[Syl]

Syl, I know the cart is bad as most are of this type. Not sure what to do about it. (West Tech rebuild for a customer didn't sound right last year) The brand of cart says "American" on it, not sure if it's original, but fits in perfect.

Nothing has changed.

As for the cartridge, it is most probably the original. I have done many "American" cartridge -gold body- in the past
for similar phonos.

I have recapped/ restuffed it already, and it sends out a clean carrier. I tried connecting a small mp3 player to the tone arm leads, and only a very weak sound is transmitted, at full volume of the player.

You need a solid 3V to drive the transmitter. Anything below that will work but offer a weak signal and lots of noise.

You could replace with an 84T, rebuild the original (not that difficult) or use a modern ceramic cartridge and a
tiny transistor preamp using the cathode bias voltage of the input tube to feed the said preamp.
I've built a few preamps using surface mount transistors and resistors encapsulated in epoxy. The result
looks much like a post stamp with 3 tiny wires. I glued it right behind the volume pot with only one additional wire
going to the small chassis for the +Vcc. One wire goes to ground (via the pot's shell, one goes to the input
and the third one goes to +Vcc/pot). Gives a gain of around 4. Enough to drive this transmitter using
a 0,7V ceramic cartridge.

[Image: http://www.oldradioz.com/howto/preamp.jpg]

[Image: http://www.oldradioz.com/howto/smt_preamp_1.jpg]

[Image: http://www.oldradioz.com/howto/smt_preamp_2.jpg]

I use double side sticky tape for mounting the preamp to the pot.
Not the 4 wires on the prototype. The final version has only 3 wires from wich only
one goes to the chassis.

Syl