[RFI] Line noise update

K4RO Kirk Pickering k4ro@k4ro.net
Wed, 8 May 2002 11:11:50 -0500

Since not everyone was at the meeting, I thought I 
would give a brief update on the line noise at K4RO.

Things are looking up.  The folks at NES have been
responsive to my calls. They have had trucks out here
looking for and correcting problems.  Here is what
I've learned so far.

1) Give the power company actual pole numbers whenever

If you want to help your power company as much as 
possible, give them actual pole numbers.  They can
be much more responsive when they don't have to spend 
their time looking for the noise.  If you can identify
the actual pole numbers, your chances of a bucket truck
appearing the next day or two are highly improved. So, 
how do you find the actual poles?

2) Beg, build, borrow, or steal an RFI sniffer.

I have been using AA4NU's RFI sniffer.  It's a homebrew
3-element handheld yagi with a 135 MHz AM aircraft receiver
attached in a shielded fashion.  With this wonderful tool,
I was able to easily zero in on the troublesome poles, and
sometimes could even identify exactly where on the poles
the noise was coming from.

3) Find a way to "remote" your HF RX audio to a VHF handheld.

This is a great way to listen to your actual HF receiver and
antenna system as you go around knocking on suspect poles with 
a sledgehammer.  WAIT a minute - a sledgehammer??  You're not 
supposed to do that!?!  Well, that's exactly what the guy at 
NES told me to do, believe it or not.

I simply chose an unoccipied simplex frequency on 222 MHz FM,
then placed my HF RX speaker on top of the mic's PTT switch.  
Using my trusty old IC-3AT handheld, I could "carry" my HF RX 
audio all over the neighborhood while I checked poles.  After 
years of suffering with line noise, there's nothing quite like 
the feeling of hearing your receiver go totally quiet with the 
mere tap of the sledgehammer!

I still have more poles to fix, and I'm sure it will be an
ongoing maintenance issue.  However this month feels like real
progesss. There's really nothing new here, and the books will
tell you the same thing.  Just thought I'd give a progress report,
and point out that these problems can be addressed with patience
and the right tools.

Thanks to AA4NU and K3CQ for the loan of the sniffers.  
It's time to build one for myself, and return theirs.

Line noise can really take the fun out of your contesting.
Good luck to all who are dealing with it.

-Kirk  K4RO