Re: [Elecraft] KSYN3A INSTALL
Use a 5" or 6" TMP cable and hook it from J6 on the KREF3 (same as old synth) to either J83 or J1 on the KSYN3A. 73, Rich AC7MA On 06/12/2016 09:29 AM, Michael Murphy wrote: I am about to install a new synthesizer board in my K3. I do not have the 2nd rx or a 2 meter module. I am not clear on which connector(s) to hook the tmp connector(s) to. The instructions seem to be more geared toward installing it with the 2nd rx and/or the 2 meter module. What am I missing? __ 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 KXIO2 Power Consumption Q
Jim, About 30 uA with the radio off, and about 1 mA with it on. 73, Rich AC7MA On 06/07/2016 08:16 AM, Jim GM wrote: Hi Does the KXIO2 board Draw power with the radio turned off? If so how much does it draw off the battery? With the KX2 turned on how much is the KXIO2 power draw? Jim K9TF 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 ric...@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 arch...@mail-archive.com
Re: [Elecraft] kx3 internal batteries question
The KXBC3 checks battery voltage before starting a charge, and if it's not within a reasonable range (6.4V to 11.2V) it will indicate an error condition. Battery manufacturers recommend not discharging cells below 0.9V, and healthy cells will normally hold a residual charge pretty well without a load, so the error message was letting you know something was wrong. Sanyo (maker of the Eneloops) has historically been a top tier battery manufacturer, so they should work well in the KX3. 73, Rich AC7MA On 10/16/2013 02:01 PM, Richard Gagnon wrote: I have a question about the batteries in my KX3. I purchased and installed 8 Anasman 2850 NiMH batteries in the KX3 and have used the radio successfully on these batteries for several months, including several recharge cycles with the KX3 internal charger. I last used the KX3 several months ago, so the batteries were understandably dead when I went to try it out the other day. I plugged it in to an external wall wart (12VDC 1.5A) and turned the radio on. The reading on the screen was 12.0V. I then turned on the Battery Charger, but it would only give me a BATT ERROR on the screen. Thinking the wall wart might be the issue (it only supplied 12V and the manual says the charger voltage must be at least 13VDC) I plugged the KX3 into my bench supply at 13.5VDC and got the same BATT ERROR when turning on the internal charger. I then removed all 8 batteries and checked their voltage (no load, just with an old Simpson VOM) and 4 batteries measured 1.2 V and the other 4 were at 0.0 V. I am not sure why they would be different, nor do I understand the BATT ERROR message. I have since ordered 8 AA Eneloops XX low discharge 2500mAh batteries, and a Maha C9000 charger, but am curious as to how only have the batteries were dead on what might be going on with the BATT ERROR. Any thoughts or advise would be welcome. Thanks, Richard Gagnon KG1Y __ 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] KX3 12kHz audio spike
Nick, I think Lyle meant to type RX I/Q, not RX ISO. Turning on the RX I/Q outputs (which is accompanied by the DSP load leveling) will reduce the 12 kHz spur by 15 to 20 dB typically. Doing this also increases overall supply current by about 10 mA. When looking at these spurs on an audio spectrum analyzer that uses a very narrow resolution bandwidth, they're quite prominent. But they are at or below the noise in a 12 kHz (or greater) bandwidth. For quite a few of us we would never know they were there without the instrumentation. I guess good hearing can be a blessing or a curse, depending on what you're listening to... :-) 73, Rich AC7MA On 08/06/2013 07:41 AM, Nicklas Johnson wrote: Lyle: I gave setting RX ISO to ON a try, and though I can see some small changes in the spectrum analyzer, it doesn't seem to change the 12 kHz spike or its harmonics. Granted, my hearing is abnormally good for my age. I can still hear up to about 18 kHz, which is pretty unusual for an almost-38-year-old I'm told. Flyback transformers in old TVs and monitors are the worst thing in the world. I wonder if connecting a 100uF capacitor across the headphone output would be about right to attenuate noise above 5kHz. Johnny: I did this test by routing the headphone output of the KX3 into the input of a Roland Quad Capture, which is effectively just a really high-quality sound card, turned the gain on the Quad Capture up about halfway, and sampled the audio at 192kHz, 32-bit mono into Sound Forge. Then I ran Sound Forge's spectrum analysis tool on the captured audio. You could probably perform a similar test using an ordinary sound card to see whether you have the spike at 12kHz, but you might not see the ones at 24, 36, and 48kHz if your sound card won't sample above 48000 Hz or won't provide enough gain. Free tools like Audacity also provide spectrum analysis if you don't already have something like Sound Forge. Thanks for the input; it's nice to know at least that I'm not crazy ;-) 73, Nick On 6 August 2013 05:51, Lyle Johnson kk7p4...@gmail.com wrote: This is most likely power supply ripple from the variable loading of the DSP, which occurs at a 12 kHz rate. You may be able to reduce it by setting MENU:RX ISO to ON. This increases average current in part by preventing the DSP from sleeping between tasks, thus smoothing out some of the power supply load. It is always best to use headphones or external speakers that have limited response above 5 kHz with the KX3. The radio will not pass audio information above this frequency, so the only thing wide response headphones or speakers will provide is additional noise. This is particularly true if your ears haven't aged to provide some low-pass function for you :-) 73, Lyle KK7P While doing some tests tonight to compare the white noise of my Icom IC-7000 to the white noise of the KX3, both having the AF gain turned all the way down, I noticed... __**__**__ Elecraft mailing list Home: http://mailman.qth.net/**mailman/listinfo/elecrafthttp://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.**htmhttp://mailman.qth.net/mmfaq.htm Post: mailto:elecr...@mailman.qth.**net 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] KX3 AM-breakthrough
