Re: [Elecraft] K3 receiver desensing on CW during contest
Larry N8LP wrote on 24 Februay 2009, at 02:40. I think the days of receivers with xtal filters are numbered. High speed ADCs capable of 140dB dynamic range without xtal filtering are on the horizon. A 20-bit ADC with enough processing gain would do it. -- Larry, You could be right, given an adequate amount of RD funding and time. When the performance of a state of the art HF receiver using xtal filters will be surpassed by one digitizing at signal frequency is an open question I think.. The performance standard in terms of Spurious Free 3rd Order dynamic range vs. time set in recent years by real HF superhet receivers using xtal filters, as I know it to be, is: Year 3rd Order SFDR3rd Order SFDRFilter Noise @ 2 kHzIn Passband BW Figure 1993 110 db 95 db 400 Hz 8 db 2007 122 db approx115 db 500 Hz 7 db So don't put the old horse out to pasture just yet :-) Sorry to have digressed from the subject matter. 73, Geoff GM4ESD __ 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 receiver desensing on CW during contest
Let's see: 122 to 140dB: only 15% increase! a walk in the park... ; - ) David G3UNA Geoffrey Mackenzie-Kennedy gm4...@btinternet.com wrote: Larry N8LP wrote on 24 Februay 2009, at 02:40. I think the days of receivers with xtal filters are numbered. High speed ADCs capable of 140dB dynamic range without xtal filtering are on the horizon. A 20-bit ADC with enough processing gain would do it. -- Larry, You could be right, given an adequate amount of RD funding and time. When the performance of a state of the art HF receiver using xtal filters will be surpassed by one digitizing at signal frequency is an open question I think.. The performance standard in terms of Spurious Free 3rd Order dynamic range vs. time set in recent years by real HF superhet receivers using xtal filters, as I know it to be, is: Year 3rd Order SFDR3rd Order SFDRFilter Noise @ 2 kHzIn Passband BW Figure 1993 110 db 95 db 400 Hz 8 db 2007 122 db approx115 db 500 Hz 7 db So don't put the old horse out to pasture just yet :-) Sorry to have digressed from the subject matter. 73, Geoff GM4ESD __ 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] K3 F/S
Have two K3's, selling one. Have REDUCED price. Anyone interested Please reply off the list will give more details. 73 de KE4WY Jim __ 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] K2 for sale
I have a K2 for sale with the following modules fitted, KSB2 SSB adaptor kit, KNB1 noise blanker kit and K160 top band kit. The serial number is 04458 and it works well is in very good condition and has the latest firmware installed, complete with all documents and power lead. Please contact off list. Jim G4NWJ. __ 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 receiver desensing on CW during contest
Geoffrey Mackenzie-Kennedy wrote: Larry N8LP wrote on 24 Februay 2009, at 02:40. I think the days of receivers with xtal filters are numbered. So don't put the old horse out to pasture just yet :-) I recall Icom's President Mr. Inouye saying something similar to Larry's comment just after the IC-756PRO was introduced (~10 years ago). Then Icom added even more crystal filters to keep the 7600/7700/7800 in the performance ballpark with Orion...and then the K3. I bet he wishes he had never said that. 73, Bill -- View this message in context: http://n2.nabble.com/K3-receiver-desensing-on-CW-during-contest-tp2369819p2377525.html Sent from the Elecraft mailing list archive at 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] Elecraft K2s K3s in ARRL DX CW
It's interesting to see how many K2s and K3s are mentioned along with how well they did. Other comments make for fun and educational reading. For the 2009 ARRL DX CW: http://www.eskimo.com/~mwdink/3830/ARRL%20DX%20CW%20Soapbox%20Feb%2023%202009.txt For comments from all the major contests: http://www.eskimo.com/~mwdink/3830/ Brutal QRP competition this time around in the US/VE. Not too many DX QRPers worked by me this time, one at 4 watts, one at 5 watts and one at 10 watts (OK this is a real stretch) 73, Julius Fazekas N2WN Tennessee Contest Group http://www.k4ro.net/tcg/index.html Tennessee QSO Party http://www.tnqp.org/ Elecraft K2/100 #4455 Elecraft K3/100 #366 __ 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] Free Membership! Free Certificate!
