K3: Strange behavior on 80m
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All:
In SS this weekend, I noticed something "new" with my K3: When attempting to transmit a low power tune signal (I'm set for 10 watts out on tune) below, say 3.520, the power out and swr meters begin to oscillate wildly. Going above 3.520, everything looks and works normally. If I key the transmitter using the TUNE function (press and hold XMIT), then sweep the VFO below 3.520, the rig transmits fine at any power level but does not receive (see below) until I move the vfo, whereupon it starts the oscillation again. Listening on the receiver, when I tune below 3.517.70, the receiver stops hearing anything on the band and what sounds like distorted voice audio from a local Broadcaster is heard. I have a 50kw AM Broadcaster 5 miles away on 970kHz, BTW, its their audio that I'm hearing. Its completely unintelligible, but I can correlate that it's the same audio when they stop modulation or go to commercials. Immediately when passing 3.517.70 going up in the band, the receiver returns to normal amateur band reception, and the distorted audio goes completely away. I have made a recording in case Elecraft wants to hear what this sounds like. Tested this on SSB and CW, and find that the change to distorted voice audio happens at 3.517.70 on cw, 3.519.30 on LSB and 3.516.30 on USB. This switch point appears consistent, as I have repeated it several times. I don't have the NB or NR on, and turning these on don't change the result. This is with K3 # 3192 using the recalled beta firmware version 4.18. I have not noted this issue before, but to be honest, I don't often use the low end of 80m in the course of my normal operation. I came upon this while looking for stations in SS CW this past weekend. Anybody else seen this behavior? I don't know if this has anything to do with the issues experienced with 4.18, but I thought I would report it to make sure all the information is out there. I too have found that the transmit audio parameters that I normally used with 4.14 now sound a bit distorted with 4.18. I ALWAYS install EVERYTHING ( check all the boxes) on a firmware update, not just the portions that have changed, as suggested by Eric in his previous email. I have a direct RS232 connection from a "real" com port on my computer, through a data switch between my MicroKeyer II and said com port that I use to delegate what serial connection sees the radio's com port. I will be backrevving to 4.14 tonight, but kept 4.18 installed for SS CW. The new APF, although rather ringy, was extremely useful in grabbing 15m ESP QRP signals during SS CW. I think it's a great first effort by Lyle. I'm sure further tweaking will ensue and as everything in the K3, it will just keep getting better. -lu-w4lt- K3 # 3192 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I also noticed this, but on 40m and I think on 20m. No 80m antenna this
weekend. Would not have connected it with the K3 but for your note. Rich NU6T On 11/8/2010 5:34 AM, Luis V. Romero wrote: > All: > > In SS this weekend, I noticed something "new" with my K3: > > When attempting to transmit a low power tune signal (I'm set for 10 watts > out on tune) below, say 3.520, the power out and swr meters begin to > oscillate wildly. Going above 3.520, everything looks and works normally. > > If I key the transmitter using the TUNE function (press and hold XMIT), then > sweep the VFO below 3.520, the rig transmits fine at any power level but > does not receive (see below) until I move the vfo, whereupon it starts the > oscillation again. > > Listening on the receiver, when I tune below 3.517.70, the receiver stops > hearing anything on the band and what sounds like distorted voice audio from > a local Broadcaster is heard. I have a 50kw AM Broadcaster 5 miles away on > 970kHz, BTW, its their audio that I'm hearing. Its completely > unintelligible, but I can correlate that it's the same audio when they stop > modulation or go to commercials. Immediately when passing 3.517.70 going up > in the band, the receiver returns to normal amateur band reception, and the > distorted audio goes completely away. I have made a recording in case > Elecraft wants to hear what this sounds like. > > Tested this on SSB and CW, and find that the change to distorted voice audio > happens at 3.517.70 on cw, 3.519.30 on LSB and 3.516.30 on USB. This switch > point appears consistent, as I have repeated it several times. I don't have > the NB or NR on, and turning these on don't change the result. > > This is with K3 # 3192 using the recalled beta firmware version 4.18. I > have not noted this issue before, but to be honest, I don't often use the > low end of 80m in the course of my normal operation. I came upon this while > looking for stations in SS CW this past weekend. > > Anybody else seen this behavior? > > I don't know if this has anything to do with the issues experienced with > 4.18, but I thought I would report it to make sure all the information is > out there. > > I too have found that the transmit audio parameters that I normally used > with 4.14 now sound a bit distorted with 4.18. I ALWAYS install EVERYTHING > ( check all the boxes) on a firmware update, not just the portions that have > changed, as suggested by Eric in his previous email. I have a direct RS232 > connection from a "real" com port on my computer, through a data switch > between my MicroKeyer II and said com port that I use to delegate what > serial connection sees the radio's com port. > > I will be backrevving to 4.14 tonight, but kept 4.18 installed for SS CW. > The new APF, although rather ringy, was extremely useful in grabbing 15m ESP > QRP signals during SS CW. > > I think it's a great first effort by Lyle. I'm sure further tweaking will > ensue and as everything in the K3, it will just keep getting better. > > -lu-w4lt- > K3 # 3192 > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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