Hello Klaus, On 07/30/2013 02:20 AM, Klaus Dittrich wrote: ... I wonder why this isolation amplifier is off by default, but assume the reason is to save battery power which does not matter in case of use as home station. So I would like to know if there are any degradations in IP3 or more probable in opposite sideband suppression if this amplifier is permanent in the signal path because of additional phase shifts. As far as I remember this case is not included in the OSB adjustment procedure. It consumes about 10 to 15 mA, and when used at the 0 dB gain level (strictly for isolation) it degrades MDS slightly. If used at the 10 dB gain setting (10 dB preamp), it will improve MDS slightly. This circuit has a very high IP3 so it's affect on IMD3 dynamic range is mostly due to the change in MDS and signal gain to downstream circuits. This stage is before the signal is split into quadrature components, so it doesn't directly affect opposite sideband rejection. I was astonished to see during OSB adjustment how sensitve the procedure is to frequeny dependend phase shifts which I never thought they could be of importance. Every 10th mm on the circuit board and every ns in software seems to matter. Wayne, could you please drop a few words about this? Getting high levels of OSB rejection requires very precise phase and gain matching between the quadrature signal paths. 40 dB requires gain matching to be about 0.1 dB and phase matching to be about 1 degree. With precision components, 40 to 50 dB is about the practical limit of what can be done in hardware. The rest is done in DSP. Every 20 dB improvement requires about a 10x decrease in both phase and gain mismatch, so 80 dB of OSB rejection requires the phase balance to be about 0.01 degrees and the gain balance to be about 0.001 dB. It's possible to get a deep null during OSB calibration, but it takes very little change in the balance to move away from that point. 73, Rich AC7MA __ 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] Audio circuit distortion
That one reminds me of a story told some time back at one of our local QRP group meetings. One of the fellows once had a coworker who claimed the source of the power significantly affected audio quality, and that power from a hydro generator produced much cleaner sound than power from a natural gas power plant. Apparently the guy was dead serious. It took quite a while for the laughter to die down... 73, Rich AC7MA On 07/23/2013 02:47 PM, Ron D'Eau Claire wrote: And there are those who spend hundreds of dollars on a-c power cords for their audio systems that have been cryogenically treated to align the copper crystals to avoid turbulence in the a-c power flowing through the cord from the wall outlet. The problem is that human perception determines satisfaction, and perception is not always based on objective data. 73, Ron AC7AC -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Doug Person Sent: Tuesday, July 23, 2013 2:25 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Audio circuit distortion I once wired a guy's $20K audio system with RG8. He claimed it made all the difference. He also claimed that vinyl was vastly superior to CD's. I told him he had a wonderful imagination. The very best and cleanest vinyl with a radial tracking arm turntable and a top of the line cartridge could just barely make a 40db s/n. Digital audio can do 100db anytime. Many years of selling audio gear taught me about the psychology of hearing. It takes an experienced ear to appreciate a truly flat response. Most people prefer a very unbalanced equalization. I got lots of chuckles switching between a $300 system and a $3000 system and having most people prefer the cheap setup. Having designed loud speakers professionally (of which 1,000s were sold), I am equipped with very refined and experienced hearing. Unless you were listening to FM broadcast, how could you possibly appreciate a .3% THD? I always assumed anything less than 1% was more than adequate for our kind of communications. If we get down to this level of performance, we'll need to work on the 50% or so of stations that only concern themselves with output power - not audio quality. There is a lot of dreadfully distorted signals on 20 meter SSB. Nothing beats working a station that is s9+20 and barely understandable because he has compression and mic gain pushed up so he sees 1500 watts on his output meter all the time. So, IMHO, the K3 has absolutely splendid audio when I have a chance to work another station whose audio is actually adjusted correctly. It amazes me that most rigs today have a monitor function. Must be the most unused feature of all time. 73, Doug -- K0DXV __ 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] KX3 VFO B Alternate Display ?
