[ARC5] Zero Beat Question

[Richard Knoppow]

     Exactly. Where you are zeroing to an outside signal, for instance 
adjusting a calibrator to WWV the BFO can be used to give a tone that 
you can hear waxing and waning in time with the beat. By using this 
method you can adjust two oscillators to a within a fraction of a cycle 
of each other. An AM signal is not as easy but can be used, for 
instance, the tone modulation on WWV will follow the beat. The problem 
is that you can be beating the modulator tone. If you get an approximate 
beat on the carrier you can discriminate between the carrier and the 
modulation. Since this is a signal generator there is no third 
oscillator but the modulation "might" work. I say might because it is FM 
modulated.  I think this is actually a military version of a Polarad 
generator. It might be possible to find a more complete manual for the 
Polarad if you knew the civilian model number.

On 7/7/2016 5:57 PM, hwhall at compuserve.com wrote:
>>
> If you do you can probably use
> it to determine the exact zero beat by listening to it wax and wane.
>>
>
> I've noticed many radios, when you are very close to zero beat & the
> beatnote is too low to hear as a tone, the volume of the background hiss
> of the radio will be heard to rise & fall in step with the slow
> beatnote, so that you can get quite close to zero by tweaking until the
> rise & fall slows to a stop or nearly so. I think that's what he meant
> by "wax and wane."
>
> Wayne
> WB4OGM

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL