[ForSale-Swap] VHF interference on digital TV signals

[Ronald Oberloh]

I am surprised you need an amp.  You didn't mention but I expect you have a high gain UHF TV antenna pointed in the right direction.   In Phx I get  over 50 channels with all the Tucson stations as clear as the local channels and they are over 100 miles away.  I do have an amplifier but it is after the digital convertor  to the TV.  

Ron WA0KDS 

--- On Sun, 10/26/08, DALE PARFITT <parinc1 at verizon.net> wrote:
From: DALE PARFITT <parinc1 at verizon.net>
Subject: Re: [ForSale-Swap] VHF interference on digital TV signals
To: "Larry Brown" <larryb13 at iglou.com>, forsale-swap at mailman.qth.net
Date: Sunday, October 26, 2008, 11:12 PM



 
 

 

  ----- Original Message ----- 
  From: 
  Larry Brown 
  
  To: forsale-swap at mailman.qth.net 
  
  Sent: Sunday, October 26, 2008 11:52 
  PM
  Subject: [ForSale-Swap] VHF interference 
  on digital TV signals
  

  Not a sale/swap topic but something many of us 
  out in the rural areas might be dealing with soon.  
   
  Since we do not have cable in our area and I 
  refuse to shell out the $$$$$ for DirectTV  I purchased two digital 
  converters. After several weeks of installing the boxes changing splitters to 
  1.2gig gold plate splitters,buying and installing signal boosters and other 
  fussing,cussing and fine tuning I've finally got TV most of the time(with 
  analog I get 10-12 stations,with digital setup I get 3-4 and only part of the 
  time but that's a story for another time.)
   
  Now that winters heading this way I've set 
  up the shack in the house and !&?#?? my 2 meter kills the TV signal 
  whenever I key up!  Kenwood TS-711a running 25watts or less(mostly 
  2-10w)going to a Cushcraft 11 element beam.  All TV connections have been 
  checked and weather-sealed. Same for radio transmission line. SWR checks 
  1.2-1.5 across the 2meter band @ 25w. A MFJ analyzer shows no RF leakage 
  between the radio and antenna.
   
  Any thoughts on the next steps? By the time Feb. 
  19th rolls around I'll have experienced almost every problem possible with the 
  DTV conversion I'm thinking!
   
  Thanks for any input and if anyone has not 
  started setting up their converter box yet start soon. No matter what the ads 
  say,it's not "just hooking up a box" if you live 30+ miles from  
  town.
   
  Larry
  KG4ZAR
  
  Hi Larry,
  Although you don't mention the frequencies of the 
  TV channels- the likely culprits are the in-line amps. Unless you bought some 
  hi end amplifiers with excellent IP3 characteristics (Winegard, Channel Master 
  etc)- these amps are likely being driven into Xmod or IM dostortion.  
  Eliminate the amps and connect one TV directly to the antenna (w/o splitters 
  and their loss). If signals are now OK, build a 2M trap and insert it on the 
  input side of the amps.
   
  Dale W4OP______________________________________________________________
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