Phil, That is correct. The battery '+' and external supply '+' are connected together. The voltage at the battery's negative terminal is measured and subtracted from the voltage at the '+' side. So with no batteries installed, 0V would be read at the batt '-' side. And when no external supply is connected, BT and PS will also read the same. This is all related to how the battery and external supply are isolated from each other through the diode 'OR-ing' circuit that allows the higher voltage of the two to power the radio. 73, Rich AC7MA On 07/15/2013 09:33 PM, Phil Hystad wrote: On the KX3 VFO B Alternate Display you read Time, Power Supply Voltage, Battery Voltage, and so forth. So, my question is regarding the BT (Battery Voltage) display. I assume that this reads the same as the external power supply voltage level (PS) if there are NO batteries in the battery holder. I never paid too much attention to this before and I have had batteries installed almost from the time I put the KX3 together so I have not noticed this before. So, can someone confirm that if no batteries are used that BT shows the same reading as PS? I can understand how this might make some sense but I think I would prefer that BT show zero volts (or, N/A) or something if no batteries are installed. Thanks 73, phil, K7PEH __ 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] KX3 VFO tuning noise reduced or eliminated
Mike, What you would be checking for is opposite sideband suppression and you'll need a very strong single tone signal source. S9 + 20 or thereabouts is a good level, and this can be on or around 20m. There's a procedure to do the calibration in the KXFL3 installation instructions, but the following is a fairly quick approach if you have a handy signal to use. - Turn AGC MD (menu) to OFF. Set AF gain to 1 before tuning to a strong signal. Set the PBT BW for 2 kHz, which should be FL1 setting. - Set mode to CW and check your PITCH setting. Multiply the pitch by 2 and set up RIT for minus this amount. For example, if PITCH is 550 Hz, set RIT to -1.10 kHz. Turn RIT OFF once it's set up. - Tune to the signal and adjust the preamp setting if needed to try and get the level to S9+10 or more. - Turn RIT on to hear the opposite sideband. The signal should be very weak and likely close to the noise floor. You'll also normally need to turn the AF gain way up to hear it. - Turn the AF gain back down then reduce the PBT BW so you get a change to FL2 and then again to FL3. The opposite sideband should be very weak for those settings as well. If it jumps up considerably, or if it's just not very weak for any of the BW settings, a calibration would be helpful. In that case, follow the procedure in the KXFL3 installation instructions. - Don't forget to turn AGC back on when done :-) 73, Rich AC7MA On 07/08/2013 10:12 AM, Mike WA8BXN wrote: The instructions suggest that realignment of the filter may be necessary if some of the capacitors are pressed on the board. Is there any simple way to tell if such realignment is necessary? Is it very likely that if those parts are not touched realignment is not needed? 73 - Mike WA8BXN __ 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] Source of NiMH cells?
Ken, If you primarily want to keep the clock alive, I think the 2000 mAH Sanyo Eneloop are hard to beat, based on cost, availability, and self discharge rate. I'd avoid Alkaline cells for long term use because of the potential damage from leaking. 73, Rich AC7MA On 06/27/2013 11:58 AM, Bob wrote: Hi Ken, While higher capacity may seem better, it is sort of a false promise. The highest capacity cells tend to have high self-discharge, which causes them to deplete just sitting on the shelf quickly. Look for low self-discharge batteries. Sanyo's Enerloop (~2000mah) or Sanyo's XX (~2500mah) are two good examples. Hard to beat amazon pricing. Enerloop are about $20 for a set of 8. XX are about $34. 73, Bob, WB4SON __ 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] KX3 and 2 Meters
Hello Steve, It sounds like the menu is set up for a 2m transverter. Go into the menu and find XV1 ON, and make sure the selection is 'no' (before making a change, you have to unlock it by holding RATE down for a few seconds). Hope this helps. 73, Rich AC7MA On 06/10/2013 01:08 PM, Steve wrote: I am the new owner of a slightly used (only on Sundays that didn't conflict with baseball or football, according to the previous owner) KX3 and just beginning to understand how it works. I am slowly reading each page of the operator's manual and checking each function of each knob and button so I can make contacts without messing up everything. I notice that 60 meter frequencies are not programmed and I will have to do that. One question I have, the answer to which I can't find anywhere in the operator's manual, is why 144.000 (fully tunable to 148.000) comes up after 6 meters if the module to do this has not been produced. Is this just there as a default and actually is an inoperative band for later use or . what?? Just wondering why this is not mentioned anywhere nor have I seen this question on the reflector (of course, with the tons of e-mails, I may have missed it. Tnx 73, Steve, N4EUK K2/100, KX3 __ 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] KX3: I/Q out on TRANSMIT?
Brian, The TX I/Q signals are only routed internally and aren't at any external connector, though they do have labeled test points. The I/Q connector on the side is an RX output only. 73, Rich AC7MA On 06/08/2013 04:49 AM, Brian Machesney wrote: I would like access to the I/Q signals produced by the DSP modulator on transmit. Are these signals available on the rig's I/Q outputs? Brian K1LI __ 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] KX3 and charging batteries (when, and why do they get hot?)