wayne burdick wrote: BTW, I see QRP as fun activity, not as a lifestyle. I run 20-100 watts about half the time, and 5-10 watts the other. Same here. I appreciate having the 100W PA I got for my K3, but I still get the most pleasure from the contacts I make using 5W or less. For me, life's too short to join a pileup. :) - Julian, G4ILO. K2 #392 K3 #222. http://www.g4ilo.com/ G4ILO's Shack http://www.g4ilo.com/blog.html G4ILO's Bloghttp://www.g4ilo.com/kcomm.html KComm for Elecraft K2 and K3 -- View this message in context: http://n2.nabble.com/Free-Membership%21--Free-Certificate%21-tp2374680p2378257.html Sent from the Elecraft mailing list archive at 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] K2-100 price
Question: What's a fair price for a K2-100 which is loaded? Thanks in advance. Dave, W6AQ **A Good Credit Score is 700 or Above. See yours in just 2 easy steps! (http://pr.atwola.com/promoclk/100126575x1218822736x1201267884/aol?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D668072%26hmpgID %3D62%26bcd%3DfebemailfooterNO62) __ 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] Tutorial about Filters and AGC
On Mon, 23 Feb 2009 13:57:32 -0500, Steve Ellington wrote: Is this correct? If a cw signal falls within the DSP passband it should and will pump the AGC. If a CW signal falls outside the DSP passband it should not pump the DSP's AGC. The problem here is defining what the DSP's passband it. If a signal is just outside the audio range of the DSP (can't be heard) then I would consider it outside the DSP passband and it should not pump the AGC however this is never the case. I see moderate signals just slightly outside the audio passband that pump the AGC. This is partly what is confusing us. Signals that we can't hear pumping the AGC worry us. What we hear coming from the speaker doesn't match how the AGC is responding. If my WIDTH is set for 100hz and a signal is at 110hz, I won't hear him but my S-meter responds to him as well as my AGC desenses (reduces gain). All of this has nothing to do with the roofing filter. There are several HUGE gaps of understanding in this question, so I'm going to attempt to respond to this tutorially. First, the shape of the skirts. You seem to be viewing the response of a filter as if it were square -- that is, no skirts. When you build a filter for a bandwidth of 100 Hz, 100 Hz is the width between the -3dB points on the filter's response. Depending on the design of the filter (how many poles and how they are aligned), the response may be -20 dB at a 200 Hz width, -40 dB at 400 Hz width, and so on. The filter's cutoff may be sharper or narrower, depending on the design. To get a feel for how filters work, go to the Inrad website and poke around until you find graphs of the response of some of their filters. Inrad makes high quality after-market IF and roofing filters for a lot of ham receivers, including the roofing filters used in the K3. Second, the -3dB points of a 100 Hz filter are 50 Hz above and below the center of the filter. Third, let's say that the signal you're trying to copy is 50 uV and the interfering signal is 5 mV. That's 40 dB difference. To make those signals equal in level in your earphones, the filter must be 40 dB down at the frequency of the interfering signal. Many of the stronger signals on the band may be 60-100 dB stronger than the weak signals we're trying to copy. If one of them is within the passband of the roofing filter or the IF, the skirts of both filters come into play. A fourth issue is that the all the filters in a system act in cascade -- that is, the total response is the sum of the responses of each filter. Let's say you have a 400 Hz roofing filter installed and you set the DSP IF to 400 Hz. The roofer may be -3dB at 200 Hz off frequency, the DSP is -3dB at 200 Hz off frequency, so the cascaded response is -6dB at 200 Hz off frequency. At 400 Hz, if each filter had the same shape (unlikely) and was -20dB, the two in cascade would be -40 dB. In general, 8-pole filters have steeper skirts (that is, their response cuts off more sharply as you move off center) than 5-pole filters, so a 5-pole 200 Hz filter might have the same response 200 Hz off frequency as an 8-pole 400 Hz filter. All of these filter shape and cascading concepts apply whether the filter uses crystals or DSP. From outside the hardware box, the primary differences between them are their degrees of adjustability, how much signal it takes to make them non-linear, and what they do when they overload. One major reason for using a roofing filter is to protect the DSP filter from being overloaded by strong signals. The other major reason is the cascading it provides. Now, let's look at the AGC. I haven't