I forgot it had meter lights.) Speaking of meter lights: Those #47 bulbs never lasted long at 6 V, so I used to put a resistor in series with them. Nowadays, a white LED, rectifier, and a resistor would work fine, and you would never have to replace it again. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT: Astron linear PS regulation issues
That's interesting. About the only way I know that a linear supply can be noisy is if the regulator oscillates. That can easily happen. Most of them use emitter followers, which are often unstable driving a capacitive load. That's usually easy to fix by inserting a small inductance between the emitter of the transistor and the load. A few turns of the appropriate sized wire around a ferrite bead usually works. 73, Scott K9MA On 2/25/2019 18:57, William Rascher wrote: On Monday, February 25, 2019 4:26:40 PM CST Rose wrote: I've found instances of regulation failures caused by loose hardware. With the RS-35m Astron Linear PS I have issues with noise. I purchased the PS because everyone around me swears that they are great. Well, from my experience the Powerwerx SS-30DV is far cleaner, quieter, and fewer $$. I though the problem was something along the line of LED lighting, in my shack was generating the noise. When I used a battery for the PX3 & KX3 in my shack during a power outage the PX3 screen was so clear I was stunned.I have 3 different Astron linear PS and all are noisy. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] K3- To zero beat or not to zero beat
Another possibility is all those SDR's sitting in unheated sheds sending RBN spots. That, of course, would lead to more or less random frequency errors. 73, Scott K9MA On 2/21/2019 23:12, Mike Flowers wrote: Perhaps what we are seeing here is the cumulative error of the transceivers in the chain. The DX tunes the rig to 14023 and calls CQ, but their transceiver is just a bit off frequency for one reason or another, so they are really on 14022.95. The spotting station’s transceiver is also a bit off frequency, so when the DX is tuned in, the spotter’s rig shows 14023.1 - and that’s what gets spotted if the frequency is acquired as data from the rig. If the spot is generated by keyboard, then more errors are possible. So when you click the spot, you go to 14023.1 and are .15 off the DX frequency +\- whatever variable your rig might introduce. I don’t have the expectation that when in click on a spot that I will be exactly on the DX frequency. I just like to land in the general neighborhood! -- Mike Flowers, K6MKF, NCDXC - "It's about DX!" -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] To zero beat or not to zero beat
On 2/21/2019 23:45, F5vjc wrote: I wondered if someone (Mike W5JR) would mention the N1MM feature to randomise spots frequencies on the Bandmap so that you DONT call on Zero beat. I tried it, but I found it spread out the spots way too much, and could find a way to control the spread. Now I just offset the XIT 30 Hz or so. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KPA-1500 tuner question
If HiSWR AUTOTUNE is enabled, this would be the expected behavior. However, ATU switching at the start of transmission sometimes happens even with it disabled. Elecraft is working on the ATU firmware in relation to this issue. I noticed it some time ago. Even with the HiSWR AUTOTUNE turned off and AUXBUS frequency data from the K3, the ATU sometimes switches when transmission starts. I don't know quite what it sounds like on the other end, but I seem to get asked for repeats off when it happens. Although the K3 sends frequency data to the KPA1500 only once per second, that isn't the main problem, as the switching occurs even if tuning has stopped for longer than that. Stay tuned. 73, Scott K9MA On 2/21/2019 09:36, Jim Miller wrote: Things to check Could be bad aux cable. Is it from Elecraft? Do you have anything else connected to aux? Are you sure connectors are fully engaged? On Feb 21, 2019, at 10:21 AM, Walter J. Legowski wrote: I experienced the same thing, especially on 20M. The tuner is apparently ignoring some of the signals on the AUXBUS line. I put a scope on that line. I can see, some of the time, the amplifier responding to the signal with a "clunk" as the tuner relays adjust to the new segment. The rest of the time, I see the signal, but no response from the amp. If you attempt to transmit when the signal is ignored, you get chattering relays followed by "ATU Retune Complete" on the amp display. I took a photo of the signal trace and sent it to Support yesterday. They haven't gotten back to me yet. Walt, WA1KKM On 2/21/19 3:36 AM, Peter Dougherty wrote: Hi all, Something I noticed this past weekend in the contest about the KPA1500, especially on 80 and 