As the batteries discharge and reach the knee where voltage begins to drop off quickly, imbalances in capacity between the cells can lead to wider voltage differences between the individual cells. If discharge isn't stopped in time, it's also possible for the weakest cell to be subjected to a reverse charge. For example, 7 cells at 1.2V per cell is 8.4V. If there's an 8th cell in series, running the pack down to 8V would mean that the weak cell has -0.4V across it. This is a bit simplified and extreme, but the real goal is to not let an individual cell get below 0.9V, which is the typical manufacturer's spec for maximum discharge. Starting with 8 new, good quality batteries is the easiest way to get what should be a pretty well matched set, and picking a conservative voltage to stop at will help get maximum life from the batteries. As Mark points out, there really isn't much left near the end anyway. 73, Rich AC7MA One thing to be mindful of when setting the low battery warning, but particularly when On 06/06/2013 06:26 PM, Mark Petiford wrote: When should such batteries get charged, at what voltage level? Don't let them go below 1v per cell...about 8 volts total on the KX3 display...8.5V would be safer. Elecraft recommends setting the BAT MIN menu to 8.5 V (KX3 Owner's Manual Pg. 36) to give you some warning that you need to think about recharging. This is about 1.06V per cell. The KX3 will shut down at 8 V which is about 1V per cell, very near the absolute minimum for NiMH chemistry. There isn't much energy left below 1.06v per cell, so running them below that level really doesn't give you much extra operating time. Some folks set the BAT MIN to 9V to give them more warning and plenty of time to finish their QSO and shut the station down. __ 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] [KX3] Boost Buck 13.8 V Regulator
An LDO is also a simple option for a higher voltage pack. KX3 RX current decreases as voltage goes up due to the internal switching regulators, but minimum TX current at 10W out will likely be somewhere around 13V. The optimum between the two will probably be around 13.5V, so that would be a good place to set the LDO output. An LDO with very low drop is the MIC29502. Typical dropout voltage for 2A will be about 200mV, and at RX currents will be around 65mV. This low a drop really isn't necessary here though. But if the goal is to run the TX at 10W CW, the best power efficiency will occur with an external supply voltage ~11.8V (or the lowest voltage before rollback to 5W). So an efficient buck regulator set for about 11.8V ought to give the best battery life. The trade-off will be TX SSB IMD, where a higher voltage will help. 73, Rich AC7MA On 05/12/2013 11:38 PM, Glen Torr wrote: Hi All, I have a KX3 and am doing some SOTA activations. I have obtained a 4S LiPo battery which is somewhere north of 16 V with full charge. I would like to get a DC-DC regulator as a more elegany solution than series diodes. I have searched and searched but no solid outcomes. Anyone have any input on where to find such a regulator? Many Thanks, Glen __ 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] Kx3 lithium batteries life
Bob, I think you forgot to multiply by 24hrs/day for your annual energy consumption, but your conclusion is still valid. Even at a ~440 mAH for one year, the battery drain can be ignored for practical purposes. Most of the current is consumed by the shunt regulator and the resistor dividers on the +12V line. The LED does blink faintly as an 'alive' check when KX3 power is off, at a 1/2 second period. This is how often the microcontroller wakes up to check power status. Maybe an adventurous individual will put a scope across the resistor in series with the LED to measure average current, and the result may be surprising on how little it takes to produce a visible blink. 73, Rich AC7MA On 03/16/2013 11:07 AM, Bob wrote: Some earlier posts have referred to a LED on the charger/clock board that seems to blink 24/7. So there may be more load than just the clock on the internal battery. I haven't noticed anything glowing or blinking on mine. Still your message made me curious, so I measured the drain from the internal batteries (8 NiMH cells). With the radio turned off, it was about 50 microamps. This was surprising to me as clock chips usually pull much less than that (a factor of 30 less give or take). So I pulled out the schematics and found the KX3 uses a Microchip PIC24F16K101 as the time keeper and charge controller. The chip spec puts the real time clock drain at 350 nano amps, and says that the run mode currents should be 8 uA or so. Sure enough, there is a Yellow LED shown on the schematic (D2). But like I said, I don’t see it blinking on mine. Given the 50uA current draw I experienced, that is still only 18 mAH over an entire year. If you are talking 2800 mAH for a Energizer Ultimate Lithium, that is less than 1% of its capacity. So that can't explain the early demise of your batteries. You would expect those cells to say above 11 volts for almost their entire life, which would be about 12 hours of KX3 receive, and about 6 hours at with occasional transmit at 5 watts. Now you mentioned that you keep the radio powered by a external supply and really only use the Lithium batteries for time keeping. If that were the case then you would need to have an external supply that was always above about 12.4 volts to keep the Lithium batteries from partially discharging. 73, Bob, WB4SON __ 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] Kx3 lithium batteries life
