Wow! The old Trimm Radio headphones. I have one of those that my father
had. I don't know where or when he got them but they were around the
house as far back as I can remember. They became part of my homebrew
code oscillators and science projects when I was in grade school. They
were my first Novice headphones...boy did they make my ears hurt! I
think they cut off the circulation. Lately, though I find myself using
them again for cw. The metal diaphragms have a resonance that give them
built-in cw selectivity.
Fair Radio Sales still advertises Hi-Z 'phones.
For low-z phones with the Scout, I use a Radio Shack 500 to 8 ohm
transformer in a 35 mm film container. I hooked the low z side to the
Scout and the Hi z side to the headphones. Hi-z phones are happy with
this and the mismatch for low z phones provides some attenuation. An
easier way to do it is to use a small trim pot or even fixed resistors
to form a voltage divider.
Bob WB2VUF
Stuart Rohre wrote:
>
> Alan,
> The best solution I found was those surplus high impedance military phones,
> or even the 2000 ohm Commercial 1957 magnetic double headphones from Trimm
> Co. that we all had back then, (and I kept). With the addition of two foam
> pads form Walgreens you are all set with comfort and do not need to turn up
> the audio to where the display whine is heard.
> GL and 73,
> Stuart K5KVH
>
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