On Tue, 2009-01-27 at 01:58, Julian, G4ILO wrote: > Bill W4ZV wrote: ... > > ...I would never intentionally run mine at the lower end of that range. > > If you have any concerns about overshoot when turning on your power > > supply, always turn the PS on a few seconds before the K3. > > > > But the K3 power switch is a "soft" switch isn't it, so some electronics are > still connected to the supply even when the switch is off? ...
The K3 has a transient suppressor that should blow the fuse if a big enough transient appears on the power connector. Looking at the RF board schematic I see a BZW50-15 overvoltage protection diode connected between ground and +12V on the radio side of the fuse. I downloaded the data sheet for that part - it looks like the breakdown voltage is 16.6V minimum at 1 mA. The actual clamp voltage is a complicated function of peak current and pulse width, but presumably Elecraft chose a part that adequately protects the radio. Al N1AL _______________________________________________ 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
