# what is on this broadcast antenna?



## DBSPaul (Mar 26, 2002)

We'll be moving soon to a new home, and about one mile away is a broadcast antenna. I know who the owner is from GPS coords and some help I got back here awhile ago, but at the top are some devices I've never seen before.

Given that I'm using a super-high gain UHF antenna and preamp to try and eek out the miniscule low-power Denver stations, I just want to make certain this isn't something in the UHF band that will cause headend overload on the preamp..

Hopefully I got the picture to upload. Sorry for the res - it was a cloudy day and all I had with me was my 3MP point&shoot.


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## kenglish (Oct 2, 2004)

Looks like an 8-bay FM antenna. 

FM is often a problem, causing amplifier overload in the VHF band. Be sure your antenna and amp are not capable of passing the VHF bands.....you may want to add a tuneable FM trap to the input of the preamp. The station's engineer might have a trap already available....sometimes a station will offer them, if the station is very near a residential area and has had "front end overload" problems with nearby receivers.


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## DBSPaul (Mar 26, 2002)

kenglish said:


> Looks like an 8-bay FM antenna.
> 
> FM is often a problem, causing amplifier overload in the VHF band. Be sure your antenna and amp are not capable of passing the VHF bands.....you may want to add a tuneable FM trap to the input of the preamp. The station's engineer might have a trap already available....sometimes a station will offer them, if the station is very near a residential area and has had "front end overload" problems with nearby receivers.


Hmmm. This is not welcome news, as I do have a VHF antenna for the NTSC stations (since Denver doesn't have its act together on ATSC). I do have custom filters to knock out 54MHz and below (HAMs), 120-168MHz, the preamp has a FM filter on it, and a 107.9MHz notch filter for a fairly powerful FM station that will still be in the back lobe of the VHF antenna.

However, at least it isn't something I have to worry about for my UHF setup, which placing *any* filter in the way introduces enough loss that I lose the ~25% of the time I can pull in the NBC station in HD.

The next worry will be the person two houses up who has a fairly significant antenna (higher than his 2-story house) in his yard - here's hoping he has his HAM rig set up properly, otherwise he'll blow out everything each time he keys his mic.


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