[CQ-Contest] Keyboard RFI problem solved

Bill Turner dezrat1242 at ispwest.com
Wed Aug 17 23:14:44 EDT 2005

I've been playing around on 160 meter RTTY the last few days and had a 
problem with the keyboard freezing when the power exceeded a certain level, 
around 1kw output. I tried three different keyboards and enough ferrites on 
the keyboard cable to anchor a battleship but no luck. In fact, no 
improvement at all. And that got me to thinking: Why didn't the ferrites help?

Perhaps the problem isn't in the keyboard at all, but rather the connection 
inside the computer, since all three keyboards had exactly the same 
sensitivity to the power level, and adding ferrites made no change in the 

Long story short: I happened to have a USB keyboard laying around, so I 
tried it. Presto! Problem solved, perfect operation at any power level. I 
can't say this would work in every instance, but it's worth a try. The 
keyboard is just an inexpensive one made by AOpen.

One problem with this is the BIOS does not recognize a USB keyboard, so it 
must be set to not stop on keyboard errors, and if you want to hit DEL to 
set the BIOS, you have to temporarily plug in a regular keyboard.

Something to keep in mind if you have keyboard RFI problems.

Bill, W6WRT

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