[Elecraft] RF into K3 via serial port?

[Kevin Stover]

Ditto on the K9YC info.
I have an resonant 80m dipole strung right over the house at about 60'.
I was getting RF on nearly everything in the shack.
Two of the K9YC chokes wound 5 turns of RG-213 through a stack of 5 Mix 
31 toroids, one at the feed and one at the entrance knocked it back by 
90% with only the computer being left.

The secret to getting it gone from the computer was the idea of using 
CAT5/6 twisted pair networking cable for all computer connections. 
Especially the serial ports I installed in my home brew computers.

The rest of the house was relatively easy and as it turns out the 
LCD/LED TV's were the easiest.

On 4/5/2014 7:57 PM, Jack Brindle wrote:
> What kind of cables are you using between the PC and the K3? If shielded, are you sure the shields are connected to the DE9 shell at both ends? The RF _could_ be getting into the conductors and causing problems in the computer/serial card and not actually the K3. The computer could then be asserting or negating the handshake lines, killing K3 transmission, or causing the software to send a stop data transmission to the K3. We have found the usually the RFI problems are outside of the K3.
>
> Be sure to read the RFI info at K9YC’s site. It provides a lot of good details about the problems of RS-232 cabling and connections. Also, even though you may not detect “hot RF” in the shack, it just might be there. RF likes to ride on the outside of the coax going from the antenna to the radio, causing problems. Thus good choking is needed to eliminate the problems. Again, K9YC’s document has some really good info.
>
> http://www.audiosystemsgroup.com/K9YC/K9YC.htm
>
> 73!
>
> Jack B, W6FB

-- 
R. Kevin Stover
AC0H
ARRL
FISTS #11993
SKCC #215
NAQCC #3441