I didn't mean to hijack the thread "How to check the accuracy of an HP 5342A frequency counter". So I am starting a new thread. I will paste in what I placed in the other thread too.
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I've used beat frequency method WWV with my HP counter and RF generator to set the internal references in each. Once I have used the signal strength meter on my Radio Shack HF receiver DX-160 tuned to WWV to move imperceptibly in no-fade conditions, I will use a guitar tuner also and offset my RF generator from WWV? highest broadcast frequency (20MHZ if possible) and offset by +- 440HZ (20,000,440 HZ . That is the "A" note setting on the guitar tuner, you can use a lower octave for more accuracy, (220 hz offset), but your receiver may filter that audio freq out and you won't know why you can't hear the 'beat whistle', and/or your guitar tuner may filter more than mine does, and not allow you to see the first octave (x2).? Then have the tuner mic near the SW radio speaker, Adjust the RF level out on the RF generator so it mixes with WWV and not overpower it, and you center steady up the guitar tuner needle by adjusting the source, or whatever needs adjusting. Stay away from 5MHZ WWV, noisy and better accuracy during daytime up higher freqs. At least 15 MHZ. I've done it at 25 MHZ also when it was broadcast too.
Greg Muir chimed in;
Even calibration via WWV can be a real chore if you are located some distance from the transmitters and can only receive the sky wave instead of the ground wave signal.??The erratic movement of the received signal phase gets to a point where it becomes nearly impossible to determine where you are with the DUT setting unless you can do some time variant analysis.
It's nice to have GPS handy.
Greg
My response;
To address what Greg Muir stated, that's why I use the guitar tuner. I can 'hear' when the WWV signal fades away because the beat frequency of 440 hz goes away and the tuner needle will leave center, assuming you had the reference set correctly.
Actually, I would like someone who has a better reference source and a guitar tuner, HF receiver with strength meter, RF generator, and see how accurate my method is by comparison.
NielsenTelecom
Ok, Any takers? The best response from the guitar tuner is during the quiet time when the 'tic-toc' is the only WWV audio. It will just cause the tuner needle to jump. Also, I have been able to get the beat whistle using this method even when WWV was imperceptible to the ear. The guitar tuner does a great job of filtering only what it wants.
NielsenTelecom
