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 The TR relay has been replaced by a TR switch that Dick, K5AND designed that uses Schrack relays that are spec'd to switch in 8 msec.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