160, where the internal tuner was needed on antennas that were above ~1.5:1 SWR. When I changed frequencies into a range that required retuning, I had to manually press the ATU control and initiate a tune sequence, or else when I was auto-sending CW my call would get cut off as the tuner set its needed values. Since I'd memorized the entire band(s) ahead of time, is there a way for the memorized tuning solutions to load on QSY, rather than on RF application? It really slowed me down as I was S my way through the low bands on Friday night. - 73 and Good DX Peter, W2IRT President, North Jersey DX Association DXCC Card Checker Letter O Manager, ARRL Incoming 2nd District QSL bureau -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] low pass filters
Hang on to that low pass filter! 73, Scott K9MA On 2/19/2019 10:55, Phil Kane wrote: On 2/18/2019 8:41 PM, K9MA wrote: Here, Don is talking about external low pass filters intended to suppress VHF harmonics. If you live in an area where TV signals are weak, they may still be necessary. Of course, hardly anyone receives their TV service that way any more, and most TV stations have moved to the UHF bands, anyway. Two assumptions that may not hold even in urban areas. Many cable / satellite subscribers are "cutting the cord" and going to over-the-air reception (I use that as a backup strategy when - not if - C*cast goes down), and because of the FCC's ill-regarded "repacking" scheme where UHF TV channels above 37 are being "re purposed" for the "broadband" industries' voracious need for spectrum, some urban TV stations are going back to their pre-UHF channels. With that said - I still use the "good old" external low-pass filter on my K2, rather than have it gather dust in the garage. Better be safe than sorry. 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] low pass filters
On Sun, Feb 17, 2019 at 4:26 PM Don Wilhelm wrote: Low pass filters come from a past era when the FCC requirements were not as stringent and TVs responded to those higher order harmonics from amateur transmitters. That is no longer the case. Here, Don is talking about external low pass filters intended to suppress VHF harmonics. If you live in an area where TV signals are weak, they may still be necessary. Of course, hardly anyone receives their TV service that way any more, and most TV stations have moved to the UHF bands, anyway. The low pass filters in solid state radios and amplifiers are necessary because their outputs are untuned, and the nonlinearity of transistors generates lots of harmonics, including low order ones. In the days of vacuum tubes, the pi network served as an effective filter. The popular pi-L was even better. It might be interesting, during a major contest, to listen on the second harmonic, say around 14.120 when there's a lot of activity on 40. Many are using solid state amplifiers now, and even 43 dB down may be audible. I've never positively identified one, but a lot of stations don't come back to me for other reasons, so it would be hard to tell. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Removing/connecting PL-259s
I use a single PL-259 for all the transmitting antennas as a lightning disconnect. I can attest to the fact that trouble ensues if I forget to tighten it with the pliers. I crashed my computer during the contest today. Twice, before I caught on. 73, Scott K9MA On 2/16/2019 21:40, Drew AF2Z wrote: No, a bit paranoid perhaps but I disconnect the rig entirely, including p/s cable. It's not too bad since I'm mostly a CW operator and don't usually have a lot of other peripherals, SDR, computer, etc. connected to the K3. BTW, I don't trust the Amphenol name particularly after getting a bad plug that wouldn't thread correctly (only realized after soldering the thing on the coax and trying to use it. Arggh!). Amphenol is offshore product now. 73, Drew AF2Z On 02/16/19 18:24, Don Wilhelm wrote: Drew and all, I have changed the subject line to something more akin to the current discussion. Have you considered adding a coax switch? Turning to switch to an open position (or better yet to a dummy load) when the radio is not in use will provide protection and is a lot easier than removing the connectors. 73, Don W3FPR On 2/16/2019 6:07 PM, Drew AF2Z wrote: FWIW, I use NO-OX-ID contact grease on my PL259 connectors. This allows very tight snugging by hand, no need of wrenching. During lightning season I frequently connect/disconnect my rig and tuner cables. The fine film of lube on the connector threads makes a big difference. Without it? A real PITA, not to mention wear and tear on the the SO-239's. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 vs SPE Amps