taken the time to study design details of the K3's AGC, but from what Wayne and Lyle have posted here, I think I understand that there are two AGC functions, one in hardware and one in software, that sense signal levels at different points in the signal flow and control gain at different points in the signal flow. The AGC in hardware is not adjustable directly, but we CAN (and MUST) prevent it from pumping by not overdriving it. The AGC in software (that is, the last IF) is VERY adjustable from the CONFIG menu. Another way of looking at the problem is to understand that the AGC turns down the system gain if the signal at the output of the IF is too high. If we let the AGC do it, the AGC will pump on a strong signal that gets through the filter skirts. But we can prevent most, if not all, of that pumping by turning down the RF gain with the controls on the front panel of the radio -- that is, turning off the preamp and turning on the attenuator and turning down the RF gain controls. That's how W4ZV operates his radio, and it's how I operate mine. We're both quite happy with how our radios are working. 73, Jim Brown K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post:
[Elecraft] K2 For Sale
Selling brand new K2 Ser# 6671, with SSB ATU, Hand mic Gamma Power Supply. Professionally scoped aligned after construction, over $1400 invested, asking $1200. H. Michael Pierce KD8DVV __ 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 receiver desensing on CW during contest
Not today... but give it a couple years. There is a lot of RD being poured into this by a number of competing chip manufacturers. Even if the next batch of designs falls a little short, an all digital design with BDR close to the best conventional designs would probably enjoy a very substantial market. 73, Larry N8LP Alan Bloom wrote: On Mon, 2009-02-23 at 18:40, N8LP wrote: ... I think the days of receivers with xtal filters are numbered. High speed ADCs capable of 140dB dynamic range without xtal filtering are on the horizon. A 20-bit ADC with enough processing gain would do it. I don't think you'll find a 20-bit ADC with a high enough sample rate to digitize the 3-30 MHz HF band (i.e. 65-70 MHz or so). At least not at a reasonable cost. I believe the best suitable, reasonable-cost ADCs available these days are able to achieve a 500-Hz blocking dynamic range in the low 120's dB, maybe 15-20 dB worse than the K3. That's significantly better than the previous generation of ADCs could achieve, and no doubt someday we'll get even better parts that are good enough to challenge the traditional superhet/crystal filter architecture. But I don't believe we're close to that level of performance today. Another issue, of course, is spurious responses. I'm pretty sure that current ADCs don't have good enough spurious-free dynamic range to challenge a state-of-the-art receiver like the K3. Al N1AL __ 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] Tutorial about Filters and AGC
Now, let's look at the AGC. I haven't taken the time to study design details of the K3's AGC, but from what Wayne and Lyle have posted here, I think I understand that there are two AGC functions,... And that, I believe is the root issue on the matter. (1) What is the passband of the hardware AGC, and what is its dependency (i.e., filter selection); and (2) What is the passband of the DSP AGC, and what is its dependency (i.e., filter selection). Looking at the K3 block diagram, it appears the DSP is fed back to the IF amp -- meaning that the hardware and software form a loop and hardware and DSP AGC are not independent (although a portion of the DSP could still be independent and not shown on the diagram) Concerning DSP in either the hardware AGC loop and/or the DSP AGC loop, is the passband of either loop variable as a function of the DSP bandwidth setting? Or, is the DSP AGC passband fixed, irrespective of the DSP filter setting? My apologies if this has been covered in prior messages, but I have not yet been able to extract the answers to these questions. Tnx! Paul, W9AC __ 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 F/S((SOLD)))
K3 has sold. Thanks to all who replied. 73 de KE4WY Jim -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Sent: Tuesday, February 24, 2009 6:05 AM To: elecraft@mailman.qth.net Subject: [Elecraft] K3 F/S Have two K3's, selling one. Have REDUCED price. Anyone interested Please reply off the list will give more details. 73 de KE4WY Jim __ 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] K3 and Ameritron AL-811 amp
Planning on hooking up an old 811 to my new k3 100. Appreciate any tuning tips. Bill Wade Ai4PF __ 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] Power-surge!
