Thanks Michael, Andy, and all for the original thread. It made me focus on proper use of my KPA500 which has really done a great job for me since I acquired it and a KAT500 over the summer.
Retitled this message because I do not want to hijack/derail the original conversation. What I want to know... is there no repair for absent minded button pushing and thoughtless antenna positioning? So that I don't forget again... A hopefully instructional "mea culpa" follows: I have been using the IC-7000 for 2M APRS ops with a Diamond VX2000 vertical. Also have been experimenting with HF simplex D-Star and Free DV digital voice recently. The KPA500 has been instrumental for DV ops because of recent squirrely propagation... Mistake 1: Over the summer, I forgot to shut down the packet ops and ground 6/2/440 tri-band antenna while using a "nearby" halo with 350 watts 6M DV. That blew the 2M front end of the IC-7000. Matt at SARTS/ICOM in Michigan repaired it and I put together a protection relay circuit to ground the vertical if I forgot again. That should have solved the issue... Mistake 2: A relay contact was faulty (and I did not test it properly) and a month later, an adventure on 6M DV mode took the 7000 front end again! Matt was kind about fixing it ...again... Here I claim total stupidity along with absent mindedness - I rebuilt the protection circuit, tested it, it "seemed" to work fine... but it failed again a month later! Mistake 3: Failed, because I had removed the dummy load and *forgotten* to replace it along with a key ground strap, which again left the receiver 2M front end exposed. Kindly, Matt agreed to fix the 7000 a 3rd time... The 7000 will not go back into service until I have completely re-arranged the station set up because, to top off this comedy of errors... I totally ignored one basic issue: Original Mistake: the vertical and halo antennas were mounted on the same mast because "I never planned" to use them at the same time. This is where stupidity/laziness compounded with my absent minded operating practices to create the "perfect storm". Until I started using the KPA500, the halo antenna field strength was not such that the 7000's 2M receiver section was stressed by the signal strength from vertical, so I got complacent. Add in the KPA500 and smoke is let out of Q551 in the IC-7000. I am *sure* that no one on this group does this sort of sloppy engineering, but let it serve as a not-so-subtle reminder that a station layout should not be organically grown, but should be planned carefully with this sort of damaging interaction in mind. Enjoy the laugh at my expense. KD4IZ Jack Spitznagel FM19oo -----Original Message----- From: Michael Walker <va...@portcredit.net> Sent: Monday, November 19, 2018 19:52 To: ANDY DURBIN <a.dur...@msn.com> Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] Killed the KPA500 :) Knowing what I did while transmitting at 100 watts of msk144, I’m surprised the damage isn’t worse. The protection circuits did the best they could of. If you own any amp, you always need to be aware of the risk. I would never rely on the automation to 100% protected any amp. If you are worried about your amplifier and anyway I highly recommend you have checklist handy every time you turn it on and change Bands. Never depend on the protection circuits. I know I’m preaching to the choir too many people, however it is imperative you understand exactly how your amp works, how it’s wired, and how it interfaces with any HF radio. Mike va3mw Sent from my iPad > On Nov 19, 2018, at 6:45 PM, ANDY DURBIN <a.dur...@msn.com> wrote: > > "The support team at Elecraft got back to me and the required parts to repair > the board are on the way. Nice job guys." > > > But the question remains - Why didn't the designed-in protections work? This > new KPA500 owner would appreciate an answer from Elecraft. > > > Andy, k3wyc > > > ______________________________________________________________ > 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 Message delivered to > va...@portcredit.net ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
