[RFI] Thumper & not the rabbit

[donovanf at starpower.net]

Hi Gary, 

Can you share the results of the RF Exposure evaluation you are required 
to perform by the FCC regulations affecting your license? Your description 
of your antenna placement and your earlier comments about QRO makes 
it sound like you have a much more serious problem than "Thumper." 

QRO to a low roof mounted tribander presents serious RF safety issues 
every inhabitant of your home. FCC regulations that affect your license 
require that you inform every inhabitant and guest in your home about RF 
exposure safety of the risks they face. Furthermore, every inhabitant and 
guest must agree to accept their RF exposure risks. 

http://www.arrl.org/fcc-rf-exposure-regulations-the-station-evaluation 

73 
Frank 
W3LPL 

----- Original Message -----



> 
> On Mar 30, 2014, at 1:16 , Gary Smith wrote: 
> 
> Some interesting thoughts. It's for sure RFI that's involved and I am 
> ordering a fairly large quantity of ferrite clamps which I plan to 
> attach to each coax termination & origin in my system. I'll have some 
> left over to try and resolve things like this. 
> 
> The most mysterious part to me is how it is a thumping sound just 
> like a large sheet is energized in a kinetic nature and vibrating 
> against resistance creating a drum like sound using the enclosure as 
> the drum head. Very unexpected. The leads to the unit are pretty 
> tight and I think it would be a good idea to make loops of matching 
> zip cord through the ferrite snap-ons and solder them in series to 
> the existing control wires. 
> 
> This will be a good first step and then mention was made about the 
> unit being properly grounded. I haven't looked at that as it was 
> installed by a local heating company and I will have to be sure they 
> did that. 
> 
> The tribander is at arm level on the top of the roof of this 1 story 
> ranch and if it were higher, there would surely be less rfi to 
> contend with. Can't do higher at this time but I've been considering 
> hardline, I wonder if this would be of more benefit to reduce the 
> RFI? issues or if its the RFI getting into the equipment from wiring? 
> Still, there was a very marked improvement in thumping with that new 
> balun in line. 
> 
> Thank you for the attempts to help. 
> 
> 73, 
> 
> Gary 
> KA1J