Work is progressing on the 15, I have some new felt washers for the main shaft, new bearings for the motor, and some different palettes to change from the weather type face to the communications type face. I have my work cut out for me tonight and tomorrow.

I am thinking through how I am connecting this unit to the TU-170, and have a question. I have receive figured out and working, the audio from the radio/pc goes into the TU-170, and I have the LOOP output connected to the magnets on the printer unit. This works as it should. (I have the printer magnet and keyboard circuits separated with two 1/4" plugs)

My question comes in hooking up the keyboard of the Model 15 to the radio. I understand I am basically providing a quickly opening and closing set of contacts to create the RTTY 'signal' to transmit. 

Should I be connecting the keyboard up to the terminal unit, or directly to the transceiver?

I have Yaesu rigs, an FT-991a and an FT-DX10. Both have the same interface plug, so I think they would be wired the same way (I did verify this with both manuals and plug diagrams). Should I be connecting to that connector from the teletype keyboard?

Or...

Do I connect the outputs of the terminal unit to the transceiver? I see the 'Transmitter' plug on the unit, and understand that is what I would use for output, but how do I connect the keyboard to the TU? The manual says the keyboard should be wired in series with the magnets, does the terminal unit sense the rise and drop of the loop as input from the keyboard? (I guess I am still a little unsure of how the loop system is supposed to work).

If I wire the teletype as a series connection, then I can't use my rs-232/AFSK/ASCII interface I built, as it requires the printer and keyboard to be separate connections (Not series) Would it be OK to make an interface that would switch these two connectors (Mag and Kbd) from series to separate and back to series when needed?

Any pointers would be helpful, I appreciate you taking the time to read this novel...

;)

Thanks!

Steve

KB0WSV