Ken, The lithium batteries should be able to keep the clock going for quite a few years. When the KX3 is off, the KXBC3 current should be around 50 to 75 microamps, depending on battery voltage, which comes out to roughly 1.5 mAH per day. 73, Rich AC7MA On 03/15/2013 08:33 AM, kennet4...@aol.com wrote: I have had lithium batteries in my KX3 since I received it last Nov. I use the batteries only to keep the clock alive and have never used them to transmit or receive.. I use an external power supply to transmit etc, I now find that if I try to turn on the rig using just the batteries the rig comes on then immidiately turns itself off. I assume the batteries are to the point where there is not enough voltage to power up the rig but the B T voltage reads 10.5 to 11 volts which I thought should be enough to turn the rig on Does the clock in the KX3 take that much power that even lithium batteries have a very short life .?? Has anyone else experienced this situation?? Is there something I am missing ?? Ken K1DWZ __ 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] Fwd: KX3 Relay Control For Desktop Amplifiers
Jim, The FET shouldn't have had any problem with 50 mA. It's a 2N7002 and is rated for 115 mA continuous and 800 mA pulsed, with 60V max voltage when off. One possibility is that the load being switched was inductive (like a relay), and the FET's voltage rating was exceeded when the relay was released due to inductive kickback. The simplest solution to snub the kickback spike is to put a reverse diode, like a 1N4002, across the relay coil (cathode side to the relay's '+' supply). It's also possible the FET was defective or damaged to begin with, which led to an early failure. 73, Rich AC7MA On 03/12/2013 01:28 PM, jimk...@aol.com wrote: I blew the switching FET with about 50 ma of current (12 volts) from a DownEast Microwave transverter. Elecraft says it should have handled it, but anyway, FWIW. The FET has been replaced, and an intermediate switching transistor installed in the switchbox for the several transverters. Now switching 1 or 2 ma, hope that holds! 73 - Jim K8MR From: robertwschumac...@yahoo.com To: elecraft@mailman.qth.net Sent: 3/12/2013 12:07:26 P.M. Eastern Daylight Time Subj: [Elecraft] KX3 Relay Control For Desktop Amplifiers Most common desktop amps have a relay circuit that requires a transceiver to short 12 VDC at 100 ma to key the amplifier on. In the KX3 specs, the maximum amp relay current is stated to be 100 ma. Has anyone keyed a desktop amp directly with a KX3 or is it recommended to use an intermediate external relay circuit? Thanks, W9DBR __ 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] Fwd: KX3 Relay Control For Desktop Amplifiers
There's a drain-source diode, but it doesn't protect the 2N7002 in this configuration. Typical sink-to-ground relay driver circuits put a diode across the coil so it keeps the switched side of the relay from going way above the supply voltage when the relay is turned off. Rich AC7MA On 03/12/2013 05:01 PM, hawley, charles j jr wrote: The 2N7002 has an internal diode for any inductive collapse. Sent from my iPad Chuck, KE9UW (Jack for BMW motorcycles) On Mar 12, 2013, at 6:58 PM, Rich Heineck ric...@frontier.com wrote: Jim, The FET shouldn't have had any problem with 50 mA. It's a 2N7002 and is rated for 115 mA continuous and 800 mA pulsed, with 60V max voltage when off. One possibility is that the load being switched was inductive (like a relay), and the FET's voltage rating was exceeded when the relay was released due to inductive kickback. The simplest solution to snub the kickback spike is to put a reverse diode, like a 1N4002, across the relay coil (cathode side to the relay's '+' supply). It's also possible the FET was defective or damaged to begin with, which led to an early failure. 73, Rich AC7MA On 03/12/2013 01:28 PM, jimk...@aol.com wrote: I blew the switching FET with about 50 ma of current (12 volts) from a DownEast Microwave transverter. Elecraft says it should have handled it, but anyway, FWIW. The FET has been replaced, and an intermediate switching transistor installed in the switchbox for the several transverters. Now switching 1 or 2 ma, hope that holds! 73 - Jim K8MR From: robertwschumac...@yahoo.com To: elecraft@mailman.qth.net Sent: 3/12/2013 12:07:26 P.M. Eastern Daylight Time Subj: [Elecraft] KX3 Relay Control For Desktop Amplifiers Most common desktop amps have a relay circuit that requires a transceiver to short 12 VDC at 100 ma to key the amplifier on. In the KX3 specs, the maximum amp relay current is stated to be 100 ma. Has anyone keyed a desktop amp directly with a KX3 or is it recommended to use an intermediate external relay circuit? Thanks, W9DBR __ 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] KXBC3 behavior
Fred, Most likely the battery temperature got up to 45 degrees C and charging was suspended until they cooled to 40 C. Normally a message should appearwhen that happens. 73, Rich AC7MA On 02/01/2013 12:02 PM, Fred Carvalho wrote: Hi Folks. Sorry if this has been asked/explained before. I have installed the KXBC3 NiMH Battery Charger module. I am using 2300mh/h NiMH AA cells. I have plugged a bench power supply with voltage/amp meters so I can check what is going on. My cells were not empty, so I have chosen 4 hours charge. I set the PS to 14VDC. The PS amp meter reads 390mA during the charging, which is about 190mA for the rig RX drain plus 200mA for the batteries. So far so good. I monitor the elapsed time in the MENU/BAT CHG and the BAT voltage, which goes up to 11.7V. After 1 hour and so, the elapsed time chronometer stops. The PS amp meter reads only 190mA. So it seems that the charger stopped charging. That is in-line with the fact that the battery was somewhat charged. I go to MENU/BAT CHG and turn the charger OFF. I also unplug the power supply. The battery voltage drops to 11V on the screen. In any phase of the process I got no error message. Is this an expected behavior ? I have not seen anywhere an explanation of what happens if the battery is totally charged. Is the counter supposed to stop, or it should keep on sending charge to the battery until the total programmed time elapses?. Any input is appreciated. Thanks __ 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] KX3 Smarter Charger
