[RFI] A source of RFI

[Kenneth G. Gordon]

On 29 May 2017 at 17:50, chas cartmel wrote:

> Could be the monitor. In my case a new monitor caused considerable RFI.

I think that is the case here. I am going to attack the problem from that end first.

> I
> exchanged this for another in another room and RFI was greatly reduced.
> As with all leads I use ferrite clamp-on chokes on PC connections and any
> power leads to and from intermediate power packs such as wall warts and
> laptop / monitor external PSUs.

Yes. I find I must do that too, but also to keep RF in the shack from getting into the 'pooter or 
peripherals.

> All my equipment, rig PC and monitor, is
> connected to a single earth point in the shack which in turn is connected to
> earthing rods external to the property.

My earth ground here is poor, but I intend to remedy that asap. 4 ea 8' copper-clad steel 
ground rods, separated by 8', driven to within an inch or two of the surface of the ground, 
connected together by size 00 welding cable, then into the shack. about 15 feet, with 00 
welding cable.

> I am aware that somebody on this site stated that earthing in this manner to
> reduce earth loops was not necessary as earth loops did not exist,

Yes. I remember that...

> however
> it seems the RFI in my case had not read the text book and decided to reduce
> itself anyway.

When I installed even the poor ground system I have now, my results were about the same 
as yours: noise was reduced.

> Hope you get it sorted.

Ha! Me too! Thanks... :-)

Ken W7EKB

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