I do wish I'd read this last one more carefully before posting, what I had intended to say was that the noise only disappears (but only in cw/ssb modes) below FC = 0.81 kHz.
On 17/11/2010 22:28, "Stephen Prior" <[email protected]> wrote: > Further to my last posting, I observe now that the appearance of the 'qrm' > depends upon the filter and shift settings, what is observed to be a problem > in AM mode completely disappears in cw/ssb modes, for example this occurs at > and below FC = 0.81kHz. > > Stephen G4SJP > > > > On 17/11/2010 22:05, "Stephen Prior" <[email protected]> wrote: > >> In tuning above 7.385MHz, listening to broadcast stations on AM, I noticed a >> very strong and broadband interference extending to just above 7.500 MHz. >> >> At 7.385MHz on AM mode I hear a relay click in, and I'm assuming that this is >> the K3 changing over to the KBPF3 which I have installed. Looking at the >> P3's >> display, the spectrum which is hf of 7.385 MHz is completely clear of such >> 'qrm' until the VFO goes above 7.385 MHz, and then the qrm appears about 35dB >> above my noise floor, not only above 7.385 MHz, but extending below it to the >> extent that the P3 will show. Since this is not even observed on the P3 >> (with >> its maximum span set) until the VFO is tuned above 7.385 MHz, I can't help >> but >> to think that this is an unexpected artefact. Removing the antenna clears >> this completely, so it is not internally generated. >> >> But what is causing it I wonder. I have never noticed this effect before. >> Since it only occurs above a set frequency and then is apparent below that >> frequency too, to my mind it has to be a fault with the K3 that I haven't >> observed with any previous firmware version. I am running with latest beta >> for both the K3 and P3. >> >> 73 Stephen G4SJP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
