[Hallicrafters] Re Stereo To Mono For Headphones

[Duane Fischer, W8DBF]

Courtesy of KO6BB, who still does repair work part time for a local store in his
home state and has decades of audio experience: 
	
	
First, you really "don't" want to cut those cords on modern headsets to try
to rewire them as it is nearly impossible to do anything with those fine
wires and have them at all reliable.

Secondly, most of them have earpieces that are pretty close to 8 Ohms, some
as high as 30 Ohms each.  What this means is that even if you do rewire them
and put them in series about the highest impedance that you're going to see
is in the area of 16-60 Ohms, nowhere near a good match to the 600-2000 Ohm
output impedance of many of the old receivers.  (headphone jacks on some
receivers such as the cheapie S-120 actually are tied into the speaker lead
and are already low impedance).  This usually means a transformer or small
amplifier is needed for optimum sound anyway.  (I often use a active audio
filter between headset and radio to match things up).

To adapt a stereo headset to mono in itself is pretty easy as there are
adapters that can be bought that are a stereo jack to mono plug, just plug
the headset into one of these. Duane, I may even have one around here somewhere
yet.  Lacking that you can tape a 1/4 inch mono plug and put on one end of a
cable and a stereo jack wired in parallel on the other end.  Insert between
headset and radio.