During charge at 200mA, the NiMH batteries can typically reach 1.5V each, for 12V total. Add in the extra voltage for path resistance, isolation diode, and charging regulator overhead, you get up over 13.5V, which is why the recommended voltage is 13.8V. Charging at lower supply voltages would have required a switching boost regulator which then gets into problems of space, RFI, and cost. It is possible to put some charge into a depleted set of batteries from a lower supply voltage but they just won't be able to get fully charged. Because the battery holders will hold any kind of AA cell, we opted for safety and charge reliability when it came to selection of how the charger operates. With 8 NiMH cells in series, the influence of things like temperature, cell condition, and other factors make automatic detection of full charge at moderate charging currents unreliable. A timed charge may not be elegant, but it's the approach recommended by the major battery manufacturers when not doing a fast, smart charge. And the latter requires much higher current and was just not feasible in the KX3 due to safety, power requirements, heat, RFI, and a few other things. Hopefully this helps explain a bit why the charger operates as it does. 73, Rich AC7MA On 01/30/2013 10:33 AM, Alan Davenport wrote: Your questions are valid. I asked the same ones myself. I'm also disappointed in the charger. I also found that it is very fussy about input voltage. I run my 12v rigs in my shack off deep cycle marine batteries which I keep topped off with a high end marine smart charger (ironic!) When the smart charger shuts down because the batteries are topped off the charger in the KX3 refuses to charge its batteries while stating input voltage too low. There is nothing wrong with my shack batteries. This issue (input voltage too low) occurred even when the shack batteries were brand new. (I had replaced them all just prior to hurricane Sandy.) I'm sorry Elecraft. All your other gear it a grand slam home run. This charger is just a bloop single. 73 de Al, W2GZN From: kis...@me.com kis...@me.com To: elecraft@mailman.qth.net Sent: Tuesday, January 29, 2013 5:53 PM Subject: [Elecraft] KX3 Smarter Charger I don't claim to know about battery charging but why can't the charger stop when the batteries get to X volts and start charging when the total battery voltage drops below Y volts, would this feedback system add to the cost of the charger. I bought a smart charger at Harbor Freight for $5.99 the red light goes green when the batteries ( 4 NiMH) are fully charged and when you put depleted batteries in it it blinks red. Why can't the charger in the KX3 be totally transparent? load and forget. I found the whole charging instructions confusing after an initial 16 hour charge do I occasionally give it a 4 hour charge or what ? do I want a lot of hot batteries in there? K6CG __ 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] KXBC3 charging
The recommended 13.8V minimum is for the external supply, and does take into account the diode drop. 73, Rich AC7MA On 01/27/2013 03:42 PM, Ron D'Eau Claire wrote: Mine charges just fine from a 13.8 VDC supply. 73 Ron AC7AC -Original Message- Hi, I believe your PS reading is too low. The PS reading on the KX3 should be at least 13.8 volts. There is a polarity diode so your ext power supply should be 14+ volts. At least this what my KX3 needs to charge. 73 Jim H K7SSS __ 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] [KX3] 160-80 meter mod?
John, The 160/80 meter mod that improves IMD dynamic range requires replacing a total of four parts in the T/R switching and one of the BP filters. The mod would not be overly difficult for someone proficient with SMD rework but I wouldn't recommend it for someone who isn't. To answer your question, trying to break off the existing parts would most likely damage the board. The areas are also pretty dense, so soldering iron access is a bit tricky in a couple spots. 73, Rich AC7MA On 01/09/2013 06:12 AM, John Fritze wrote: Can anyone who has done the 160/80 meter LP filter mod tell me if there are parts now on the pads on the circuit board? If there are, did you just break them off (then clean up the pads) or heat them and remove them? __ 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] Broadcast band interference [KX3}]
Gary, As an alternative to using RX SHFT, you could try reducing gain in the RF section if you have the preamp on. Try preamp at the 10dB setting or preamp off. 73, Rich AC7MA On 01/09/2013 07:15 AM, Gary Auchard wrote: I posted a question concerning an issue with broadcast band interference on my KX3 and received several good replys. Here's more info on this issue.there is a local AM broadcast station about 8 miles away but that is not the one I'm hearing. It's sounding like a Shortwave AM broadcast from some religious station. Using the RX SHFT as suggested by one person replying is not a viable option. When you do that it disables the Roofing Filter option which I need usually for copying CW signals where I'm having the problem. I do have the antenna tuner installed and tuned to the band where I'm working but I'm still getting the problem. The signal does vary up and down in strength so I'm sure it's a Shortwave signal causing the problem. I can live with the problem most of the time but I would hope Elecraft could provide an answer to this issue. How about it Eric or Wayne? Any comments from your end? My KX3 is SN. 564 built by me in June of 2012. Gary A. - W0MNA __ 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] KXBC3 observations