To the Elecraft Crew, Many thanks for building into the K3 to sense when the AC power is not there and shut-off completely! I say this because earlier this morning here locally there was a PGE power outage. Initially the juice went off and then just a few mil-secs the power tried to come back on, which would mean there'd be a huge power surge to follow! I had my finger on the Astron-50m to switch the rig off but I did'nt have to really do that, in that the K3 sensed the power cut-off and shut down immediately. Everybody knows what power-surges can do to our solid-state rigs, and eventhough most of our power-distribution strips SUPPOSEDLY have protection against such occurrences I've found that NOT all of them are cracked up to what they advertise!!! Many thanks for saving our BABY! Jim/nn6ee S/N 2406 __ 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] Power-surge!
On Tue, 24 Feb 2009 13:02:58 -0800, JIM DAVIS wrote: Many thanks for saving our BABY! Several thoughts. First, the K3 is isolated from the AC line by whatever DC supply you are using with it. For many years, I've run the 12VDC powered equipment in my hamshack from a big battery that is float-charged from a regulated 10A supply. A poor man's UPS, with excellent surge protection -- ON THE POWER LINE. There is, however, another MAJOR issue. Voltage spikes are also coupled to the power system ground (green wire) by all those nasty MOVs in power strips and office equipment throughout your home, and they can significantly raise the voltage on the green wire if the spike is BIG. That can cause failures if something connected to one of those outlets and another ground has a pin 1 problem -- and like most ham rigs, the K3 has several pin 1 problems on the KIO3. 73, Jim Brown 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
Re: [Elecraft] K3 receiver desensing on CW during contest
I agree this is something amateur equipment manufacturers like Elecraft should be keeping their eye on. If Analog Devices or someone came out with an under-$100 ADC with performance close to the K3, then you could save a lot of money and complexity by going to a directly-sampled RF front end architecture. But a lot of brilliant engineers have been working for many years trying to optimize ADC design. I just really have my doubts that they are going to make a 15-20 dB breakthrough any time soon. Al N1AL On Tue, 2009-02-24 at 09:55, Larry Phipps wrote: Not today... but give it a couple years. There is a lot of RD being poured into this by a number of competing chip manufacturers. Even if the next batch of designs falls a little short, an all digital design with BDR close to the best conventional designs would probably enjoy a very substantial market. 73, Larry N8LP Alan Bloom wrote: On Mon, 2009-02-23 at 18:40, N8LP wrote: ... I think the days of receivers with xtal filters are numbered. High speed ADCs capable of 140dB dynamic range without xtal filtering are on the horizon. A 20-bit ADC with enough processing gain would do it. I don't think you'll find a 20-bit ADC with a high enough sample rate to digitize the 3-30 MHz HF band (i.e. 65-70 MHz or so). At least not at a reasonable cost. I believe the best suitable, reasonable-cost ADCs available these days are able to achieve a 500-Hz blocking dynamic range in the low 120's dB, maybe 15-20 dB worse than the K3. That's significantly better than the previous generation of ADCs could achieve, and no doubt someday we'll get even better parts that are good enough to challenge the traditional superhet/crystal filter architecture. But I don't believe we're close to that level of performance today. Another issue, of course, is spurious responses. I'm pretty sure that current ADCs don't have good enough spurious-free dynamic range to challenge a state-of-the-art receiver like the K3. Al N1AL __ 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] Request for Elecraft K3 Utility program
The Elecraft K3 Utility program, is a great thing to have and is handy as an extra pair of hands. It provides, not only the conduit to upload firmware and make changes in the K3 but it also has a really nice terminal program to display what the K3 has decoded. My request is for an addition in the Terminal section. If I had a chance to suggest an addition to this program, however, I would ask that the use of the Memory keys be available as a one click operation rather than two but to make that addition as an option. Now, one must click on the Memory button and then on the Transmit button when you want to actually send it. Often this is exactly how you want to use this feature, however, if an option was added (TX data immediately) to just click on the Memory button and it adds the memory data to the buffer and immediately transmits it, that would save a step and often times, this could be extra helpful. I also would hope it could be optional so the times where you want to have the message locked and loaded and ready to be sent at just the right time as it is now. Also the current way allows multiple messages to be combined in the buffer. This request is for an in addition to and not an in place of which, by the way is the same answer I gave my wife when I told her I was ordering a K3 and she asked, Which radio does it replace? A second request along the same line, is to have an Ooops button to clear the transmit buffer like the current Clear button which flushes the received buffer. Obviously, if the first request above was made (immediate TX on Memory button click) but not made optional, there would be no need for this second request. Personally, I'd like to see both options implemented. Still, the K3 Utility program is a super addition to K3 operation, just the way it is now. Thanks and 73, Jim - K5LAD It's so simple to be wise. Just think of something stupid to say and then don't say it. -- Sam Levenson = My Web Page - http://www.hayseed.net/~jpk5lad __ 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] Power-surge!
