[RFI] Pulse noise on 40

[K8RI (Roger)]

On 1/19/2011 8:16 AM, Gary Smith wrote:
> Cheapo caliber electric blanket maybe?
> Gary...wa6fgi
>
Unlikely as it's a discrete frequency ...more or less.  It appears to be 
a group of closely spaced pulses (digital?) about 3 KHz wide +/- that 
drifts through the pass band (set for SSB) in about 15 seconds +/-. On 
the scope it has the typical bell shaped curve with a rather broad peak 
with a slow roll off. It does *appear* to be an intentional radiator.  
It's appearance has been sporadic and as I'm usually on late I don't 
know about other times of the day. So far, its not been strong enough to 
pick it out of the blips on the scope, or to see if there are are more 
than one instance of it on the band at one time. It's mainly an 
annoyance but does cover up the weak ones.  As I run the legal limit I 
often get answers on 40 that are now down in the noise with the band 
appearing to fold up some where between 10 and 12 PM.  It doesn't go out 
completely but unlike last winter or even a couple weeks back where I'd 
hear both sides of of ZLs and VKs working Europe about the only think 
I'm hearing are very weak stateside at 1200 miles plus.    This past 
fall 40 was going long around 10 PM or earlier and staying that way 
until well after sunrise.

   I go out to the shop (My wife calls it the toy building) late in the 
evening and work on projects with the rig running in the background. 
That's probably why I get so little done, but am so familiar with 40.

73

Roger (K8RI)