Hi Russ, Your response made *very* curious so I checked out my own K3S. I can confirm the two switchover frequencies you mention (1700 and 3300kHz), but observe at most a couple of dB change when crossing the boundaries. I use an external panadapter (LP-PAN/NaP3 connected to IF-OUT) so I can easily see the same stations and noise while tuning across the boundaries. On the 1700kHz boundary the signals are a couple, maybe 3dB stronger when below 1700kHz. So it sounds to me that the filters in your KBPF3A are not being switched in when it is supposed to be used. The KBPF3 needs to be enabled (set to "nor") in the configuration menu. Have you checked that?
Hmm, I neglected to carefully read the last part of your post. It sounds like your KBPF3A might be working above 4210kHz so may be just the 2 lowest bands are defective. If you look at the schematic you see that those two bands use the same filter but with some components switched in and out by another relay (K2). So that could narrow the problem down to one relay (K1) not operating. Is this a *new* problem or has it been like this since you got the K3 or installed the KBPF3A? Knut - AB2TC Elecraft mailing list wrote > Hi Ben: > You had me curious with your request. I started to check my KBPF3 > (modified to the "A") and noticed something that now bothers me. I tried > going down from 160M and it appears that the switch over to the AM > broadcast band occurs precisely at 1700,000 Kc. When I tune to 1.699999 > the relays click. But the anomaly(?) I am seeing at the switchover point > is a big drop in the signal level. At my QTH during the daytime the > nominal noise level at 1700.000 Kc is about S7. When I switch to 1.699999 > the noise level drops to S2. At the high end the switchover occurs at > 2109.999+ with a drop in the noise level from S9+10 to S3. I don't use > the K3 for listening to AMBCB but only in the case of checking my 160M > receiving loops with some stations high in the AM Band. I checked on 80M > and got similar results. At the low side the switch occurred at 3299.999 > with a drop in the noise level from S5 to S2. On the high side the > switchover occurred at 4209.999+ but here the noise level increased from > S4 to S6. I don't know if this helps you any on at least these 2 bands. > If I get the time I'll try to check the rest. Now I'm bothered by the > changes in signal levels at the switchover points (ignorance is bliss). > I wonder if anyone else has ever noticed this or do I have an issue with > my KBPF3? > > Russ, N3CO > On Friday, April 16, 2021, 12:39:28 PM EDT, w4sc < > w4sc@ > > wrote: > > Looking for details of switch over frequencies and expected performance > of the KBPF3A in its various bands, > > There is improvement in the BCB and below 500KHz with the KBPF3A enabled, > however the other SW BCB bands I have tried are lacking. > > Has anyone measured the performance of the KBPF3A? > > Ben W4SC > > Sent from Mail for Windows 10 > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto: > Elecraft@.qth > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to > erusst@ > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto: > Elecraft@.qth > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to > lists+1215531472858-365791@.nabble -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ 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
