The Elecraft KPA500 silent QSK is achieved without expensive PIN diodes but rather with relatively inexpensive switching diodes. I’ll guess that the 1500 watt Elecraft prototype amp of some years ago used a similar inexpensive, silent design.
Avoiding QSK should be because of operator preference not because of fear of relay failure. In the case of operating non-QSK, it’s vital for the operator to keep calls short and not be caught in a cycle of doubling with the DX that’s heard all too often. My Alpha 87A of 17 years or so has never had a PIN diode failure. When the 87A was first introduced there were indeed PIN diode failures. This was attributed to a bad batch (or batches?) of PIN diodes. Subsequent runs of 87A's ceased to exhibit PIN diode failures. Yet the urban legend persists that 87A’s should be avoided because of the PIN diodes - which are expensive to replace. The real question is why amplifier manufacturers continue to use vacuum relays when inexpensive switching diodes can do the job. Thank you Elecraft. 73 - Steve WB6RSE ______________________________________________________________ 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 Message delivered to [email protected]
