[davemc]

Correction on the AES PT-2K alternative.

Looks like they are NO LONGER SOLD. There were a close-out item awhile back. I have also seen these sold on eBay. Apparently they were used in a vacuum tube transmitter to drive a class B modulator stage. I have a handful of them. Let me know if you need one - but be advised - your radio will not sound as good as it should (BUT IT WILL AT LEAST WORK!) Here's the complete specification:

PRIMARY: Z = 10K Ohms*, 10 ma. DC; Res. = 266 Ohms; Leads: Blue to driver plate; Red to B+ line
SECONDARY: Z = 2.5K Ohms* with CT; DC Res. = 170 Ohms, Leads: yellow to modulator tube 1 grid; black (CT) to bias supply, green to modulator tube 2 grid
IMPEDANCE RATIO: Full Pri. to Full Sec. = 4 : 1, step-down
TURNS RATIO: Pri. to ½ Sec. = 2.8 : 1, step-down (NOTE: should be 2:1 in your radio - so some loss of audio will result)
POWER RATING: 8 Watts, max.
FREQUENCY RESPONSE: 150 - 15,000 Hz., -3.8\+0.1 dB. (unloaded)
DC OPERATING VOLTAGE: 340 Volts (recommended)
HI-POT TEST: Winding-to-winding and windings-to-core @ 2 KV DC: Pass
CORE: silicon steel, E-I, interleaved laminations
MOUNTING CENTERS: 1.75 inches
*(Impedances verified with General Radio 1650B RLC Bridge