At least one manufacturer (Tripp-Lite / Isobar) advertises that if your equipment is damaged from a power surge when powered thru their device they will repair or replace it for free. I use their surge suppressors for my computers, and have never had a problem, although they tend to make a horrible bang! on those occasions when they are killing a surge. Also, I wrote up a small item for the Glowbugs list that concerns using Amperite thermal delay relays to automatically cut off power for 30 seconds or so when one of those one-second outages happens. Here is the gist of that post. You should be able to gleam sufficient information from the text to see what is happening, and how you could use the idea to your advantage. The original post was concerned about how to get around contact bounce with thermal delay relays, which open and close relatively slowly. A suitable delay relay is an Amperite 115NO30 (115 volt heater, normally open contacts, 30 second delay) which I believe is available from eBay or various surplus dealers, typical price: less than $20.00. The usual disclaimers apply. _ The solution to the contact chatter issue is to use the thermal relay to activate a conventional relay that has the same coil voltage as the thermal relay heater. Use a set of contacts on the conventional relay, in parallel with the thermal relay's NO contacts to latch the conventional relay closed. This has several advantages. If wired correctly, this allows the thermal relay to be de-powered almost immediately after closure, thus effectively preventing heater burnout from prolonged activation, and the delay relay is aways ready for another cycle, instead of having to wait for it to cool down. The same SPDT contact set that uses its normally-open side to latch the conventional relay can, from the normally-closed side, control heater power for the thermal relay. If you use a DPDT conventional relay, then the set of contacts not used for latching and controlling the thermal relay heater can be used to switch the actual power load, avoiding the problem of burning the contacts of the expensive (and increasingly rare) thermal relay. The latching relay will drop out instantly on power off, so the cycle always starts fresh on each power on, no matter how long (or how short) the off period has been. I use this basic circuit in most of my power control systems, including multiple-outlet AC boxes, typically with a 30-second or so delay. In the event of a momentary power outage, the latching relay drops out at once and makes sure that sensitive items (hard disks, high-voltage power supplies, etc.) have completely spun-down or discharged before being re-energized. Has saved me any number of problems, and with a little more thought, allows remote control of power to whatever item(s) are being activated. _ _ - Jim, KL7CC JIM DAVIS wrote: To the Elecraft Crew, Many thanks for building into the K3 to sense when the AC power is not there and shut-off completely! I say this because earlier this morning here locally there was a PGE power outage. Initially the juice went off and then just a few mil-secs the power tried to come back on, which would mean there'd be a huge power surge to follow! I had my finger on the Astron-50m to switch the rig off but I did'nt have to really do that, in that the K3 sensed the power cut-off and shut down immediately. Everybody knows what power-surges can do to our solid-state rigs, and eventhough most of our power-distribution strips SUPPOSEDLY have protection against such occurrences I've found that NOT all of them are cracked up to what they advertise!!! Many thanks for saving our BABY! Jim/nn6ee S/N 2406 __ 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] K3 receiver desensing on CW during contest
You may be right, Al. I think the improvements may be incremental, and distributed among various aspects of the design, not just the ADC. For instance, ultra-low jitter clock sources, faster FPGAs with improved IP cores, etc. I think most hams would be thrilled with an improvement to 130dB BDR, along with getting rid of phase distortion, ringing and other anomalies in the xtal filters and other analog components. Unless you live near a shortwave broadcast station, or have a high power ham nearby on the same band, you're not likely to need 130dB BDR anyway. Even in those cases, having 200dB BDR probably wouldn't help unless there is a LOT of improvement in transmitter spurious emissions, distortion and phase noise. The highest signals I have seen here, during Field Day when there were several stations operating within a few miles of me, were 120dB above the noise floor. Of course, it's very important not to use any more front end gain than necessary for the band/conditions. 