> The TR relay has been replaced by a TR switch that Dick, K5AND > designed that uses Schrack relays that are spec'd to switch in 8 > msec.
Is the K5AND TR Switch design documented anywhere? Does it use a single relay or multiple relays? Is there any chance that the input replay is dropping out while the SB-200 is still making RF? Do you have any separate receive antennas connected to the "bypass" ports on the PR6? Do the receive antennas have a "front end saver" inline? Short of a problem elsewhere, I do not see how 6 meter RF from the amplifier can get back through the K3 T/R switch, HPA and LPA to even get to the PR6. 73, ... Joe, W4TV On 4/29/2012 11:56 AM, Gregg Marco W6IZT wrote: > Joe: > > It is a 6m only amp. Yes, the K3 is set to bypass the PR6 when on HF. The TR > relay has been replaced by a TR switch that Dick, K5AND designed that uses > Schrack relays that are spec'd to switch in 8 msec. > > 73 > Gregg > > -----Original Message----- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Joe Subich, W4TV > Sent: Sunday, April 29, 2012 11:34 AM > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] PR-6 issue when QRO > > > Greg, > > Is that SB-200 a "modified for 6 meters only" amplifier, one that has six > meters added to the HF bands or is the problem happening when operating on > HF bands? > > Is the K3/PR6 configured to bypass and turn the PR6 off when operating on > HF? > > 73, > > ... Joe, W4TV > > > On 4/29/2012 11:10 AM, Gregg Marco W6IZT wrote: >> 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 >> > ______________________________________________________________ > 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 > > ______________________________________________________________ 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