It means the two of them agree with each other.
If one of them is off, the other one must be off by the exact same error.
Using a reference to calibrate another unit calls for a reference you can trust.
WWV is hard to beat when you can hear it.
Best way is to wait for the parts of the hour that have the tone modulation. It's a lot easier to hear "zero beat" by listening to the fade in and out of the tone when you're within a few Hz of zero beat. Harder to do on just a dead carrier.
73
If one of them is off, the other one must be off by the exact same error.
Using a reference to calibrate another unit calls for a reference you can trust.
WWV is hard to beat when you can hear it.
Best way is to wait for the parts of the hour that have the tone modulation. It's a lot easier to hear "zero beat" by listening to the fade in and out of the tone when you're within a few Hz of zero beat. Harder to do on just a dead carrier.
73
...runna pile-up on 6m SSB