I'm not guru enough to call myself an authority but my first reaction to the symptoms is that the PA crash damaged one or both diodes at the output of the K3 that detect forward and reverse power. The rig intermittently throttles itself back when it 'thinks' the output is too high or swr too high.
Don K7FJ > Can anyone help the team on Fiji? > > Rys - I will follow up with a response from the reflector if I see it. > > 73 -- Brian -- K1LI > > ---------- Forwarded message ---------- > From: Ryszard Tymkiewicz <r...@ippt.gov.pl> > Date: Mon, Oct 12, 2009 at 2:04 AM > Subject: Topband: Fw: 3d2kj > To: topb...@contesting.com > > > I'm sorry I attache longer text here but our friends on Fiji have serious > problems. > Below text were sent to Elecraft too but because of holidays I'm not sure > if > they will be able to read it now. > Maybe someone will be able to help them? > > 73 Rys > SP5EWY > > ========================================================= > > Dear Sir, > My callsign is 3D2KJ (SP5DRH at home), We are on a dx-pedition on Fiji > with the main > interest to activate 160m. We have here two rigs: K2 and K3 in use. The > last night we have encountered a serious trouble with our K3 (S/N 1739) > Since that time, we are observing short (a few seconds) lost of power on > 160m, while CW is used. This behavior concerns ONLY 160m! That happens > with a small power level being set at 6W, as we are using this rig to > drive an external PA. Then, the output returns to the previous level, > with a short view of a full bar on the LCD display. We tried to find if > it occurs on TUNE position as well, but it looks that it happens very > rarely there. The rate of this behavior seems to be unpredictable but it > is sometimes a few times within a minute! On other bands everything is > OK. It looks, moreover, that the > rig produces sometimes some spurious signals on 160m resulting an odd > behavior of our home made PA, while using a K2 instead of K3 solves the > problem. > This makes us unhappy since this failure might jeopardize our program. > Since one of us > (3d2mj – home sp5eaq) is an engineer in electronics, we have > performed several tests and we are now convinced that the nature of the > problem is of K3. We re-initialized the rig and nothing changed. > The transceiver is loaded with the low SWR input of the PA but the same > problem happens if it is loaded just with an antenna. Any local external > support is impossible, we have basic tools (including soldering iron), > some spare parts (but not K3 origin) and an AC/DC meter. There is a > possibility that the problem began during a crash of PA during > transmition without load (failure of antenna). The > PA has been then repaired, but soon we found the K3 problem. It might be > just a coincidence since before we had used 15W of drive. > 73 de 3d2kj&3d2mj > ========================================================== > _______________________________________________ > Topband mailing list > topb...@contesting.com > http://lists.contesting.com/mailman/listinfo/topband > ______________________________________________________________ > 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
