How to block RF channels?

General Discussion
1

Does anyone know of a device I can use to block specific RF channels before hitting a combiner?

I have two antennas pointing in two different directions and there are two RF channels that overlap which are 21 and 23. I am guessing that this is why I am not getting either of them because they are killing one another. I assume if I filter one out then the other will come through?

Or, even if they both are coming in would the Tablo still pick up the merged signal but it is just that you can’t watch it?

2

http://www.radio-electronics.com/info/rf-technology-design/rf-filters/rf-filter-basics-tutorial.php

Check out the Chebyshev filter.

3

Not sure what to make of the link. Do I order something from them, and if so where? The link seems to just be an explanation of filtering.

4

I was being a bit of a smart-ass with the link.

I don’t know of any product that filters specific channels, and if you read the story from the link you might understand why. You could theoretically put a high-pass chebyshev on one antenna and a low-pass on the other, and therefore not get mixing issues from multi-path when you combine them.

The most likely outcome is that you would kill all of your signal, and end up with next to nothing from either antenna.

5

I remember seeing once a coupler that filtered out channel 23 but I can’t find the link anymore.

I think it can be done, I did find something else interesting by accident.

6

There are notch filters available, however I believe they tend to remove a block of channels, and one of those blocks seems to be channels 19-23 (including both the channel you’re trying to remove and the one you wish to keep, alternately, from each feed) so that’s not likely to help:

Using this on either feed would likely kill both channels 21 and 23. I don’t know if you can find other off the shelf notch filters to block the individual channels you’re trying to remove.

7

Tin Lee (Toronto) supplies custom made notch filters for specific frequencies. Company well known in the industry. Prices not available from website - have to be negotiated as per customization. Expensive (perhaps $200 or more)!

Have ordered amplifiers and selective combiners from them in the past. Excellent service and they stand by their products. They will work to rectify a problem but there is a restocking fee for refunding returned items.

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8

This looks to be perfect and exactly what I am looking for. I looked over the RF channels and there is only one channel it will block that I was trying to keep but honestly don’t care to much about that one. It was on RF22 and I looked over my list and saw no channels on 19 or 20.

Found the notch filter on Amazon for $23

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