[RFI] New RFI source for me...

Dave Cole dave at nk7z.net
Sun Jul 24 13:54:59 EDT 2016

On Sun, 2016-07-24 at 12:52 -0400, Michael C Martin wrote:
> FYI to answer a couple questions.
> The transformer has a metallic contact that opens when it gets hot
> (this is to keep it from over-heating to the point of burning). As it
> gets hot the gap opens and expands. Eventually it's too large for the
> arc to jump the gap and stops. As it cools the contact snaps shut and
> starts to heat up again. Once hot, the gap starts to open again and
> the process repeats. This is typically more active during the hotter
> times of the day. However that can change depending on where it's
> mounted. The can be on the inside or outside of a breaker panel, or
> mounted to the side of the junction box that holds a ceiling light.
> Sometimes very difficult to find but these devices are a fire hazard
> when active!
> I'm going to be in my garage for the next several hours if I can
> assist call me.
> My diagnosis is based on very little info and only going on the sound,
> so it is a guess!
> Michael C. Martin
> RFI Services
> PO Box 411
> Traceys Landing, MD 20779
> 240.508.3760
> mike at rfiservices.com

Hello again Mike,

Thank you for the info.  I think I was unclear in my description-- the
device in addition to pulsing on and off over a few seconds, also comes
on and goes off at the same time each day...  

73's, and thanks,
Dave (NK7Z)
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