Don, As usual, you are right! I am in your debt.
What can I say? My apologies for taking up bandwidth on the reflector. You are correct, the K2 has only 2 decimal digits, and yes my drift is only 70 Hz. I am downstairs with my laptop and my memory is imperfect, the K2 is upstairs where I can't see it. Now that you have corrected me, I recall (after it is too late) that you have given my this advice before. I owe you an apology! Please forgive me. BTW, thanks for helping me many times over the years; you did not deserve this sort of discussion. TR, K6GC K2/100 S/N 838 At 10:22 PM 9/4/2011 -0400, Don Wilhelm wrote: >TR, > >What are you measuring the drift with? The K2 dial shows only 2 >decimal digits, so you can only read 7000.00 and not 7000.004 on the display. > >Drifting from 10000.004 to 9999.997 is only 7 Hz drift, and well >within the K2 specifications. >If you really mean 70 Hz drift (and you have inserted an extra zero >after the decimal), then please provide that correction. Even 70 Hz >is within the cold start spec for the K2. > >In addition, you are starting from a cold start - the K2 >specification is for less than 100 Hz from a cold start, so if your >cold start drift is actually 70 Hz, it is well within spec. >After warmup, the spec drift should be less than 30 Hz. to be within >spec. Most are more stable than that. The 1/4 watt resistor on the >Thermistor board can be altered to tighten this drift spec, but it >takes some experimentation. I would not recommend trying to alter >the resistor to reduce the cold start drift because that could >result in the normal operating drift to be worse. > >Please let your K2 warm up for at least 5 minutes and re-check the >drift with respect to WWV (choose the interval that you want to use >for the test, and do at least 3 samples over time and average them). > >It would seem that the original poster in this thread had a problem >different than drift. > >73, >Don W3FPR > >On 9/4/2011 9:24 PM, wreese wrote: >>Don, >> >>This is my problem. I have 120Hz drift. I have been unable to >>correct it and I sent my K2 to you and others without results. Let >>me give you an example. >> >>I come into the shack in the morning, it is about 65 degrees. I turn >>on the rig. The display says 7000.004 Khz. I hit the band button and >>shift to 10Mhz WWV. I hit the "zero beat" button and it gives me a >>matching tone. I zero the main tuning knob, and it verifies that WWV >>reads out at 10000.004 Khz >> >>Now, I do nothing. >> >>I go back to 7000.004 Khz and I tune around the band looking for a >>CQ. If I don't find one in about 1/2 hour I go back to 10Mhz >>WWV. It now zeros at -3Hz ie. 9999.997 Khz. >> >>I adjust the zero on 40 meters to read 6999.997 KHz. >> >>Now I get lucky. I find a CQ, I crank up the power to 100 Watts and >>I call him. I'm not fooling around, we do a real rag chew and we >>talk for perhaps 30 minutes. As I notice him drifting, and my >>experience tells me that it isn't him drifting, it's me, I use the >>tone zero beat and I adjust the main tuning knob to maintain zero >>beat with my QSO. He stops drifting when my dial reads 7043.993 >>KHz. Now the QSO ends and my K2 has stabilized. I return to 10MHz >>WWV and my dial reads 9999.993 KHz. >> >>Thanks, >> >>K6GC, TR >>K2/100 S/N 838 >>________________ >> >>At 05:07 PM 9/4/2011 -0400, Don Wilhelm wrote: >>>John, >>> >>>You are reporting a shift of 128 Hz in one case, and 117 Hz in another >>>case. The difference between the two is close to 20 Hz which is the K2 >>>BFO DAC limit, so that is not surprising, particularly if the BFO >>>voltage to the DAC is right on the "edge". >>> >>>Yet, I do not understand what approximately 120 Hz has to do with CW or >>>CWr - unless you have the K2 sitting close to an AC transformer, sine >>>120 Hz is twice the 60 Hz line frequency and the shift is coming from >>>the VFO. >>> >>>You may have some inconsistency in addressing the EEPROM. If that is >>>the case, it will be cured by a Master Reset - BUT record all your menu >>>settings before doing the reset and restore them afterwards. The K2 A >>>to B Instructions contain nice tables for recording the menu values, and >>>I encourage you to download those instructions to record the menu >>>parameters. >>> >>>I would suggest you use the N6KR method to set the 4 MHz reference - the >>>precise setting may be slightly different than exactly 4 MHz, and the >>>N6KR method erases any variables other than your ability to tune WWV (or >>>any other "standard" station) with precision in SSB mode. >>>For the full K2 Dial Calibration procedure, see the article dealing with >>>that subject on my website www.w3fpr.com. If you only want to set the 4 >>>MHz reference using the N6KR method and then run CAL PLL and CAL FIL, >>>you can refer to Wayne's document from the Elecraft reflector archives >>>of 8/20/03. >>> >>>Remember, setting the 4 MHz Reference Oscillator by itself does nothing >>>to the dial calibration, one must run CAL PLL and CAL FIL to set the new >>>values (based on the new setting of the Reference) into EEPROM before >>>any chance in tuning is made. >>> >>>73, >>>Don W3FPR >>> >>>On 9/3/2011 9:24 AM, John Oppenheimer wrote: >>>>I am a new K2 (#7212) user. I have been baffled by what I thought was my >>>>inability to properly perform the frequency alignments. My last attempt >>>>was to perform a factory reset and re-do PLL and BFO (Table 8-1 values) >>>>calibrations. >>>> >>>>I believe that I have found the issue, sometimes it appears that the VFO >>>>frequency offset look-up tables are not used and a toggle through two >>>>"CW REV" changes are needed. >>>> >>>>Used a K3 CWT SPOT as a 4MHz monitor to adjust C22. >>>> >>>>Using a K3, CWT, SPOT and K2 in in TUNE (with dummy load) to measure the >>>>K2's frequency. Test process is: >>>> >>>>Note: only the events in the below text were performed. >>>> >>>>Power off K2 with F set to 7026.00 >>>>Power on: K2 F=7026.00 K3 F = 7026.146 >>>>"CW REV" "CW REV", K3 F = 7026.018 >>>>Power off K2 >>>>Power on K2 F=7026.00, K3 F = 7026.025 >>>>Power off K2 >>>>Power on K2, Move K2 F to 7027.00, K3 F = 2027.028 >>>>Power off K2 >>>>Power on K2 F = 7027.00, K3 F = 2027.145 >>>>"CW REV" "CW REV", K3 F = 7027.000 >>>> >>>>I was listening to the audio during the above process. There was a >>>>notable change in the resulting pass-band audio when the "CW REV" "CW >>>>REV" toggle was performed and the K2 frequency changed. Leading me to >>>>believe that the VFO offset frequency was changed. >>>> >>>>Though I can't find a reproducible process, I have found events where >>>>during a K2 power on session, sometimes a "CW REV" "CW REV" is needed to >>>>acquire correct K2 frequency. >>>> >>>>Is this normal K2 operation, or do I have an issue with this K2? >>>> >>>>John, KN5L >>>>______________________________________________________________ >>>>Elecraft mailing list >>>>Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>>Help: http://mailman.qth.net/mmfaq.htm >>>>Post: mailto:[email protected] >>>> >>>>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:[email protected] >>> >>>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:[email protected] >> >>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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