73, Larry N8LP Alan Bloom wrote: I agree this is something amateur equipment manufacturers like Elecraft should be keeping their eye on. If Analog Devices or someone came out with an under-$100 ADC with performance close to the K3, then you could save a lot of money and complexity by going to a directly-sampled RF front end architecture. But a lot of brilliant engineers have been working for many years trying to optimize ADC design. I just really have my doubts that they are going to make a 15-20 dB breakthrough any time soon. Al N1AL On Tue, 2009-02-24 at 09:55, Larry Phipps wrote: Not today... but give it a couple years. There is a lot of RD being poured into this by a number of competing chip manufacturers. Even if the next batch of designs falls a little short, an all digital design with BDR close to the best conventional designs would probably enjoy a very substantial market. 73, Larry N8LP Alan Bloom wrote: On Mon, 2009-02-23 at 18:40, N8LP wrote: ... I think the days of receivers with xtal filters are numbered. High speed ADCs capable of 140dB dynamic range without xtal filtering are on the horizon. A 20-bit ADC with enough processing gain would do it. I don't think you'll find a 20-bit ADC with a high enough sample rate to digitize the 3-30 MHz HF band (i.e. 65-70 MHz or so). At least not at a reasonable cost. I believe the best suitable, reasonable-cost ADCs available these days are able to achieve a 500-Hz blocking dynamic range in the low 120's dB, maybe 15-20 dB worse than the K3. That's significantly better than the previous generation of ADCs could achieve, and no doubt someday we'll get even better parts that are good enough to challenge the traditional superhet/crystal filter architecture. But I don't believe we're close to that level of performance today. Another issue, of course, is spurious responses. I'm pretty sure that current ADCs don't have good enough spurious-free dynamic range to challenge a state-of-the-art receiver like the K3. Al N1AL __ 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 -- View this message in context: http://n2.nabble.com/K3-receiver-desensing-on-CW-during-contest-tp2369819p2381481.html Sent from the Elecraft mailing list archive at 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
Re: [Elecraft] K3 and Ameritron AL-811 amp
I use my K3 with an Al-811 and it works just fine. I had the amp before the K3 so I already had my settings for load and plate recorded. Just use the settings in the 811 manual as a starting point and tune to what works best for you then record those settings. I have replaced the original tubes with Chinese 572B tubes. No more power but they are a more rugged tube so I just tune for max power out. With the 811s you will want to limit tune time but once there they should be fine. 73, Bill NZ0T bill wade wrote: Planning on hooking up an old 811 to my new k3 100. Appreciate any tuning tips. Bill Wade Ai4PF __ 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 -- View this message in context: http://n2.nabble.com/K3-and-Ameritron-AL-811-amp-tp2380034p2381502.html Sent from the Elecraft mailing list archive at 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
Re: [Elecraft] K3 receiver desensing on CW during contest
At the W1KM contesting site, we routinely see signals of +5 dBm or louder on/near 40m from SWBC stations (using a single Yagi). We also have two modest-power local AM stations (1 to 5 kW, a few miles away) just below 1500 kHz that show up even a bit stronger than that on our 160m antennas. Without taking into consideration signals from our own multi-multi transmitters, a receiver is already faced with 130 dB range between weak signals on 160m in mid-afternoon arriving from Europe and these other signal sources. WD3Q, a contester in Washington DC, has much stronger AM BC stations to deal with, including a 50 kW station on 1500 kHz. Wide-open receiver front ends attached to an A/D converter are not yet viable for these locations. -- Eric K3NA on 09 Feb 24 20:44 N8LP said the following: You may be right, Al. I think the improvements may be incremental, and distributed among various aspects of the design, not just the ADC. For instance, ultra-low jitter clock sources, faster FPGAs with improved IP cores, etc. I think most hams would be thrilled with an improvement to 130dB BDR, along with getting rid of phase distortion, ringing and other anomalies in the xtal filters and other analog components. Unless you live near a shortwave broadcast station, or have a high power ham nearby on the same band, you're not likely to need 130dB BDR anyway. Even in those cases, having 200dB BDR probably wouldn't help unless there is a LOT of improvement in transmitter spurious emissions, distortion and phase noise. The highest signals I have seen here, during Field Day when there were several stations operating within a few miles of me, were 120dB above the noise floor. Of course, it's very important not to use any more front end gain than necessary for the band/conditions. 73, Larry N8LP __ 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] K3 SN 2745 kit
