K2 Alignment Part II
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Hi Everyone!
I am starting the second part of the K2 alignment. I went and redid the first part of the alignment because I tweaked R1 by accident. Some of the numbers came out different than the last time because I had more stuff on the board. I do have a question about the 4 MHz Oscillator Calibration: This may sound like a stupid question, but what am I supposed to be listening for on my receiver when I zero-beat to the crystal? I am hearing a tone, and it changes when I adjust C22, but I am not sure to what tone I need to adjust it to. Any clarification on this would be great! Thanks & 73, David KC9EHQ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Typically "zero beat" means getting the "beat note" down to zero, where you
hear no tone. In the days of AM transmission, you'd hear the beat note between the "other" station and could get your transmitter onto the same frequency by keying your transmitter (at low power) with a "spot" function, and then adjust your transmitter VFO for the lowest possible beat note. If you were lucky and had a good audio system and a fine-grained stable VFO, as the note got really low you'd hear a rhythmic pulsing that you can adjust to very close to zero. In other more modern use with CW, you hear two tones and you need to line them up. If you're asked to "zero beat" with another station on CW, you want your transceiver side tone to match the other station's tone, and you want the transceiver side tone to be offset appropriately to make this happen. Many transceivers have a "PITCH" control to set the CW offset tone for user preference. Some advanced transceivers have a CW "Spot" function that adjusts the transceiver VFO to match the side tone, putting you on the right frequency as another CW signal. In SSB communications it's a little harder, you have to tune your VFO so that the "other guy" speech sounds natural. If you dont know the other guys' voice, you might tend to be off a few cycles. I can understand SSB signals at some distance from zero beat, and in the heat of a contest I might not tune very accurately. Fortunately many others can understand this as well. Some of us have more trouble than others matching two pitches. People who do this well scored high on the Navy Boot Camp Sonar aptitude test. Others of us are "tone deaf" and cannot discern the difference between two notes that don't differ by much. Dick -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of David Dietrich Sent: Saturday, August 27, 2011 12:30 PM To: [hidden email] Subject: [Elecraft] K2 Alignment Part II Hi Everyone! I am starting the second part of the K2 alignment. I went and redid the first part of the alignment because I tweaked R1 by accident. Some of the numbers came out different than the last time because I had more stuff on the board. I do have a question about the 4 MHz Oscillator Calibration: This may sound like a stupid question, but what am I supposed to be listening for on my receiver when I zero-beat to the crystal? I am hearing a tone, and it changes when I adjust C22, but I am not sure to what tone I need to adjust it to. Any clarification on this would be great! Thanks & 73, David KC9EHQ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by David Dietrich
David,
Bypass that - that initial "4 MHz Oscillator Test" is just to make certain the 4 MHz oscillator is working. What you are doing is comparing the 4 MHz oscillator output to what the firmware "thinks" is a 4 MHz source. So as long as it is oscillating, the test will always pass. If calibration of the 4 MHz oscillator is your goal, and you have the K2 capable of receiving WWV (or some other station of known frequency), go to my website www.w3fpr.com and look at the K2 Dial Calibration article. The N6KR method will provide you with precise setting of C22 with no external equipment, and that method compensates for any variables in the various oscillators involved. The use of Spectrogram or other audio spectrum analyzer software to detect the tones transmitted by WWV is strongly recommended. Tuning to the "standard" station correctly is the key to success when using that procedure. 73, Don W3FPR On 8/27/2011 3:30 PM, David Dietrich wrote: > Hi Everyone! > > I am starting the second part of the K2 alignment. I went and redid the first part of the alignment because I tweaked R1 by accident. Some of the numbers came out different than the last time because I had more stuff on the board. > > I do have a question about the 4 MHz Oscillator Calibration: > > This may sound like a stupid question, but what am I supposed to be listening for on my receiver when I zero-beat to the crystal? I am hearing a tone, and it changes when I adjust C22, but I am not sure to what tone I need to adjust it to. > > Any clarification on this would be great! > > Thanks& 73, > > David > KC9EHQ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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