[Elecraft] Elecraft SSB Net Announcement

[Jim Wiley]

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.
>
>