Ralph, Put the resistor between pins 1 and 6 in the *plug* for the Heil Proset, rather than in the radio. That way the Rascal interface works, and no blocking capacitor is necessary. Another advantage is that you can use other microphones that don't require a bias voltage with the K2. The Heil dynamic elements still sound significantly better than the electret elements in the MH-2 (discontinued) and Heil Proset boom microphone, although the K2 output is somewhat less. When I use the K2 with a Heil HC-5 element and a linear RF amplifier, I get the best audio reports. The Proset is still useful for Field Day and other operations away from home.
Although there are published pre-amp circuits for using low-output dynamic mikes with the K2, it isn't clear to me why it wasn't designed with higher audio gain to start with. That way higher quality microphones could be used. The K2 is capable of quite high quality transmit audio, but it isn't as apparent with the electret microphones. Icom et al have made the break with electrets starting with their Pro II and later rigs. We are still using the equivalent of the older style Icom mikes. Andy W9NJY Milwaukee K2 2651 KX1 1139 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
