[RFI] FW: [CQ-Contest] Follow-up on RFI and laptop - problem solved

[Tim Duffy K3LR]

-----Original Message-----
From: cq-contest-bounces at contesting.com
[mailto:cq-contest-bounces at contesting.com] On Behalf Of Barry
Sent: Monday, December 17, 2007 6:41 PM
To: cq-contest at contesting.com
Subject: [CQ-Contest] Follow-up on RFI and laptop - problem solved

Thanks for all the suggestions.  Problem is solved now and here's what I 
did:

1. Grounded the laptop to the station bus ground - I've always had 
grounded my desktops, but it was easy, attaching the braid to one of the 
case screws.  It required a little thought where to ground the laptop.  
I wound up using one of the 2 screw connections on the external monitor 
jack.
This alone let me go from 200W to about 1 KW before the CW acted back up.

2. Ferrites on the USB serial cable - no noticeable effect.

3.  0.01 bypass caps on all the inputs and outputs of my interface box,  
This is a homebrew box for CW, RTTY and voice keying.  It uses 4N33 
optos for switching and as I never had an RF problem before, I never 
bothered with the bypass caps.  That did the trick.  Full power out, no 
more problem.

Thanks again for the suggestions.
Barry W2UP

-- 

Barry Kutner, W2UP             Newtown, PA   

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