[RFI] FW: [K0USA-AKSARBENtalk] Traffic Signal RFI

Ed - K0iL k0il@arrl.net" <k0il@arrl.net
Sun, 7 Oct 2001 15:05:28 -0500

Has anyone else out there noticed this problem in other cities?
 de ed
-.-.  --.-   ....  .-  --  ...   -..  .   -.-  -----  ..  .-..   -.- 
           Ed Edwards    --    K0iL
 PO Box 375                        k0il@arrl.net 
 Elkhorn, NE 68022-0375       k0il@qsl.net
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-----Original Message-----
From:	Bill Jackson [SMTP:k9rz@radiks.net]
Sent:	Sunday, 07 October, 2001 9:37 AM
To:	Aksarbentalk
Subject:	[K0USA-AKSARBENtalk] Traffic Signal RFI

Since .94 is down, I have spent more time monitoring some of the other repeaters
while motoring around Omaha.  A couple of weeks ago, I started to notice a
pattern that when I pulled up to certain intersections in west Omaha, signals
would get rather noisey, even though they were 1/2 scale to 3/4 scale on
S-meter.  I noticed this effect particularly while listening to 146.82.  The
noise is almost pure white noise, not raspy like power line interference or
electrical noise.  I thought it might be coming from the computer in my Ford
Ranger, but could not make it happen in my driveway, so I guessed it was
something external to the truck.

Yesterday, I may have had a major break in the case.  I was sitting at the exit
from Home Depot on 144th street waiting for the light to change.  I noticed the
white noise was almost blanking out 146.82, even though the S-meter on the rig
was almost full scale.  When the cross walk lights on 144th Street changed from
a steady "Walk" to a flashing "Don't Walk", the noise level started pulsing in
time with the flashing of the "Don't Walk" signs.  The noise did not go
completely away, but was changing in level enough to notice.  Since the
intersection to Home Depot is new, I notice it has a new style of cross walk
lights that appear much brighter than ones using ordinary incadescent lamps.  I
wonder if these are some type of low energy, long life gas discharge lamps
similar to the ones that have been written up in QST that are known to cause

Have any of you also noticed this effect?  This could be a major problem for
public safety communications.  Imagine an accident at an intersection with these
lights installed and a policemen with the portable radio trying to communicate
to the dispatcher.

I plan on watching for this effect at other intersections to see if there is a

73 de Bill