[RFI] A source of RFI

Tue May 30 12:16:45 EDT 2017

On 30 May 2017 at 6:20, Roger (K8RI) wrote:

> I know this sounds trite, but get a good computer.

I've got one. I build all my own computers (6 in the house so far) and always use top-notch 
components.

>  I'm running two 
> monsters in full size, steel tower cases within 3 feet of the rigs, USB 
> cables and standard serial cables (com1 and com 2). I have no 
> interference and no chokes on any of the lines.  The 75/40 sloping 
> dipole is about 60 feet from the computers.  O
> Desktop computers (PCs) typically use plastic cabinets and inexpensive 
> power supplies. The same goes for network interface cards.

Agreed.

> It's often not just the cables that radiate, but the computer itself 
> with the plastic cabinet makes for no attenuation to signals from inside 
> the computer.

Yes. Mine are all steel.

> Jim Brown (K9YC) has an excellent page on grounding and choking, but 
> with plastic cases...who knows.

Exactly.

> Antennas are 60 feet of more distant, but a fire in the RX coax 
> connector doesn't hear the computers either.

My antenna (the only one I presently have) is at least 50 feet from my transmitter/shack.

It appears that all my present RFI is coming from the monitor. I'll get that fixed later this 
week.

Ken W7EKB

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