Wireless microphone crystals

Jan 03, 2014 2 Replies
S

Hi,



I ended up with a VERY old stack of 50-100 paper envelopes, each containing at least one crystal HC-49 full size. Some are new, some pulls.



There are alien markings like 77-TX and T82B-TX as well as frequency numbers such as 154.60, 171.025, etc. The frequency numbers are related to the stamped crystal frequencies by a factor such as: fcrystal = (1/2) * (frequency - 21.4MHz)



Are these things of any use to anyone here? If so, they're yours for the cost of postage (should be less than $15 to anywhere in US or Canada). Otherwise, they'll go out in the trash



I imagine modern mics are all synthesized from a single crystal source.



Best regards,



--sp


Best regards, Spehro Pefhany


"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com
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P

"Spehro Pefhany"

** Put them on Ebay.

Bet someone bids a couple of bucks each for them.

BTW:

Transmit crystals (TX) used in most radio mics are a special cut that allows them to be easily "pulled" by up to 0.05% to create FM.

... Phil

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I might guess that 77-TX and 82B-TX refer to marine VHF channels. In case you can determine the frequencies, Ch 77 is 156.875 and 82B is

161.725 MHz.
Peter Bennett, VE7CEI Vancouver BC peterbb (at) telus.net Vancouver Power Squadron: http://vancouver.powersquadron.ca
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