Don: I have replaced the open frame relay with Schrack relays
73 Gregg -----Original Message----- From: Don Wilhelm [mailto:w3...@embarqmail.com] Sent: Sunday, April 29, 2012 10:12 AM To: Gregg Marco W6IZT Cc: 'elecraft' Subject: Re: [Elecraft] PR-6 issue when QRO 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
