Gregg, Unless you have changed the open frame relay in the SB-220, it will take at least 15 ms to switch and be clear of the contact bounce. I would suggest you change the stock relay for something faster.
73, Don W3FPR On 4/29/2012 8:55 AM, Gregg Marco W6IZT wrote: > I use my K3 on 6 meters with a concerted SB-220. When using the PR6 > connected to the KXV3 as intended and using the amp, the GaAs FET is > destroyed immediately. My work around was to employ an external TR relay on > the K3 to switch TX RX, connecting the PR6 to the RX side of the relay and > to the RX input of the KXV3.Using this arrangement has worked fine for the > past few years. > > With E skip season approaching I thought that I would try to resolve this > problem and get rid of the extra RF plumbing. > > My initial thought was the TR relay in the amp might be too slow and RF was > being reflected back into the K3 during the transition from TX to RX. After > looking at the K3 block diagram I doubt that this is the case as the PR-6 > should be switched out of the circuit well before any RF is present at the > output. > > For reference the TR relays in the amp are spec'ed at 8 msec to switch and > the K3 is set at 8 msec TX delay, which I believe is the default. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
