[TowerTalk] Low Pass Filters: Are They Of Any Use Today ?

[Steve London]

On 4/16/2012 12:20 PM, Jim Brown, K9YC wrote:
 > Given that the vast majority of TV's are on Satellite or Cable, is their
 > anything to gain by sticking a Low Pass Filter in the Transmission Line ?

 > Put very simply, NO. And even if a TV is on an outdoor antenna, it's
 > hard to find a good reason for an LPF. Since the final shutdown of
 > analog TV several years ago, nearly all broadcasters have abandoned TV
 > channels 2-6, so 174 MHz is the lowest frequency still in use in 95% of
 > North America, and the majority of TV broadcasters are on UHF.

As a first-order approximation, Jim is correct.

However, the low-band VHF channels have not been totally abandoned. There are 
even new applications for use of these channels. W9WI's web site has a wealth of 
information on USA and Canadian TV channel allocations (www.w9wi.com).

73,
Steve, N2IC