Hi Jim, That makes sense. I was thinking a bit and realized most computer motherboards have a 14.318mc oscillator in them. Then as you said the color burst freq x4 and that makes a huge mess out of that freq and near by. 20m was up & down and the solar conditions are terrible this weekend compounding the problem of having only 15w to work with. At least one person heard me and repeated my callsign so I hope I got checked in...hi hi...
-- Mike WE0H K2 #6698 SKCC #5446 Jim W wrote: > > Mike et al - > > > It might be good to check to see if you aren't doing it to yourself. > 14.318 divided by 4 is 3.579 MHz, the "color burst" frequency used by > millions of consumer devices as a reference frequency, and not just TV > sets. I have heard carriers on or around that frequency with > strengths up to and including "S9" for literally years. Harmonics > from poorly designed or shielded oscillators in TV sets, computers, > clocks, DVD players, VCRs, microwave ovens, game players, fax > machines, printers, telephones, toys, medical devices, and many more > items have polluted this frequency for at least 20 years. Just now I > checked and can hear at least 5 separate "sources" in a casual > check of the frequency - and those are just the "loud ones" from a > random beam heading. I am sure there are dozens more underneath the > louder ones. . > > > The sources are so ubiquitous that it is virtually impossible to > escape them no matter where you live. The signals that you are > hearing are probably not the same ones that another ham in the next > state is hearing, but there are so many of them that it is unlikely > anyone can escape them. > > They are part of the reason for that FCC warning about "Operation this > device may cause interference to nearby radio ant TV receivers ....." > (I am paraphrasing here) that you see on so many consumer electronics > devices. > > > One reason your DSP may be having trouble eliminating the carriers is > that there are usually several on slightly differing frequencies. The > crystals aren't all that accurate in some devices, and by the time we > get to the 4th harmonic, differences of a few tens of Hertz to several > hundred Hertz are common. Most of these oscillators are not in some > type of circuit that is phase locked to a master source, as is the > case for some TV broadcasts. Most of them are "free running" in the > sense that all they have to be is "close enough" to perform the task > at hand., > > > - Jim, KL7CC > > > > Mike-WE0H wrote: >> That carrier on 14.31800mc is nuts loud in Minnesota. I tried to >> check in but only one station heard me and repeated my callsign. Even >> the DSP won't wipe that screaming carrier out. ______________________________________________________________ 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
