Sounds like a coil, solenoid, relay, etc. being activated and doing its
thing. Humidifier opening a vent, etc. Solenoid turning water off and on
causing the inertia of the water to thump the water pipe when valve slammed
off?
73, Jim KG0KP
-----Original Message-----
From: RFI [mailto:rfi-bounces@contesting.com] On Behalf Of D C _Mac_
Macdonald
Sent: Sunday, March 30, 2014 3:08 PM
To: Gary@ka1j.com; rfi@contesting.com
Subject: Re: [RFI] Thumper & not the rabbit
"HiFi" speakers have been known to thump in rhythm with the sending of CW
when the amp is OFF!
Not sure what is actually thumping, but the idea of finding a panel that's
doing it might be of value.
* * * * * * * * * * *
* 73 - Mac, K2GKK/5 *
* (Since 30 Nov 53) *
* Oklahoma City, OK *
* USAF, Ret (61-81) *
* * * * * * * * * * *
> From: Gary@ka1j.com
> To: rfi@contesting.com
> Date: Sun, 30 Mar 2014 11:33:17 -0400
> Subject: Re: [RFI] Thumper & not the rabbit
>
> A couple of reasons, Main one is the 97 year old who lives here and
> gets scared and very vocal it will cause damage to the heating unit
> requiring replacement of the part and the loss of heat until the
> expensive repair is done. This is not an unjustified concern & demand.
>
> The other is I couldn't feel which part is thumping but more to my
> interest, why is it thumping, it's not a hum, its a loud thump. Some
> electronic component is creating slamming in a way it never does in
> normal operation.
>
> I need to find the problem and address that.
>
> Gary
> KA1J
>
> > Why not figure out exactly which panel of sheet metal is thumping, and
then either pull it tight by attaching a thin cable to it with a sheet metal
screw and tying it off to a wall, or pushing against it by wedging a 2x4 or
something against it?
> >
> > Chris
> > KF7P
> >
> >
> >
> >
> > 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
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|