"- exray -" wrote in message
...
Rob Mills wrote:



stuff requires crimp connectors. Trying to convert from one type of
connector to another is a nightmare!


That's putting it mildly, never could get all those wires in that tip
much less get them to stay. RM~

The trick is to "whip" or wrap the ends of the tinsel wire with a small
gauge solid wire. Thats not particularly easy either but it works and is
neat. Working a couple inches back from the end helps a lot - then cut
off the excess.

-Bill

What about impedance matching?
Not familar with S-38 but my S-53 originally had a similar arrangement;
namely pin jacks and a small slide switch to switch from speaker to
head-phones.
That's now converted to a plug in quarter inch jack at rear of my S-53;
speaker disconnects when head-phones plugged in. But both speaker and phones
use the same output winding of the audio output transformer in the plate of
the S-53s 6K6 output tube.**
So if the S-38 is similar it suggests that the audio output is 'low
impedance'.
If someone used high impedance phones one might expect poor audio quality?
Not that high fidelity is normally a requirement when using headphones on a
shortwave 'communications type" receiver!
Or were those 'vintage' type phones that have been mentioned, in foregoing,
low/medium impedance anyway?
One reason I ask is that I have old German headphones in which, I think this
is correct, each earpiece is 2000 ohms; total 4000, probably originally for
a crystal set? I do know that you can hold one lead in hand and touch
almost anything metal with the other lead and get electrical noise!
Sensitive eh?

Impedances: Plate = say 5000 ohms. Speaker = 4 ohms. Phones = 600 ohms.
Therefo
5000/ 4 = 1250 transformer turns ratio = sq root of 1250 = 35
5000/600 = 8.4 transformer turns ratio = sq root of 8.4 = 2.9