[Elecraft] OT: RFI from Modern Furnaces

[Jim Brown]

On Thu, 4 Mar 2010 08:47:43 -0800 (PST), Don Nelson wrote:

>My question to the group is: was I
>lucky? The furnace control has a very nontrivial computer control and could
>cause plenty of noise. It would be nice to think that the designers of
>furnace control systems are sensitive to RFI radiation issues.

The most likely source of RFI on the HF bands would be a variable speed motor 
controller. These are essentially switching power supplies driving square 
vave generators that are pulse width modulated to control motor speed. If you 
had that problem you would kiow it. Big time.  :)

73,

Jim K9YC