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Anyone Need these Ceramic Resonators?

chemelec

Well-Known Member
Thread starter #1
These are Ceramic Resonators.

I have Hundreds of them in these Frequencies.
They are FREE, Except for the Shipping Cost.
(Shipping Cost Depends on the Weight of Parcel and Your Location. *I Mail out from Canada*)

I Can't say much for their: +/- 1KHz though
Measuring 3 of the 305 ones, I get a Frequency of 293 KHz on all 3 of them.
Similar Off-Frequency Readings on the Other ones also.
Other than That, They seem Stable.


Crystal Resonators-1.JPG
 
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unclejed613

Well-Known Member
#2
interesting... there are two effects that occur at different frequencies. Fa is the parallel resonant frequency which is the frequency that the crystal is a high impedance, and Fr which is the series resonant frequency, where the crystal is a low impedance. if you connect a signal generator across the crystal. and connect the oscope across it as well, there will be a frequency where the voltage peaks, this is Fa, and there will be a frequency where the voltage dips, that is Fr. Fr is lower than Fa
 

chemelec

Well-Known Member
Thread starter #3
I didn't Notice any PEAK on the scope, Just Shorted out the signal at resonance.
 

unclejed613

Well-Known Member
#4
I didn't Notice any PEAK on the scope, Just Shorted out the signal at resonance.
that's the series resonant point... sometimes it's hard to see the parallel resonant point. an RF sweep generator (or a signal generator with a wide FM modulator) might be useful in plotting it.

or build an oscillator and see what frequency they oscillate at http://www.circuitstoday.com/crystal-oscillator

there's two oscillators there, one for series, and one for parallel resonant modes.
 
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chemelec

Well-Known Member
Thread starter #5
Well I don't have any use for them, So I can't be bothered in Checking them further.
Seems no one else wants them either, so they will soon just go in the GARBAGE CAN.
 

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