Based on my experience with the KPA1500, you shouldn't expect to run a solid state amplifier too close to it's rated output unless the SWR is pretty low, like better than 1.2:1. An ATU may or may not be able to keep the SWR that low. Otherwise, at a higher SWR, the amplifier output will sometimes drop to perhaps 2/3 the rated output, or the amplifier will fault due to high current or drive power. I expect the Expert 2K would have enough margin to put out 1.5 kW at higher SWR, but that extra margin comes at a cost. 73, Scott K9MA On 2/12/2019 15:44, Dave wrote: Has anyone had experience with both the KPA1500 and any of the current (1.3K, 1.5K or 2K) Expert Linears from SPE? I was initially leaning towards the 1.3K-FA without the ATU. The more I thought about it, the more I wanted to go with an ATU. The price difference to get less than 1db in going from 1300 watts to 1500 was also a bit of a concern. However, I’ve never pushed my 3x8874s to more than 1200 and only on the low bands. I have a KPA500 with the KAT500 and it’s great. However, in a 160 pileup a bit more power would help. Changing bands quickly is awesome. That has me leaning towards the KPA1500. If anyone would like to share their thoughts, it would be greatly appreciated. Also, I’m wondering if anyone has run their KPA500 and a KPA1500 off of the same K3? If so, how did you set it up? Tnx es 73, Dave N8AG Sent from Mail for Windows 10 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] KPA1500 ATU
Hi Ken, At the frequency of interest, the KPA1500 ATU goes right to bypass mode with a dummy load. 73, Scott K9MA On 2/6/2019 10:06, wa2...@gmail.com wrote: Scott, Did you try testing with a 50 ohm dummy load instead of an antenna? How goes it react? /Ken / /WA2LBI / /LG G6 / / / -- Original message-- *From: *K9MA *Date: *Wed, Feb 6, 2019 10:50 *To: *elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net>; *Cc: * *Subject:*[Elecraft] KPA1500 ATU Ever since I received my KPA1500 (SN 00178), I've observed that the ATU sometimes won't achieve a match better than about 1.4:1, even though the antenna SWR is well within range. (ATU STOP TUN SWR = 1.0:1, tune power 40 W) Now, 1.4:1 doesn't sound that high, but the amplifier will often not operate at full output at that SWR, either due to excessive current or drive power. This is particularly troublesome when tuning across a band. Clearly, the KPA1500 is designed to deliver 1500 W to a 50 Ohm load, with little margin for a mismatch. More margin would have increased cost, size, and weight, of course. Just to be sure there isn't something unique wrong with my KPA1500, have others observed similar behavior? A little ice on the antenna this morning provided an opportunity for a test. On 40 meters, the antenna SWR was 2.2:1. The best match the KPA1500 ATU could attain automatically was 1.4:1, in multiple attempts. I was able to manually get it down to 1.1:1. (SWR as indicated by the KPA1500 display.) It was a little tricky, requiring one value to be increased beyond the SWR minimum before the other was adjusted, as often happens with manual tuners. With the KPA1500 ATU bypassed, the K3 ATU automatically got it down to 1:1 on the first try. My conclusion is that there's something about the KPA1500 ATU algorithm that prevents it from achieving a better match, in some cases. (I'm assuming that, aside from their power ratings, the components in the KPA1500 ATU and the K3 ATU are similar.) I'm wondering if the KPA1500 ATU algorithm could be improved to perform more like that of the K3 ATU. That would allow operating the KPA1500 closer to full power across a band without having to ride the power control. Further details of ATU component values, etc. are available. 73, Scott K9MA -- Scott K9MA k...@sdellington.us _ -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KPA1500 ATU
Ever since I received my KPA1500 (SN 00178), I've observed that the ATU sometimes won't achieve a match better than about 1.4:1, even though the antenna SWR is well within range. (ATU STOP TUN SWR = 1.0:1, tune power 40 W) Now, 1.4:1 doesn't sound that high, but the amplifier will often not operate at full output at that SWR, either due to excessive current or drive power. This is particularly troublesome when tuning across a band. Clearly, the KPA1500 is designed to deliver 1500 W to a 50 Ohm load, with little margin for a mismatch. More margin would have increased cost, size, and weight, of course. Just to be sure there isn't something unique wrong with my KPA1500, have others observed similar behavior? A little ice on the antenna this morning provided an opportunity for a test. On 40 meters, the antenna SWR was 2.2:1. The best match the KPA1500 ATU could attain automatically was 1.4:1, in multiple attempts. I was able to manually get it down to 1.1:1. (SWR as indicated by the KPA1500 