[Elecraft] Elecraft SSB Net Announcement

[Mike-WE0H]

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.