[ARC5] The not-so humble BC-221/LM-xx frequency meters.

[Bill Cromwell]

Hi Richard,

The soundcard (spectral display) clearly identifies the sidebands 
(modulation) and the carrier so there is another vote for that method. I 
kind of thought by now somebody would have posted a link to 
'introductory' information about using gps. I can probably dig that out 
for myself.

73,

Bill  KU8H

On 12/24/2016 05:40 PM, Richard Knoppow wrote:
>    Hearing goes down pretty low as you can prove with a pair of high 
> quality headphones and a clean oscillator.
>    Finding a zero beat when the frequencies are very close requires a 
> third oscillator such as the BFO on a receiver. When the two test 
> signals are very close the BFO audio beat can be heard waxing and 
> waning. You can determine a beat by ear or on the S-meter when the 
> beat is a few seconds long.
>     A care when beating to WWV is to be careful you don't zero on the 
> modulation frequency. Sometimes it difficult to know when you are on 
> the carrier. Wait until the unmodulated period to be sure. A sharp 
> crystal filter will help because it can be set on the carrier which is 
> always stronger than the sidebands.
>
> On 12/24/2016 2:27 PM, Bill Cromwell wrote:
>> Hi Les,
>>
>> Peoples' hearing response varies all over the place. You don't see me
>> pooh-poohing the audiophools because I cannot prove they don't hear the
>> difference. I do have a lot of doubts. I play music and I have seen
>> numbers as low as the 20s in cps and as high as 100 or more. When we
>> hear '60 cycle' hum we are supposedly hearing a harmonic of 60. Maybe
>> some of us can hear dog whistles, too. I used to interpolate between the
>> two points where I lost the note on the low side and on the high side.
>> Then the bobbling, wobbling S-meter. Then I got a scope and thought I
>> was in hog heaven. Most recently I have been using the soundcard
>> software as I described. I am also planning to look into the gps
>> signals. I suspect that if I have a gps reference signal and a signal
>> "in the wild" I need some means to measure the relationship between the
>> wild signal and the reference signal (gps) if I am to tame the wild 
>> signal.
>
>

-- 
bark less - wag more