display.) It was a little tricky, requiring one value to be increased beyond the SWR minimum before the other was adjusted, as often happens with manual tuners. With the KPA1500 ATU bypassed, the K3 ATU automatically got it down to 1:1 on the first try. My conclusion is that there's something about the KPA1500 ATU algorithm that prevents it from achieving a better match, in some cases. (I'm assuming that, aside from their power ratings, the components in the KPA1500 ATU and the K3 ATU are similar.) I'm wondering if the KPA1500 ATU algorithm could be improved to perform more like that of the K3 ATU. That would allow operating the KPA1500 closer to full power across a band without having to ride the power control. Further details of ATU component values, etc. are available. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 KAT3 High SWR Issue Solved
On 1/23/2019 09:41, Ed G wrote: A fair amount of digging in the email archives found a couple posts which touched on an issue with the 8.215 MHz trap (C10 and L10) on the KAT3 tuner board. Although my older K3 doesn't seem to have a problem, I wonder why that trap was not required in the KAT3A. It was there, presumably to improve IF rejection, so I'd expect removing it without some other change to the K3 would be unwise. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?
There's undoubtedly a trade-off between rounder and longer. I was thinking of a typical more or less rectangular backpack, which would have a circumference much larger than a 12 inch circle. A typical backpacking pack could accommodate a circumference of about 88 inches, more than twice that of a 12 inch round loop. Granted, such a large pack wouldn't exactly be inconspicuous on an urban hiking trail, but you could always put some rocks in it, and pretend you're training for a Grand Canyon hike. 73, Scott K9MA On 1/22/2019 16:09, Grant Youngman wrote: Yes, it does not have to be round. The actual measurement of interest is Circumference of whatever shape it is (e.g, the total length of the radiator). A 12” loop or square, or whatever, is still going to have a very low efficiency at this size point. But closer to rounder is better … Grant NQ5T K3 #2091 KX3 #8342 On Jan 22, 2019, at 4:51 PM, K9MA <mailto:k...@sdellington.us>> wrote: On 1/22/2019 15:46, Grant Youngman wrote: The problem is loop diameter. It doesn't have to be round. 73, Scott K9MA -- -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?
On 1/22/2019 15:46, Grant Youngman wrote: The problem is loop diameter. It doesn't have to be round. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching
On 1/22/2019 14:14, Bob McGraw K4TAX wrote: Another trick which works well. Tune to a WWV frequency in CW mode. Press SPOT and the radio will jump on the exact carrier frequency. You can do the same thing, of course, by listening to the beat between the sidetone and the carrier. I was able to get 3 Hz closer that way, within the 1 Hz tuning resolution. 3 Hz is close enough, though. When listening for the beats, you have to match the volume of the sidetone and carrier, or you won't hear them. You don't need a musical ear, just a functioning one. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching
On 1/22/2019 10:59, David Gilbert wrote: Wayne, you forgot clicking on the DX Cluster spot. ;) Everyone zero beat was, I think, a bigger problem before skimmers. Skimmer spots often seem to be quite a ways off frequency, probably because their SDR receivers aren't all that stable. Some may be in unheated buildings, too. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching
Back in my college days at W9YT, we had a Drake line, separate transmitter and receivers. When searching and pouncing in a contest, you had to spot the transmitter before every contact. Spotting required turning one of the rotary switches on the transmitter, a cumbersome process. Imagine doing that a couple thousand times in a weekend. At some point, we came up with the idea to hook a foot switch up to do the spotting, which made it much easier, and save a lot of wear and tear on the rotary switch, not to mention the operator's wrist. In those days, 40-50 years ago, transceivers just didn't work well on CW, so almost all CW operators used separate transmitters and receivers. Some, like the Drake line, could transceive, but had the same problem on CW. Transceivers didn't account for the BFO offset, and there was no RIT or XIT. If you called another station in transceive mode, you would be 700 Hz or so off frequency. Two transceivers pretty much couldn't work each other at all. Sometime while I was inactive in the late 70's and 80's, that problem was solved, and we no longer had to spot before every contact. I think that solution had to wait for frequency synthesis, as it otherwise would have required additional (expensive) crystals. Does anyone know of a non-synthesized transceiver that didn't have the CW offset problem? 73, Scott K9MA On 1/21/2019 23:09, Wayne Burdick wrote: Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- are very useful tools for CW operators, especially those not experienced in pitch-matching. Here's a bit of history on where these features came from and how they work. -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] KX2 Bandwidth Issue
The KX2 (and maybe KX3) has long had an issue that when the filter bandwidth is set to x00 Hz, some artifacts appear. Over a year ago, a "temporary" fix was introduced, automatically adding 50 Hz to the x00, so it can only be set to 350, 450, etc. I know it's a minor thing, but I'm rather attached to using 400 Hz. Has anyone heard anything about a fix? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3s Line Out (stereo)
There's no mystery at all. The headphone outputs of two radios go to a switching system with a common ground. There inevitably is a small AC voltage difference between the chassis of the two radios, and from the radios to the rest of the system ground, which results in some current flowing in the headphone cable ground wires. Bonding everything together with braid might have helped, but it might have been hard to get the impedance low enough. The common ground was an oversight on my part, but avoiding it would have required third relay pole and isolated headphone jacks. Rather than rebuild the switching system, I inserted the transformers. They serve exactly the same purpose as the K3 internal ones in the line outputs. I'm not sure how other SO2R systems deal with the problem, but it has to be either isolation transformers of switched headphone grounds. Or, as does one of my friends, completely isolated left and right headphones. 73, Scott K9MA On 1/16/2019 09:36, Don Wilhelm wrote: The K3/K3S Line Out already has isolation transformers internal to the K3. I do not understand any need to put additional transformers in the audio path(s). What happens if you cable to LINE OUT signals to a computer soundcard (with both left and right channels - some only are one channel if the input is set for MIC)? You should hear the main RX in the left channel and the SubRX in the right. Your external transformers/cabling raises the question of "is it the K3S or is it your external devices that are causing the problem". Time to strip everything down to the essentials and begin to determine where the "failure" is occurring. Test one thing at a time. 73, Don W3FPR On 1/15/2019 8:00 PM, Dave Sublette wrote: My K3s arrived over the weekend and I have been setting it up. I am using the rear Audio jacks to drive either headphones, or the Line out to drive an amplifier and two speakers in the stereo mode. The headphone jack has stereo output ok. But the line out only has right channel audio. Left channel has nothing but a low hum. I am testing them one at a time, using the same cable. So it is not a case of a bad cable. The plug inserts to the same depth in both the headphone and line out jacks, so I believe the plug is properly inserted, I have been through both the Main Menu and Config menus, item by item. I see nothing that would give the option to turn off the left channel of the line out. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3s Line Out (stereo)
On 1/16/2019 10:00, Walter Underwood wrote: When I need to drive two sets of headphones, I use a $25 Behringer HA400 headphone distribution amp. https://www.amazon.com/Behringer-HA400-Ultra-Compact-4-Channel-Headphone/dp/B000KIPT30 Any trouble with RFI? 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3s Line Out (stereo)
The headphone outputs from my radios are switched with some relays. The switching system has a common ground, which creates a ground loop, resulting in 60 Hz hum in the headphones. (Call it common impedance coupling, if you prefer.) I should have isolated the headphone grounds, but a path of less resistance was to insert the isolation transformers. They are just common 600 Ohm transformers, like the ones in the K3 line outputs, but they're a bit lossy driving headphones. 73, Scott K9MA On 1/16/2019 09:02, Bob McGraw K4TAX wrote: I see no need for isolation transformers with headphones. Likely the transformers is the reason the HP output won't drive a pair of headphones. Isolation transformers? Are they 3 winding hybrid transformers? I've used them in professional audio installations but they are rare and expensive. 73 Bob, K4TAX On 1/15/2019 11:23 PM, K9MA wrote: I found that the level at headphone output, at least the rear panel one, was too low to drive two pairs of headphones in parallel in my setup, which includes some isolation transformers. The speaker output works fine with the headphones. (Don't try this with super sensitive low impedance headphones.) I just wired a switch to an external speaker. 73, Scott K9MA On 1/15/2019 20:51, Nr4c wrote: Why use Line Out for speakers. There is a perfectly good jack marked Speakers right next to the Phones jack. Be sure and use a Stereo plug but it is for wait for it. Speakers! -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3s Line Out (stereo)