On 12/15/2012 3:44 PM, Peter Lambert wrote: I charged the batteries again overnight. They were completely flat (8.2V) when I started the 16 hour charge cycle. About 2 hours before the cycle was due to finish the display showed not0-40C. The ambient temperature was 27C, the PA 33C and the OSC 42C. It's about an hour later now and the display still shows not0-40C. Another 15 minutes later and the charge cycle seems to have continued where it left off. I guess my question is where is the temperature sensor used by the battery charger ?. (ie is it on the KXBC3 board which would be quite close to the batteries and this over temp indication really means batteries are in fact fully charged and starting to self-heat or is using the OSC temp sensor perhaps ?). Hi Peter, The temperature sensor is on the KXBC3 board and has pretty good thermal coupling to the side contacting the batteries in about the middle of the pack. Charging will suspend when the temp hits 45 degrees C and will resume when it drops below 40 C. With the specific conditions you describe, it's pretty likely the batteries are fully charged (or very close) when you get the not0-40C message. 73, Rich AC7MA __ 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] Kx3 internal charger
Hi Adrian, There were some problems like this that had occurred once in a while, but should now be fixed with MCU firmware version 1.27 73, Rich AC7MA On 11/24/2012 1:41 PM, Adrian wrote: Hi all I have the internal charger option fitted now. I noticed when the radio is off you get the charging count down. But after a while the count down becomes gibberish. Just random mess. Any have this problem. Regards Adrian vk5zbr Sent from my iPhone __ 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] Sherwood receiver test on KX3
If operating CW, another approach that could be used to avoid a strong signal in the opposite sideband is to hold the MODE button to go into CW REV. Rich AC7MA On 8/14/2012 1:47 PM, webrehm wrote: The Sherwood test of the KX3 says this in the notes for the superscript V At 1 kHz performance is opposite sideband rejection limited. On CW consider switching to 8-kHz IF. Note: Roofing filter disabled in this mode. I do not see anything in the manual about the 8 Khz IF mode. It is my understanding that when the roofing filter is used, which is a low pass filter, that the IF is 0 Hz. When the roofing filter is bypassed (FIL1) does this mean that the IF is shifted up to 8 KHz? What is the IF of the IQ outputs? Can someone explain this to me because I am confused. tks Dennis -- View this message in context: http://elecraft.365791.n2.nabble.com/Sherwood-receiver-test-on-KX3-tp7561045.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 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] New K3EXREF results
Ed's description provides a good overview but I can add a couple things that might help fill in some details. There are two TCXO specs of general interest. One is absolute frequency accuracy relative to 49,380,000 Hz, and the other is stability or drift. The absolute accuracy of the TCXO will vary from one K3 to another and really isn't critical since it can be corrected for by setting the REF*CAL value. K3 firmware uses the REF*CAL frequency in calculating the VFO / synthesizer frequency. The K3EXREF uses the external 10MHz frequency reference to accurately measure the actual TCXO frequency, which is then used to automatically update REF*CAL. With a K3EXREF running, and watching REF*CAL change during K3 warmup, you are seeing the drift of the TCXO as its measured frequency gets updated. The TCXO output frequency is never controlled. A benefit of this approach is that there is no degradation to phase noise. 73, Rich AC7MA On 10/30/2011 10:34 AM, Edward R. Cole wrote: See my test results of the K3EXREF: http://www.kl7uw.com/K3EXREF.htm When installed and referenced to a good 10-MHz external source the TCXO will be periodically corrected in frequency to keep the K3 on frequency. The display on REF*CAL merely indicates the value the TCXO has been offset to keep the radio on frequency and is not the freq. error. You need to measure the RF frequency with an accurate freq. counter to measure that. I have a counter that is locked to a Rubidium good to +/- 5E-11 and the max error at 50-MHz was +2-Hz (2/50,000,000) The value displayed on REF*CAL will start at 49.380 and they shift over about 30-minutes as the TCXO heats and stabilizes. K3EXREF keeps the radio on freq throughout this warm-up. Without K3EXREF the radio would shift freq with the TCXO (within 1ppm = +/-1E-6). Before the K3EXREF was available you had the option to entering a fixed offset to correct frequency (which should be done after the TCXO has warmed up and stabilizes). The number displayed is a similar offset but now controlled periodically by the external reference source, keeping the K3 more accurate. 73, Ed - KL7UW, WD2XSH/45 == BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep 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 __ 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] 14.316 help!
14.318 Mhz has been widely used on PC motherboards going back to the original IBM PC-AT. That would be high on my list of suspicious sources. 73, Rich AC7MA On 4/24/2011 12:56 PM, Jim wrote: That tone has been there for years. As long as I remember. 73 de Ke4wy Jim Sent from my compound. On Apr 24, 2011, at 3:38 PM, Grant Youngmann...@tx.rr.com wrote: I've had a weak 'carrier' in this spot for years. Used to have to endure it for the Icom Net at 14.317 in the old days. No clue what it is. Grant/NQ5T Sent from my iPhone On Apr 24, 2011, at 2:29 PM, Fred Jensenk6...@foothill.net wrote: Mine is at 14317.00 and is moderately weak. I __ 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] 14.316 help!
