[Boatanchors] monaural headphones

[Richard Knoppow]

----- Original Message ----- 
From: "John King via Boatanchors" 
<boatanchors at mailman.qth.net>
To: <boatanchors at mailman.qth.net>
Sent: Monday, July 21, 2014 7:46 AM
Subject: [Boatanchors] monaural headphones


>I am looking for a source for monaural headphones. They do 
>not need to be high fidelity. Before anyone tells me, I 
>know that a  monaural to stereo adapter  can  be used or 
>that the two channels can be jumpered and other jury rigged 
>methods can be utilized but that is not what I am asking. I 
>am merely looking for a source of monaural cans that were 
>intended  to be used for that purpose on my numerous 
>boatanchor receivers. Yes I have numerous matching speakers 
>but often I want to check a speaker for a minute and don't 
>want to move a speaker, turn the receiver around and fool 
>with screws just to check out a receiver for a couple of 
>minutes. If I sound like a grouchy old man, I guess I am, 
>but years and  radio shack sales type electronics folks 
>will make you that way. Thanks, 73 and SMILE 
>!!!!!!!!!!!!!!!


     Try  http://www.oldradioparts.com/
It was reported that he was going out of business but the 
web site is still there. His list of headphones is at
http://www.oldradioparts.com/2a14fl.txt

     Make sure you read his instructions for ordering 
carefully.
He has mostly old type magnetic phones but sometimes other 
types show up.  The military type ANBH-1 and ANBH-1A are 
moving coil phones of good quality based on a Permoflux 
commercial design. For CW the magnetic type are fine, most 
are fairly sharply resonant around 1 khz. I am currently 
using Trimm Commerical phones made for Radiomarine for CW. 
The granddaddy of most magnetic phones is the Western 
Electric 509W. Baldwin phones are balanced armature type 
with mica diaphragms and were preferred by a lot of old time 
wireless operators.  Magnetic types have impedances that 
vary from perhaps 25,000 ohms down to 50 ohms per pair 
depending on what they were designed for. Generally, 
impedance is about five to seven times the DC resistance.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com