[Elecraft] [K3S] intermittent RF path interruption

[Nr4c]

Well first I’d try with a “dummy” load. 

The swap antenna to Ant 1. 

Sent from my iPhone
...nr4c. bill


> On Apr 12, 2020, at 3:23 PM, Ben Gelb <ben.gelb at gmail.com> wrote:
> 
> A bit of a mystery w/ my K3S and I could use help figuring out what the
> problem might be.
> 
> Background: I have had the radio parked on 6m for several weeks (HF antenna
> temporarily out of commission) and have left it running (receive) for
> extended periods.
> 
> Recently, I have noticed that when I do sit down and try to operate, the
> radio will get into a mode where during TX the rig will indicate 0W forward
> power during transmit. Following this zero power TX, the RX will also go
> quiet. Then seems to stay that way for some time (not clear to me what
> makes it clear up... or if it ever does if left alone).
> 
> Some experiments I have done to try to figure out what is wrong:
> - Hitting the tune button also shows 0 power (instead of usual 10-15W) when
> radio gets stuck in this state.
> - Dialing the power down to where I hear the 100W PA switch out of line
> (relay click... around 8.0W) seems to immediate restore receive and also
> causes the rig to make power again on transmit. But when I turn it back
> past 8.0W, it appears to go back right back into the bad state (so suggests
> whatever the issue is, is in the 100W PA module).
> - Switching to another band and transmitting momentarily (think I tried
> 15m) will sometimes knock the radio out of this "bad" mode. But going back
> to 6 meters will eventually cause it to happen again. Usually pretty
> quickly (several seconds of TX).
> 
> Some other notes:
> - Antenna always measures 1.1:1 on the K3S display (when TX working
> correctly). Also checked w/ RigExpert. I don't think the antenna is the
> issue.
> - All my observations have only really been on ANT2 port (nothing connected
> to ANT1 presently).
> - Haven't really exhaustively tried to test band dependence of the behavior
> because I don't have an antenna on the other bands at the moment and not
> wild about trying to transmit into a big mismatch. So although it appears
> 6m related based on my observations, that might not be exactly
> representative of whats going on.
> 
> Posting here in case I've given enough clues for someone to suggest what
> may be wrong or how to narrow down further.
> 
> Thanks,
> Ben N1VF
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to nr4c at widomaker.com