I just checked, and it looks like even the original 8088 IBM PC had a 14.318 MHz oscillator on it. And it's also one of the ISA bus signals. Rich AC7MA On 4/24/2011 10:17 PM, Kevin Rock wrote: Which crystal frequency did they use on the IBM PCs before the AT came out? Kevin. KD5ONS On Sun, 24 Apr 2011 22:09:17 -0700, Rich Heineckric...@frontier.com wrote: 14.318 Mhz has been widely used on PC motherboards going back to the original IBM PC-AT. That would be high on my list of suspicious sources. 73, Rich AC7MA __ 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] K3EXREF and Trimble Thunderbolts
The K3EXREF uses the 10 MHz standard as it's time base to measure the K3's TCXO and passes an error value to the K3's MCU every few seconds. No TCXO frequency control takes place, thus no increase in phase noise. Frequency compensation is done in software by automatically updating the REF CAL function. A relatively simple mechanism but effective :) For my installation, I'm using a Thunderbolt, an $11 active antenna from Digi-Key, and a 30' run of RG-6, which works nicely with the F connector on the Tbolt. 73, Rich AC7MA On 4/5/2011 10:35 AM, Leigh L. Klotz Jr WA5ZNU wrote: ... The K3XREF product that Elecraft is developing is, to my understanding, an external disciplining interface for the TCXO in the K3. It's probably a frequency counter / microprocessor which reads the internal oscillator and the external 10 MHz reference, and when the internal oscillator doesn't produce the right number of cycles in 10 million of the external oscillator's cycles, it adjusts the voltage on the TCXO to bring it back into spec. But if you do this too often, you'll introduce phase noise into the K3 (think of it as FM-ing). Wayne N6KR has said it does this a few times a second an has achieved a trade off between accuracy and phase noise. (I presume he doesn't adjust during TX, for example.) I leave my K3 on most of the time, and I've found that it is seldom off more than +/- 3 Hz. But the K3XREF would let it off +/- 1Hz as soon as you turn it on, provided it's hooked up to your external reference. The actual received frequency is only valid for one mode and one filter, once you calibrate it, since when you shift modes or filters the offets of the various internal IF stages varies. (Keep that in mind if you use the K3 for the ARRL FMT.) Leigh/WA5ZNU -- View this message in context: http://elecraft.365791.n2.nabble.com/K3EXREF-and-Trimble-Thunderbolts-tp6242158p6243171.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 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] K3EXREF and Trimble Thunderbolts
Hello James, You are correct on #1 and #2, as long as the signal amplitude feeding the K3EXREF is in the range of +4 dBm to +16 dBm. The Thunderbolt 10 MHz output is typically +12dBm (about 2.5V p-p), for example. 73, Rich AC7MA On 4/5/2011 12:11 PM, James Sarte (K2QI) wrote: Hello group, It's been many months since I've posted here, much less actually done something new with my K3. This topic has however piqued my interest. Just so I understand fully, am I right in assuming then that the following is correct: 1. Any reference oscillator operating at 10 MHz would work with the K3XREF? 2. All that's needed for this to work is the K3XREF, updated firmware, an accurate 10 MHz clock/oscillator, and a BNC cable? 3. Trimble Thunderbolt seems to be a good, cheap product to try. Any others that are $100? What are the additional advantages of doing this other than knowing you've pretty much eliminated any frequency drift? 73 de James K2QI President UNARC/4U1UN On Tue, Apr 5, 2011 at 2:32 PM, Rich Heineckric...@frontier.com wrote: The K3EXREF uses the 10 MHz standard as it's time base to measure the K3's TCXO and passes an error value to the K3's MCU every few seconds. No TCXO frequency control takes place, thus no increase in phase noise. Frequency compensation is done in software by automatically updating the REF CAL function. A relatively simple mechanism but effective :) For my installation, I'm using a Thunderbolt, an $11 active antenna from Digi-Key, and a 30' run of RG-6, which works nicely with the F connector on the Tbolt. 73, Rich AC7MA On 4/5/2011 10:35 AM, Leigh L. Klotz Jr WA5ZNU wrote: ... The K3XREF product that Elecraft is developing is, to my understanding, an external disciplining interface for the TCXO in the K3. It's probably a frequency counter / microprocessor which reads the internal oscillator and the external 10 MHz reference, and when the internal oscillator doesn't produce the right number of cycles in 10 million of the external oscillator's cycles, it adjusts the voltage on the TCXO to bring it back into spec. But if you do this too often, you'll introduce phase noise into the K3 (think of it as FM-ing). Wayne N6KR has said it does this a few times a second an has achieved a trade off between accuracy and phase noise. (I presume he doesn't adjust during TX, for example.) I leave my K3 on most of the time, and I've found that it is seldom off more than +/- 3 Hz. But the K3XREF would let it off +/- 1Hz as soon as you turn it on, provided it's hooked up to your external reference. The actual received frequency is only valid for one mode and one filter, once you calibrate it, since when you shift modes or filters the offets of the various internal IF stages varies. (Keep that in mind if you use the K3 for the ARRL FMT.) Leigh/WA5ZNU __ 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
