Hello John, My K3 is driving my 30L1 without any problems. However I did need to construct an interface to key the amp. The key line is a -170 vdc and requires 100 ma. to actuate the relay. You can check this by measuring the - volts before keying. And then put a ma meter in series to ground and measure the keyed current. No drive required for these measurements.
I used a NPN high voltage transistor, (NTE 397), for the interface. And a couple of resistors all in a small plastic box. The collector is attached directly to the keying line of the 30L1. I attached the emitter of the transistor the 12 dc supply on the rear apron of the K3. I attached the base of the transistor through a 2.7k resistor to the key output on the rear apron of the K3. Between the base and emitter I placed a 4.7k resistor. Noting trick about the arrangement but you want to be sure that the transistor is saturated for cool operation. Smith Bradford W9HAK ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
