900mhz Interference with TV

I recently did an install by mounting my connectorized 900mhz SM and Yagi on the same pole as a customer’s TV antenna because I needed the height. Unfortunately I evidently just made a major beginner’s mistake because now one of their TV stations will not come in unless the SM is powered down. I have not heard of this problem before. This is way out of band interference. Has anyone encountered this before? Does anyone have any ideas on how to fix it without necessarily moving the mount off the pole? I tried putting a plastic sleeve beneath the ubolt connecting my yagi so that it is not actually touching the pole but that was to no avail.


I would be curious to know what channel is being interfered with. And, which are not being interfered with. FYI channel 69 ends at 806MHz.

well, actually 3,6,and 13 are the only three that ever come in around here. 3 and 13 are always better than 6 and they do show some interference, it’s just not debilitating because their signals are stronger. My guess is just that my 900mhz signal is just being picked up to strongly and is overpowering the reciever. I wonder if there is some filter that you can put on the TV cable that would filter out out-of-band interference…

I have run into this problem numerous times. The only solution I have found is separating the sm from the antenna as far as possible. Also, put in a good word for sattelite tv.LOL

I have fallen victim to this before as well.

In an attempt to keep a customer happy, I colocated the 900 SM on the same mast as his UHF/VHF aerial. Having similar results to those previously reported, I now just avoid them all together.

You could try a low pass antenna filter.

http://www.hometech.com/video/atten.html. You probably want the 310260. This will pass 2-13 and filter 14 and up.

Also, check the cable and make sure the gound is good. More than likeley the connector has rotted and there is no ground connection from the antenna balun to the TV (or TV amp). Also make sure the connection from the balun to the antenna is not corroded or loose. Loosen the connectors and shoot some contact cleaner on it. (That should be billable time.)

They could also replace the cable. They are probably using dual shield. An RG-6 Quad-Shiled cable will offer better signal to the TV as there is less loss over the same length. (Also billable time).

As tjizzle says, might be 'bout time to step and get satellite.

Awesome. Thanks for the help! Good to know this is a common problem. I had considered that it might have something to do with the ground. I am thinking my solution will be to just try and avoid antenna masts from now on. It’s not a big enough deal to warrant replacing the cable and they probably won’t care to spend money on a band pass filter. They do have a satellite and they only use the antenna to watch local news from 8-9am and they don’t mind unplugging my sm. Your suggestions are duly noted though for future reference. :wink: