[Boatanchors] Vintage Headset Impedance

Fri, 30 Apr 2004 14:23:46 EDT

Pete,

If you've seen a C-410 in the cord of a P-18, it never belonged there. Not 
that it wouldn't work, of course, if you turned it around backwards, but it was 
used with the HS-30 to turn it into a Hi-Z headset. Impedances are 8000:256 
ohms. I've seen it in one other cord but can't recall right now what it was. Not 
a common one. The other two versions of the HS-30 (out of a total of four) 
had a junction block about the same size as the C-410 but flat instead of almost 
cylindrical. And then there was also the HS-29 (I've never actually had one) 
that was made from two HS-30's with the left and right earplugs going to 
different audio sources.

BTW, I think I mistakenly said or at least implied that the HS-30 with the 
junction block instead of the C-410 transformer block was 500 or 600 ohms. It is 
actually 256 ohms (one model may have been called 270). 

In a message dated 4/30/2004 12:58:32 PM Central Daylight Time, 
[email protected] writes: 
> Can anyone tell me what the purpose of the bakelite unit coded C-410 often
> seen connected in-line on the P-18 headphones. Is it a transformer and what
> are its impedances?
> 

Robert & Susan Downs - Houston
<http://www.wa5cab.com> (Web Store)
<[email protected]> (Primary email)
<[email protected]> (Backup email)

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