It appears that all the mods should be included in this kit. I ordered it last week. The KIO board does not have any jumpers across the chokes. Has this board been reworked so there would be no jumpers and would this hold true for the mod kit KIO Digital board that I just got in for my other K3? A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin __ 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] 5 KHZ dead spots
Have noticed this on other bands but paid no particular attention, but today was tuning 160 meters and every 5 khz there is a pop or change in background receiver noise when tuning. I listened carefully and it is there tuning up freq or down. It is at every 5 khz. I can hear it at 1809.1, 1814.1, 1819.1, 1824.1 etc. sounds like some older rigs that when you have the tuner engaged it tunes every so often as you tune across the band. Like a pop or dead spot and as you pass the background noise changes a little. No tuner installed so its not that. Just curious if anyone hears it, takes a quiet band but its there. Background noise is higher pitch on the low side, and lower pitch on the high side of the pop. Internal or external by some chance? Merv KH7C __ 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] 5 KHZ dead spots
It is a K3. I am not seeing this on my unit. I even tried it with the ATU. A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Tuesday, February 24, 2009 9:58 PM To: Merv Schweigert Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] 5 KHZ dead spots Merv, Is this a 2 or a K3? If it is a K2, re-run the CAL PLL routine again. 73, Don W3FPR Merv Schweigert wrote: Have noticed this on other bands but paid no particular attention, but today was tuning 160 meters and every 5 khz there is a pop or change in background receiver noise when tuning. I listened carefully and it is there tuning up freq or down. It is at every 5 khz. I can hear it at 1809.1, 1814.1, 1819.1, 1824.1 etc. sounds like some older rigs that when you have the tuner engaged it tunes every so often as you tune across the band. Like a pop or dead spot and as you pass the background noise changes a little. No tuner installed so its not that. Just curious if anyone hears it, takes a quiet band but its there. Background noise is higher pitch on the low side, and lower pitch on the high side of the pop. Internal or external by some chance? Merv KH7C __ 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 -- -- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.237 / Virus Database: 270.11.3/1969 - Release Date: 02/24/09 06:43:00 __ 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] 5 KHZ dead spots
Merv Schweigert wrote: Have noticed this on other bands but paid no particular attention, but today was tuning 160 meters and every 5 khz there is a pop or change in background receiver noise when tuning. Hi Merv, This is normal. The K3 has an incredibly low-noise analog/digital synthesizer. To achieve this performance, we have to use a fairly low-frequency PLL loop (~22 kHz). This translates into a little artifact in the VFO tuning range every 22 kHz, on average, across the ham bands. Nearly all other PLL-based rigs have such transitions at much wider spacing, because they use up-conversion to a VHF 1st IF and thus much higher synthesizer output frequencies. But this results in inferior performance, generally, and doesn't support narrow roofing filters. (For example, most rigs on the market have a roofing filter in the 4 to 15 kHz wide range, compared to as low as 200 Hz in the K3. Our down-conversion scheme, to an 8.215 MHz IF, is the reason we can do this.) The tuning artifact is only noticeable if a moderate to strong signal is in the passband as you tune across it. When you stop tuning, it's gone. And while you're tuning, we do a partial mute of the receiver (actually, we engage a low-threshold limiter for about 10 ms). This makes it barely noticeable in most cases, which is why, with nearly 3000 K3s shipped, you've never heard a description of it until now :) The actual spacing of the tuning artifacts varies on a per-band basis, being smaller on the lower bands. The reason for this is a bit complicated. We shoe-horn the reference signal for the PLL (i.e. the DDS, the source of fine-tuning steps) through a 2.5 kHz crystal filter to ensure there are no DDS spurs in the VCO output. 2.5 kHz is a lot narrower than 22 kHz. So we have to constantly adjust the PLL divider values (N and R dividers, to be precise) so that our DDS signal always stays within the crystal filter, yet allows the PLL to generate a wide enough frequency range to cover the segment of interest. We used a home-brew PC program to pre-calculate the optimal N and R divider values for the entire tuning range, and we store them in about 30 kb of the front panel flash memory chip. As you tune the VFO, we look up the table values. This works smoothly, but as you noted, you might hear a soft blip under just the right circumstances as you cross one of the transition points. It's a little reminder of what it takes to create a very quiet, high-dynamic-range RX. 73, Wayne N6KR --- http://www.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
[Elecraft] Cross mode split not working.
