[Elecraft] K2 and Kenwood TL-120 linear

[Bob Towers]

Trev,

Well, I got the linear working OK, at least on digital modes which are 99% of my QSOs.

I'm switching it on and off via the COM1 port and an opto-isolator. The opto-isolator switches the base to collector connection (12K resistor in series) of the switching transistor in the main relay circuit of the TL-120. I could have just grounded the bottom end of the main relay (~40mA current, well within the 4N25 opto-isolator limits), but I reckoned the final solution was the more elegant.

K2 minimum drive (~0.1W indicated) gives me 30W from the TL-120 at the ATU. It'll run 50 watts RTTY without the fan coming on.

Thanks again and 73

Bob
2M0KDZ

PS Now for SSB....