I agree an inhibit pin is a very good idea. One must always remember to connect it of course. The system needs to fail safe. QSK is not used above HF as much and a radio that automatically allows a delay is far safer than one that produces power immediately unless an inhibit line is used. If that inhibit line was an enable line, I think it would be far safer still.
For those who naively carp one should simply speed up ones amplifier - be aware that there are several things that must happen in the correct sequence. The RF relays must switch and settle, then the PA bias must switch, e.g. 350V to the screens for a tetrode. All this before the RF arrives. At HF this is easy, just use a pin diode or a vacuum relay for RF and a triode. At VHF is is much harder. PIN diodes are too detrimental to the noise figure for RF and the 350V screen supply tends to need a relay because of the shunt regulation. Good chunky high power coaxial RF relays available for sensible prices tend to be slow, even with a speed up circuit. They may switch in a few mS but the contacts may bounce for considerably longer. The TX might not mind but the isolation will be poor and the pre-amplifier will suffer. When you are switching a kW VHF amplifier all this really matters and asking for it to be done in less than 10mS is a challenge. Most of it is the RF relays and although small SMA relays do switch RF very quickly, they are only good for a few 100W. There are many K3 features that are totally useless for me. I don't suggest removing top band or AM to save money because I don't need it, so please don't suggest useful firmware features are unnecessary just because you don't need them. -- View this message in context: http://www.nabble.com/K3-and-linear-amp-tp16180386p16219261.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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
