Read frequency of tuning fork on counter

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Dave Edwards:
Trying to read the frequency of a tuning fork using my counter.
I suspect my dynamic tape recorder microphone just does not have the
output required for the counter to trigger.

So, would you suggest a ceramic or crystal element....or is there a WAY better
method of doing this.....without building a circuit to add to the mix.

Thanks for any suggestions.

....Dave

Thomas Carpenter:
A thought,  record the tuning fork on your pc playback through speakers tap speakers for sampling. Heck even you cell phone might record well enough. I'm really thinking that an electret (Wide 30-15,000Hz frequency response) vs condenser (Wide 50-10,000Hz frequency response) crystal or ceramic would be better. wav or mpeg files

Tom Kb3hg

Dieter Kuespert:
You can measure very accurate using http://www.qsl.net/dl4yhf/spectra1.html
A laptop microphone is sufficeint. I used it for tuning low frequency generators.

Scott Schrader:
or wind a coil around the tuning fork, hook it to the freq counter, strike the fork and hold it to a magnet.  if there is enough wire, you can get enough voltage to feed the counter's chips.

the reverse was used in the 30s for master clock timing in radio.  General Radio had an oven-mounted tuning fork driven with big-boned triodes that output 115 volts at exactly 60 cycles to power clocks.  the triodes ran magnets that vibrated the fork.

this was before Hammond (the organ guy) slyly made the electric grid stable by giving away his then-signature product, the syncronous-motor clock, to power company executives.  they didn't keep good time until the plant operators started hanging on their controls and keeping the speed constant, and the power execs made it happen so they could keep the pretty clocks on their polished desks.

Clark McDonald:
What counter is involved?  Does it have preselector on it in order to get down into the audio region? 

What is the input spec for the counter?  Input Impedance may be 50 ohms and able to load down ANY mic output.


73

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