[Elecraft] Fwd: OT Mystery QRM Help (Video)

[David Ahrendts]

A bit more: I watched this mystery QRM pretty closely for an hour Friday evening as 20 meters closed for the day (by 6:30pm PST). The cadence of this noise changed. It slowed. Then faded away with the band. I’m scratching my brain to try think of a mechanical device that would create that kind of rhythm. And as always as I check 20 meters at 11am Saturday, there is no sign of the QRM. 
Will listen again late afternoon today. May experiment moving the DB-11 around to see if it is directional. 


> Begin forwarded message:
> 
> From: David Ahrendts <davidahrendts at me.com>
> Subject: OT Mystery QRM Help (Video)
> Date: January 22, 2016 at 6:16:36 PM PST
> To: "elecraft at mailman.qth.net" <elecraft at mailman.qth.net>
> 
> Stumped. Need your guesses. What is this mystery, rhythmically pulsing, urban S7 QRM:  https://vimeo.com/152779708 <https://vimeo.com/152779708>  
> 
> Factors: captured 5:30pm Friday (Sunset was 5:15). Densely packed Los Angeles neighborhood — could be next door or a block away. Occurs regularly at night or near dusk and not prime 20M day time. Occurs only on 20M. I’ve noticed it from Fall on to current Winter time.  Seems to be a mechanical device (pool pump?). 60-degrees falling to 50-degrees tonight -- a heater system? Eventually just fizzles away slowly. Elecraft K3S + P3, SteppIR DB-11.
> 
> David A., KK6DA (formerly KC0XT), LA 
>  
> 
> 
> David Ahrendts   davidahrendts at me.com <mailto:davidahrendts at me.com>   
> 
> 
> 
> 




David Ahrendts   davidahrendts at me.com