[Boatanchors] Lysco 600S T/R Switch

[Bill Stewart]

I have a Lysco 600S that's about ready to put on the air. I noticed that it has a Lynmar Engineers Inc Trans-Receive Switch type TRS-1 which either came with it or was added later. The T/R switch uses a 6AH6 sharp cutoff RF pentode tube. There is a feed-thru with a mica cap which goes to the final var. cap. There is a phono jack on the top which I measured anywhere from around 5-8 Volts AC...this may vary with the RF output. I connected a 6.3 VAC relay to the phono jack but it didn't pull in but the switch output voltage did drop with the relay coil load (it still had close to 6VAC)

My first question is does anyone know anything about this T/R switch? The switch is built in a small mini-type box. Three wires connect below the xmtr chassis for B+, fil. and gnd. The phono jack is connected to a coil wound similar to a IF coil.
I guess that it senses RF thru the mica cap and this cuts the tube on and off for break-in keying.

My other question is has anyone rigged up a T/R switch for this xmtr? I don't like break-in keying on my boatanchors. Even if I can get this T/R switch to work I'm not sure I would want to use it. The xmtr B+ stays on all the time. The keying selector switch (S4) doesn't have a spare pole I can use for switching. I am considering moving the line from the modulator 6V6 cathode from S4D to the spare S4C connection and grounding it thru the key if I want to use the modulator (probably a rare occurrence considering the low power). Then S4D will be freed up to gnd a 6.3vac relay. I would like to keep any modifications to a minimum. Anyone have any thoughts on this? Are there any Lysco users out there?? Many thanks for any comments......73 de Bill K4JYS