My station has a relay system for switching the headphones between two different radios, among other things. I had to add isolation transformers for the same reason the K3 has them on the line outputs. The loss in the transformers reduces the audio level too much for the rear panel headphone jack to drive two sets of the low sensitivity headphones I use. And I don't want a cable in the way to the front panel. That's why it's "complicated". 73, Scott K9MA "Everything should be as simple as possible, but no simpler." -- Albert Einstein On 1/15/2019 23:38, Don Wilhelm wrote: Last Field Day, my K3 was used at the CW station. Two sets of headphones. One for the operator and one for the logger. One was plugged into the rear panel Phones jack and the other was plugged into the front panel jack. No problem, no splitter. Ok, if there were folks nearby who wanted to listen in, we would simply turn on SPKR+PHONES in the menu, and the speaker could also be heard. Very versatile. Why make it complicated - the K3 gives us the tools to do it 'the easy way'. 73, Don W3FPR On 1/15/2019 11:23 PM, K9MA wrote: I found that the level at headphone output, at least the rear panel one, was too low to drive two pairs of headphones in parallel in my setup, which includes some isolation transformers. The speaker output works fine with the headphones. (Don't try this with super sensitive low impedance headphones.) I just wired a switch to an external speaker. 73, Scott K9MA On 1/15/2019 20:51, Nr4c wrote: Why use Line Out for speakers. There is a perfectly good jack marked Speakers right next to the Phones jack. Be sure and use a Stereo plug but it is for wait for it. Speakers! __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3s Line Out (stereo)
I found that the level at headphone output, at least the rear panel one, was too low to drive two pairs of headphones in parallel in my setup, which includes some isolation transformers. The speaker output works fine with the headphones. (Don't try this with super sensitive low impedance headphones.) I just wired a switch to an external speaker. 73, Scott K9MA On 1/15/2019 20:51, Nr4c wrote: Why use Line Out for speakers. There is a perfectly good jack marked Speakers right next to the Phones jack. Be sure and use a Stereo plug but it is for wait for it. Speakers! -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Sub-receiver RIT
You have to integrate SO2V operation with the logging software. If you just switch VFO's, you have to switch back to run mode when you go back to the run frequency. Any small delay improves the chances you'll miss a contact or lose the frequency, so it has to be very fast. With the software I use, ctl-right arrow switches both tx and rx to VFO B, and moves to the VFO B logging window. Ctl-left arrow switches back to VFO A. There's no issue with using RIT when running on A and searching with B, but then the P3 can't be used to find new signals more than 10 kHz from the run frequency. Running on B solves that problem, but then there's no RIT when running. Actually, while RIT on the search and pounce VFO is most important, XIT is more useful when running. The ideal SO2V radio would allow RIT on B and XIT on A, automatically switching with the logging software. 73, Scott K9MA On 1/15/2019 16:04, Don Wilhelm wrote: Gernot, If you have the subRX, why not tune to listen for those off-frequency stations with the VFO B knob. Your transmit frequency is unchanged on VFO A, so no need for RIT unless you are only listening to the mainRX. An easy VFO A>B pushbutton will put VFO on the same frequency as VFO A anytime you change your transmit frequency. 73, Don W3FPR On 1/15/2019 4:29 PM, g...@gmx.net wrote: John, the issue with SO2V is that you want to stay on your run frequency, but be able to slightly tune up and down to hear callers which are not exactly on your TX freq. RIT comes in handy here, as you just press RIT or CLR after the QSO is finished. I don't have a K-POD, but if it would let me do this stuff I'd consider buying one. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Sub-receiver RIT