Working AM on VFO A and setting up VFO B to receive SSB then operating the split it tells me SPT N/A. It used to work before installing v2.82, but it doesn't now which is a real nuisance as I have to manually switch between the VFO's if I want to transmit on AM and listen SSB. Is anyone else getting this? Thanks Paul. -- View this message in context: http://n2.nabble.com/Cross-mode-split-not-working.-tp2382176p2382176.html Sent from the Elecraft mailing list archive at 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
Re: [Elecraft] Cross mode split not working.
G4LNA wrote: Working AM on VFO A and setting up VFO B to receive SSB then operating the split it tells me SPT N/A. Hi Paul, I'm sorry to report that only a few modes are presently allowed for cross-mode split (CW/SSB, LSB/USB, CW/CW REV). Our goal is to add other modes back in if there's enough interest. Each requires considerable firmware modification and re-testing. Is AM/SSB a common split? Note that you can achieve this without using SPLIT if you have the sub-receiver installed. For example, you could transmit/receive in SSB mode on VFO A on one frequency, and receive AM on the sub on a different frequency. If you want to hear only AM signals, adjust the main and sub volume levels accordingly. 73, Wayne N6KR --- http://www.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
Re: [Elecraft] K3 SN 2745 kit
On Feb 24, 2009, at 7:53 PM, W0MU Mike Fatchett wrote: It appears that all the mods should be included in this kit. I ordered it last week. The KIO board does not have any jumpers across the chokes. Has this board been reworked so there would be no jumpers I'm pretty sure this is the case. If you want to be 100% certain, check the revision on the PCB and run it by Lyle, who designed this board. and would this hold true for the mod kit KIO Digital board that I just got in for my other K3? I'm not clear what you're asking. If ordered a replacement KIO3 board, it may indeed have the mods already. If you ordered a mod kit for an existing board, yet that board is already at the newest rev, you won't need it. 73, Wayne N6KR --- http://www.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
Re: [Elecraft] K3: AFX Firmware request
Yet it makes so much sense with the UI. DATA MD has no functionality when in CW and when holding NB or NR or the Notch filter or the like it allows you to configure the settable features of that feature. Granted its a slight UI breach but the product is still labeled as such on the button. I see this as a lesser evil to some of the press 1 while in this menu things which would have been more intuitive and fitting of the UI had they had their own menu item. But thats all just my opinion. ;) ~Brett PS: When I stated that I wouldn't put it past you I meant that as a compliment. Hopefully it was taken that way... At times text can very poorly portray a message. On Mon, 2009-02-23 at 18:45 -0800, wayne burdick wrote: Brett Howard wrote: Many of the buttons do different stuff based on what mode you're in. I'd not put something like this past him in the least. Brett, I'm cautiously flexible (and hopefully, consistent) with the controls. But I would never engage in a breech of UI etiquette as flagrant as making the DATA MD switch act as a shortcut to the AFX menu entry. One of our field testers proposed that over a year ago, and he couldn't talk me into it, either :) You *can* use a programmable switch function (PFx/Mx) for this, though. 73, Wayne N6KR --- http://www.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
