[RFI] QST Article Ignores RFI

[Jon Ogden]

on 2/1/02 1:18 AM, Pete Smith at n4zr@contesting.com wrote:

> Whatever one thinks of the editorial wisdom of devoting so much space to
> this topic, I was astonished that the article contains no mention of inward
> or outward RFI, which has been a major preoccupation on this reflector over
> the years.  Selection of cases, power supplies and certainly monitors for
> the hamshack should certainly take RFI into account, but there's not a word
> on the subject there.

You know, I tend to ignore knuckleheaded articles like this normally.
However, this one caused quite a stir in our local contest club.  Just when
this article came out with virtually nothing to do with ham radio, the ARRL
announces that they are considering removing contest line scores from QST.

And then to hear that it talks nothing about RFI - what a joke.  I just had
a problem here with my computer that I was able to solve, and the RFI
problem was rather easily explained.

A few months ago, I interfaced my radio and the sound card of my computer.
The problem was, on 20m, I'd get RF into my audio really bad.  I think I
even posted here about it.  Well, I kinda forgot about the problem since I'd
not been operating all that much over the past couple months.  Last night I
sat down to work VP8GEO on 20m phone.  Well, let's just say it was really
bad.  He could hear me but not copy my real well.  I figured I'd just try to
work him, but it was apparent that he'd busted my call.  So I ripped the
cables to the computer out of the audio in/out jacks and called him again.
He thought I was a completely different station!

So then I figured I'd spend some time to find the problem.  So I plugged the
radio back into the computer and started digging.  Oh, my, I had the audio
out jack of modem plugged into the sound card's modem input.  I removed that
jumper cable and viola! no more RFI.  All the RF was getting onto the phone
line and subsequently the modem and then the sound card.

Now, I wonder how many people have never stopped to think of that.  I sure
didn't until I dug in there and started looking.

Now that's practical, computer related RFI solutions.

73,

Jon
NA9D