On receive we had persistent problems with people using lesser receivers and similar transmit power not being able to copy us because of QRM. DLs especially. We heard many very strong signals but none excessively wide.
We also had system problems though not the same, or at least the same but partly fixed. In our case the 9-way D connector was at fault, unless fully screwed in it was found to not be making a good contact. Fully screwing it in fixed that of course, nothing to do with the K3. Our main K3 related problem was the inconsistent power output. We were also using a pair of 4CX250Bs, parallel rather than push pull. To avoid over drive splatter, the amplifier trips out if any significant grid current occurs. The power spikes I have noted before made tuning up the drive with the PA on impossible. The correct drive was set, in incremental steps with the spike dealt with by keying with the PA off for the first transmission, then enabling the PA and seeing if the drive was sufficient. Once set the power would not stay fixed, it would sometimes drop by maybe 2-3 dB. Just adjusting the power one step up or down brought it back but with the usual initial spike that would on occasion trip the amplifier protection. After a couple of overs the power would drop back again. While setting up we also did some transmit cleanliness checks with local stations. The K3 + XV144 at about 7W output driving the pair of 4CX250Bs was reported to be exceptionally clean with very good audio. Considering this, the K3 plus XV144 while probably the best combination I have ever come across on receive is not ready for use on transmit just yet because of the ALC issue if you use a sensitive amplifier. One other minor point, with large chunky VHF coaxial relays, the 20mS TX delay is not quite long enough, but still much better than those rigs with no TX delay at all! You probably still need a sequencer. Mike Giulio Pico wrote: > > Before you ask... > Firmware Revisions: MCU 2.34; DSP 1.89. > > 73 de Giulio IW3HVB. > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > -- View this message in context: http://n2.nabble.com/K3-and-XV144-strange-behaviour-tp1079275p1079315.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
