[Hallicrafters] Headphones

[James Thayer]

Hi Mike,
     They appear to me to be high impedance 2000 ohm magnetic phones.  
I have a couple of pair somewhere around here. They probably date  
back to the 50's or earlier. Not sure about your brand but that type  
was used in the 20s on the old battery home radios of that era also.
Regards,
Jim Thayer W5JT

On Jul 5, 2005, at 6:20 PM, Langston, Mike wrote:

> Well, I started with some low impedance (8 ohm) Yaesu phones (Model
> YH-55). Unbelievable HUMMMMM when plugged into my SX-101A and worse on
> my SX-96. Neither of these rigs have HUMMMMM when using the speaker  
> (3.2
> ohm). Then I tried the Califone 2924 AV (600 ohm) recommended by  
> someone
> on the Hallicrafters reflector. Much better, but still so much HUMMMM
> that I would rather use the speaker. Then I found this old set of  
> phones
> that got thrown in with some other purchase I had made that I had  
> never
> put a plug on. Guess what? No HUMMMMMMM and they sound great. Now I'm
> curious what these are. Here's the identifying info:
>
>
>
> Alnico Magnetic
>
> No. 25
>
> C. F. Cannon Co.
>
> Springwater, N.Y.
>
>
>
> The headpiece is a metal frame with padded springsteel, the earpieces
> appear to be bakelite and they have black rubber covers (not the kind
> that cover the entire ear, just cushioning for the ear resulting in
> plenty of background noise getting through), the cord is flat 2
> conductor, brown in color and where the cords from each earpiece meet
> (about 18 inches) there is a brown plastic looking junction (riveted
> halves) with only one cord leaving the junction and on to the plug.  
> The
> earpiece cover unscrews and there is a thin metal disc (starting to  
> rust
> a bit) that can be removed revealing two oblong magnets with wire  
> wound
> around them. Here's my questions, can anyone tell how old these things
> are and maybe what impedance? Can anyone explain why these work so  
> well
> with the old receivers compared to the modern 600 ohm Califone?
>
>
>
> Thanks,
>
> Mike KL7CD
>
> Dallas-Ft. Worth
>
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