[NJARC] What is this?

[Goulart, Stephen F (Steve), ALABS]

Steve,
There are a lot of audio transformers and other gear which is 500/600 ohm. Most surplus receivers used a 500 ohm line output rather than an 8 ohm speaker output for example. I would imagine that your filter would be to use on the audio out rather than a mike input. Check the physical size for a clue. 

The 500/600 ohm line standard was started by the telephone company for transmission lines at a very early date and since the Bell System was responsible for most of the networking in the early days of broadcasting it moved into radio as well.
Steve Goulart

-----Original Message-----
From: njarc-bounces at mailman.qth.net
[mailto:njarc-bounces at mailman.qth.net]On Behalf Of StephenTetorka at cs.com
Sent: Friday, January 28, 2005 10:24 AM
To: njarc at mailman.qth.net
Subject: [NJARC] What is this?


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_______________________________________________
Hi Guys:

Item:
Chicago Transformer
"Low Pass Filter"
"Spec 8668"
"500 ohm line cutoff 3000 cycles"

Audio use with 500 ohm impedance mike cutting off frequencies above 3000 hertz?

Thanks,
Steve
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