"Of course if you get too far away from your run frequency, you'll have to increase the P3 span so that you can still the VFO B cursor" Therein lies the problem: With the span set to more than 10 kHz, it's very hard to resolve CW signals on the P3. A VGA display would help, of course, but I'd rather not go that way. Anyhow, I'm hoping maybe just a little mod to the K3(s) firmware could provide a way to use RIT with VFO B. 73, Scott K9MA On 1/14/2019 23:58, Bob Wilson, N6TV wrote: On Sun, Jan 13, 2019 at 9:15 AM K9MA <mailto:k...@sdellington.us>> wrote: I've found that during some contest operation, it's handy to call CQ on VFO B, while using VFO A to search and pounce. (Known as Single Operator 2 VFO mode, SO2V.) That way, when unassisted, I can use the P3 to locate promising signals. However, I sometimes wish the RIT would work with the sub-receiver on VFO B. Has anyone found a way to do this? Even better would be to have RIT on VFO B and XIT on VFO A. When running SO2V unassisted, I find it easiest to do the opposite: CQ on VFO A, and S on VFO B. Then you can have the RIT on A and watch the VFO B cursor track VFO B. Of course if you get too far away from your run frequency, you'll have to increase the P3 span so that you can still the VFO B cursor, but this is the best way around this problem for now, without resorting to extra hardware. Of course assisted operators can just send a spot to VFO B to have a listen. 73, Bob, N6TV -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Sub-receiver RIT
On 1/14/2019 19:55, j...@kk9a.com wrote: Is the issue the way the P3 is used to move in on a signal? Yes, that is exactly the issue. When unassisted, using the P3 is the best method I've found for finding new contacts. However, the span has to be 10 kHz, or it's too hard to resolve cw signals. (I know, I could add a VGA display.) Other than the RIT issue, running on VFO B and the sub rx works well. If there were a setting, say, to make the RIT apply to VFO B only when the sub was on, the problem would be solved. 73, Scott K9MA -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] K3 Sub-receiver RIT
Thanks, Gernot. I came to the same conclusion. I also tried using "BSET", but it doesn't enable the RIT on VFO B. Maybe a firmware update could fix that? 73, Scott K9MA On 1/14/2019 19:01, g...@gmx.net wrote: Scott, I looked at the programmer ref manual and realized there is only one RIT/XIT, which is controlling VFO A. I guess there are two choices left: - either you press A/B to switch to your CQ VFO. - or you try to mimick RIT of VFO B via FBxxx; commands with the help of an external control knob. Maybe this feature can be added more easily to the K-POD? 73 Gernot DF5RF Am 13.01.2019 um 18:14 schrieb K9MA: I've found that during some contest operation, it's handy to call CQ on VFO B, while using VFO A to search and pounce. (Known as Single Operator 2 VFO mode, SO2V.) That way, when unassisted, I can use the P3 to locate promising signals. However, I sometimes wish the RIT would work with the sub-receiver on VFO B. Has anyone found a way to do this? Even better would be to have RIT on VFO B and XIT on VFO A. If it's not currently possible, I'd add it to my firmware wish list. 73, Scott K9MA __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to k...@sdellington.us -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] 500Hz Filter Offset Question
It looks to me like you still have to set the offsets. See manual. It doesn't appear there is any difference between the K3 and K3s as far as filter offsets. When I set up my K3, I tried to get the 200 Hz filter offset "just right", so the noise would sound exactly the same in USB or LSB (CW or CW REV). I found that the filter drifted around quite a bit with temperature. So, if you have the narrow filters, let the temperature stabilize before setting the offset. Wider filters are much less critical. 73, Scott K9MA On 1/14/2019 17:13, Nr4c wrote: Well they used to be difrentisted from the 8 pole filters haven’t looked for them on new site. Eight pole filters have a metal can enclosing them. The five pole filters are just exposed PC boards. I think I have offsets set on my K3S for the 200 Hz filters. Sent from my iPhone ...nr4c. bill On Jan 14, 2019, at 5:30 PM, Rich wrote: I just received my 500hz filters from Elecraft. I guess I assumed they were 8 pole, however they are 5 pole. The web page does not specify 5 or 8 pole, or I did not navigate the webpage properly. So now that I have 5 pole filters, I seem to recall that entering the offset freq is not required any longer on the K3S, is that true? Also does a K3 upgraded with K3S features need the offset freq? I should mention that they are all matched. Is there a graphic representation of these 5 pole filters available? Thanks Rich K3RWN -- Scott K9MA k...@sdellington.us __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
