[KYHAM] Lexington hams help track down interference to KY EM repeater...

Sat, 07 Jun 2003 10:24:09 -0400

         The following is from Bob Stephens, KY Emergency Management 
Telecommunications Manager and Ron McKnight a communications technician for 
KY EM.  He asked me to post it to KYHAM.
         For those not familiar with the incident, there was a signal 
interfering (sometime making it unusable) with a KY National Guard and 
Emergency Management repeater in Lexington.  After several weeks of 
searching, Bob and Logan Weiler, KY EM Area 13 Manager contacted me to put 
together a crew to help isolate the signal.  There are a group of Lexington 
hams who regularly "fox hunt" for fun and fellowship.
         On behalf of KA4KYI, KG4LFP, KG4TND, KQ4ZZ, N4MOM, and myself we 
were honored to put that experience to use for a serious purpose.  Thanks 
for asking us to help!!!

73, Pat Spencer, KD4PWL

>From: "Stephens, Bob L - (KyEM)" <[email protected]>
>To: "'Pat Spencer, KD4PWL'" <[email protected]>
>Date: Fri, 6 Jun 2003 23:57:55 -0400
>X-Mailer: Internet Mail Service (5.5.2653.19)
>
>Please resend this to KYHAM please.  Thanks for great support.
>
>This is a note to me from Ron McKnight regarding the results of a 6 week 
>"FOX Hunt" or search for stray radio frequency energy causing major 
>problems with the Lexington Repeater.  Many of you may recall that this 
>problem shut down communications to the EKU Rescue School.  The RF problem 
>has been solved.  We located the source of a radio transmission on 143.00 
>MHz that was causing havoc with the Lexington Department of Military 
>Affairs/Emergency Management Repeater.
>
>After a few weeks of "dedicated" day and night searching, the noise 
>culprit affecting Lexington tower has finally been found and resolved. As 
>it turns out, we had a quite a few noise locations on 143.000 throughout 
>Lexington. This past weekend the ares club (LEX) found yet another source 
>for the signal in the 200 and 300 block of Maxwell.
>
>Yesterday Logan Weiler and I went and isolated that particular signal to 
>what we felt like was the probable house (UK). This morning I returned 
>back and found for certainty that the house in question was the definite 
>culprit of the noise by using a Spectrum analyzer and a yagi beam antenna. 
>But we still had to find what and where in the house was making the noise. 
>With UK staff allowing me to gain entrance, we found that almost all the 
>electrical outlets in the house carried the noise as well as all the T-1 
>connections in the house.
>
>After several hours of searching, the strongest signal I had seemed to 
>come from an alarm wire box. The security people came and unhooked the 
>alarm in the basement, but the noise continued. A few moments later, they 
>began to turn off breakers. The noise still continued. Then it stopped all 
>at once. Unknown to me, another staff member had removed the cover of the 
>alarm box and unplugged the alarm transformer from the wall socket. The 
>noise stopped.
>
>The guilty culprit was a little modem (about the size of a Zippo lighter) 
>tied into the Computer Hub line to notify Campus security dispatch. We 
>later found that the house has a slight electrical ground problem. When it 
>rains, the noise was never there because the ground outside the house 
>would be damp enough to shunt the offending signal. We mainly heard on 
>weekends and Holidays because that is when the alarm was on. Recently, the 
>system had quit working, so no one ever turned off the alarm, thus it was 
>ongoing all the time. Many thanks to LEX ARES club, Logan Weiler, and to 
>all of you had had the patience of waiting why we chased down a tiny 
>little modem in a City the size of Lexington. Thanks again, Ron
>
>Ron McKnight
>COMMUNICATIONS
>KY Division of Emergency Management
>Frankfort KY 40601
>Office 502-607-1617   Cell  502-330-2612
>
>Bob Stephens
>Communications Branch Manager
>Kentucky Emergency Management
>Office Phone    502-607-1617
>Office FAX      502-607-1620
>Cell Phone      502-330-0412
><http://kyem.dma.state.ky.us/>http://kyem.dma.state.ky.us/