[RFI] Ethernet RFI UPDATE

[WA3GIN]

Hi Folks,

I've been having success troubling shooting the Ethernet connection problem.  Apparently, I was indeed getting RFI to the Ethernet extender box.  I've had to go to some great lengths to reduce what was "not" measurable RF floating around.  

Installed common ground point for all active devices:

-  grounded HOST SERVER power supply
-  grounded Ethernet box
-  grounded shields on Cat 5
-  grounded UPS
-  rack,radio, linear, 12VDC PS (were already grounded)
-  grounds used for telco/CAT5 surge suppressors now common with all other grounds in rack
-  toroidal chokes added to CAT5 output from Ethernet box, CAT5 input, 5vdc input 


I don't know if this next change has created was worth doing or not but I took the CAT5 twisted pairs of telco wire that unused in the 6 pair trunk line running between the barn and house (1,000ft) and terminated them to ground at both ends of the line.  My thinking was that if these pairs were  not terminated they might act as receive wires and re-radiate RF into the active circuit pair. I know this is a stretch considering the cable is shielded and buried.  It doesn't appear to have hurt performance of the Ethernet circuit.

Before making these changes a 5 watts transmission using CW, even into a dummy load would cause the Ethernet circuit to loose sync. 

Since the changes to the environment the circuit appears to be running faster and is uneffected when key down with 100 watts of CW to the outside antennas.No sign of problems.  So, perhaps there was RFI or the "PIN 1" scenario was causing a higher bit error rate.  It is hard to say without test gear.  After lunch I'll do the big test with the legal limit on CW. 

What led me to this approach was the excellent inputs from members of this reflector  and the fact that the Ethernet box uses RF similar to BPL in the 7-10MHz range to extend the connection over twisted pair telco wires up to 1500ft for the modle I'm using.  Transmitting on 30 and 40m are the only bands where I had a problem.

Anyway, we're making progress.


73,
dave
wa3gin