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Re: [RFI] RFI to TV

To: Patrick Dyer <pjdyer@swbell.net>
Subject: Re: [RFI] RFI to TV
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Thu, 09 Dec 2010 13:59:09 -0500
List-post: <rfi@contesting.com">mailto:rfi@contesting.com>

On 12/9/2010 6:50 AM, Patrick Dyer wrote:
> 145.25 is the CATV Ch 18 (Ch E) NTSC video carrier frequency, and on an
> (FM) HT it will sound pretty much like unmodulated dead air.  The audio
> for that is 4.5 MHz higher (so out of the 2m band).  It's the only basis
> that the FCC will accept a formal complaint from hams for CATV egress
> RFI situations.
Not sure I understand the wording of that.

If you can hear them, they can hear you.  Years ago...actually many 
years ago...Bout 81, or 82 I lived in Alma MI.  I was driving home and 
noted some interference on the 2 meter rig.  Tuning to 145.25 I found it 
full scale.  Much of the East and North side of town (the only area I 
drove in) were that way.   As I drove right by the 
receiving/distribution center/office on the way into town I stopped for 
a chat.  When I walked in I keyed the HT and their set went dark.  The 
receptionist immediately called service. They weren't impressed as I was 
so close to the set. So, I asked them if this was the distribution 
center wasn't every one down stream seeing the same thing. They 
nonchalantly said "it's probably just this set" without checking.  
Sooo... I pointed out my car on the other side of the parking lot and 
suggested I try the mobile. A quick test, some one answered me and we 
started a short chat explaining what I was doing.  About that time I saw 
the guy come out of the office waving his hands.  I was dumping the 
cable system for the entire town.

Back inside I explained that there were quite of few of us living in 
town and that almost all ran as much power as I did because it was quite 
a distance to the repeater...which took another explanation.  At any 
rate we both figured if I could hear them they could hear me and so 
could any one down stream of the egress/ingress point.  When I came home 
the next day, most of my route was clean.  The next day most of the town 
was much better and within a week there was not a spot in town where I 
could hear them.  I did stop by the office and than them.

Of course if it's just in a house that's a bit different and 
particularly with an illegal tap. Had one of those across the road many 
years back.
OTOH with the telephone, I lost service one day, which was not uncommon, 
but this time they didn't find any problems outside the house which cost 
me $50.  A search found a unterminated run (behind the desk that held 
the rigs) with all the wires stripped and twisted together as neatly as 
if it had been on purpose. ... CAT!


Roger (K8RI)
>    I had to resort to that (thru the FCC Houston office)
> to get the local CATV moving on what turned out to be a classic case of
> "dog-chewed cable" on adjacent property in early 1991.  The CATV work
> order/ticket actually had that as a checkable item of cause (it being so
> common)!  The CATV coax was rerouted to minimize a reoccurrence.
> All the numerous CATV audios between 130-150+ MHz are a pretty good way
> to ascertain/demonstrate egress since they are not broadcast (OTA) TV
> freqs and "stand out".   When the leaks were on OTA freqs such as this
> http://www.qsl.net/wa5iyx/images/833311.jpg could occur - Sept 1983 when
> our local Ch 4 was off (turned out to be an adjacent-east illegal tap,
> before TX had enacted any CATV theft-of-service statutes, "cured" by
> changing the 4-port in the pedestal in their yard to a 3-port.  BTW, the
> renters were evicted 2 mon. later.).  Needless to say, with that source
> at c. 20 ft away it really messed up my OTA TV reception. (And probably
> provided good CATV ingress for any of my VHF RF :<)
> 73, Pat - WA5IYX
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