[TNham] 2 meters and cable channel 18 interaction

[Gary Pearce KN4AQ]

Cable Channel 18 lies smack on top of the two meter ham band.  The video 
carrier is 145.25 MHz, and the video channel goes up about 4 MHz from 
there.  So filters, stubs, notches, etc. won't help.

What DOES help is making sure the cable is a closed system, the way it's 
supposed to be.  You should not be wiping out your neighbor's TV.  (Do you 
wipe out your own TV?).  If the cable system is working right, you might 
see some interference bars when operating an HT in the immediate vicinity 
of the TV.

If your neighbor is cooperative, you can help him check all the connections 
to make sure they are tight.  Look for the cable entry to the house - 
there's probably a junction box with F-connectors.  Look anywhere the cable 
is split to go to several rooms.  You might find an amplifier that's not 
helping.  If there is an amp, see if a passive splitter does the job 
without making the video noisy (especially on the higher channels).  Check 
the backs of all the TV's to see if the connections are good.

By all means, contact the cable company.  It might take a while to find 
someone who knows what they (and you) are talking about.  They are legally 
obligated to clean up any interference out of the cable system, and have an 
obligation to their customers to clean up any problems with your signal 
getting into the cable.  Try to at least start with a positive, cooperative 
attitude, even if you aren't met by one.  If you're hearing strong signals 
on 145.25 all over town, it sounds like they have some maintenance to do.

If you get no cooperation, document everything and send it to Riley.  He'll 
probably send them a gentle reminder on FCC letterhead.  That may get their 
attention.

73,
Gary KN4AQ

At 04:20 PM 1/4/2004, you wrote:
>When transmitting on 2 meters anywhere on the band I am causing my 
>neighbors tv to blank out on channel 18 which for some odd reason is the 
>channel he watches 24/7. On 145.250 in Harrogate driving around I get S7 
>and S9 signals from cable TV leakage. The cable company is Communicom in 
>Tazewell. What are the odds they will correct this? Any help or 
>suggestions would be appreciated. I have told my neighbor to call me 
>anytime this occurs and I would be polite enough to curtail my operating 
>but lately he is complaining that I cause problems 2 or 3 times a week. He 
>doesn't understand that I am on 2 meters daily. He asked me how come I 
>didn't use other bands and I tried to explain that 2 is used by locals and 
>one of if not the most popular amateur bands. Anyway it's getting 
>frustrating for him and me both. I did send him on of the articles on the 
>ARRL website explaining this problem and the responsibility of the cable 
>company but haven't heard anything back. I suspect that any chokes or 
>filters will not cure this due to horrendous leakage.
>ED AND CARRIE YEARY  W4TEY and W4CAY
>325 CUMBERLAND DRIVE
>HARROGATE, TN. 37752-6942
>
>
>
>--- StripMime Report -- processed MIME parts ---
>multipart/alternative
>   text/plain (text body -- kept)
>   text/html
>The reason this message is shown is because the post was in HTML
>or had an attachment.  Attachments are not allowed.  To learn how
>to post in Plain-Text go to: http://www.expita.com/nomime.html  ---
>_______________________________________________
>TNham mailing list
>TNham@mailman.qth.net
>http://mailman.qth.net/mailman/listinfo/tnham


+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Gary Pearce KN4AQ
Editor, Repeater Journal
SouthEastern Repeater Association
116 Waterfall Ct.
Cary, NC 27513
919-380-9944
kn4aq@sera.org
www.sera.org
AOL/Yahoo IM: KN4AQ
(send e-mail to be put on my "buddy" list)