Anyone use a Diplexer as a filter


and did it work well. Was thinking of finding one and trying it.


I have used one, but since I use a satellite amp that cuts off below 950 Mhz, it’s hard to say if the diplexer does any good at all. I sometimes take it off and then put it back on and honestly don’t see any difference. If you weren’t using an amp in the 950-2150 Mhz range, the diplexer might make a noticeable difference.


I kept stats as I made changes to my setup. I kept plane and message counts for a week after each change.

Adding in the diplexer increased my daily planes and messages by 9%. This was without any amplifier.

Also, you might hear that you need to add a terminator to the unused port on the diplexer. I tried this and had a 0% (i.e. no change) increase.


I use a 950 - 2150 amplifier and I put a diplexer in the RF chain. I found the plane count and distance were better. I didn’t do it scientifically so can’t quote stats :unamused:


I use a diplexer and it makes a big difference. I have a a lot of strong mobile phone transmitters nearby. Here is what happens when I take it out of the circuit:


Using a filter for an 950-2150MHz amp can be a good idea, if you feed if with frequencies out of that range, which you are basically doing by connecting it to an antenna.

950-2150MHz must not mean that the other frequencies are filtered out. It just can be the operational range of the amp. If you are feeding it with other signals, it is designed to use, especially strong ones (radio, cell phone, …), frequency conversion products can occur, which makes things even worse.

So, although the label says 950-2150MHz, it can mean that a filter should be used for your purpose, which is actually not the main purpose (using it in a satellite TV, where only the specified frequency range is used), so that your system is working in an intended and proper way.

Someone said in another thread, he saved the money for the filter, because the “amp is 950-2150MHz”. I think this thought is a bit too simple…




Though it made no noticeable difference for me - In your position, I’d try it - it’s cheap and might work


I have had positive results as well.



The operational frecuency of the amp is 950-2150MHz (that’s the frecuency it will amplify)…
It doesnt say what it does with the other frecuencies. (pass-thru)

the filter on the other hand… eliminates (or highly attenuate) the frecuencies not in it’s operation frecuencies…

If you have high noise in the 800Mhz range (cell towers)… The amp will not enhance it… but it won’t eliminate it niether… (the filter will)…


Was talking about a Diplexer not an Amp. Common diplexer is a CATV/SAT … CATV is 5-860 and sat is 950-2500

Might try to find one for giggles. I have a cell tower about 1/2 mile away and would like to cut the noise down some.


Evening all,
Was thinking of adding a duplexer like this as part of my amp upgrade recently.

Actually have a duplexer, but how do I actually use it as a filter?


Connect the antenna cable to the ANT&SAT port… and the Dongle to the SAT port…
Look at this thread…