Diplexer - Televes vs Alcad - Page 1
Forum section: electronics / projects

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 12:24:25 pm
content: Hello everyone,I am trying to decide between two diplexers and I was wondering if anybody in the forum hadany experience with either of the following:a)Televes 7452http://www.televes.com/en/catalogo/producto/combiner-matv-if-5862-9502050mhzdcb)Alcad ME214http://www.alcad.net/uploads/fichas/9020015ti.swfI have been using for many years products from Televes and they are of great quality but thisdiplexer from Alcad has better specs and lower price. Lower insertion loss, higher frequencyand higher IF rejection.Are these specs 'Chinese'?...Has anybody tried any of the above diplexers?Any comments on the quality of other Alcad products?Thank you!George.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 03:53:02 pm
content: HiIs this a one off buy or are you switching out a bunch of them? If you are doing a system switch out ( = buying a lot of them), I'd get one and leave it out in the rain for a few months to see how it does in the real world....Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 04:15:34 pm
content: I will buy just a pair of them and I will use them inside the house.I am trying to combine a terrestrial analog TV signal with the outputof a MoCA adapter that carries ethernet data and pass them througha single Coax cable. I am not sure if it will work.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 04:27:34 pm
content: HiFor indoor use, I'd bet that either of them will run for a long time. It has been a while since I put the MOCA stuff in the house here. I don't recall having to do diplexers in that case. I put blocking filters on to prevent upstream feed, but that was about it.Bob

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 13, 2016, 04:38:42 pm
content: Rather than spend a lot on MoCA stuff, you can try running Wifi over the coax line.http://wifiovercoax.mcleodnet.com/

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 05:02:15 pm
content: Quote from: NiHaoMike on February 13, 2016, 04:38:42 pmHiThat's a good point. In my case the MoCA stuff was "free". It came built into some boxes and there was nothing else I needed to buy. If I had to pay to put it in, I would try something else.Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 05:03:19 pm
content: @uncle_bob Do you mean preventing upstream feed to the terrestrial aerial ?@NiHaoMike I already have a Netgear MoCA adapter running for years without a problem.I just want to use a single coax to combine the MoCA signal with an analog TV signal.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 05:35:19 pm
content: Quote from: hgg on February 13, 2016, 05:03:19 pmHiI have a fairly strange system. I run both cable and over the air. The filters were first for blocking back feed to the cable. I then put them into the antenna system as well. I very much doubt they are needed for the antenna. In both cases, the function is mostly to keep the neighbors out of your system (and you out of theirs).Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 05:45:08 pm
content: I see. I've heard that if you don't mix the signals properly you might cause interference from yourTV aerial to police/fire etc communication. I am not sure if its possible.Do you have any link to see these blocking filters or similar?Thanks.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 06:20:21 pm
content: Quote from: hgg on February 13, 2016, 05:45:08 pmHiIt is technically possible to radiate a MoCA signal from your over the air antenna. With the particular antenna I have, that was not a big worry for me.Here's what I bought:http://www.amazon.com/Filter-MoCA-Cable-Coaxial-Networking/dp/B00DC8IEE6I can't say that I put a lot of thought into selecting this one. There may be better / cheaper / quicker solutions out there.Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 06:26:19 pm
content: Quote from: uncle_bob on February 13, 2016, 06:20:21 pmI see. This is for cable tv. I am using the moca adapter to pass only network data through coax and now I want to mix an analog tv signal as well.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 06:41:03 pm
content: Quote from: hgg on February 13, 2016, 06:26:19 pmHiI have no idea what the "cable only" thing is about. It blocks the MoCA and passes the frequencies that I get over the air TV on. There may be a big brother to this that has more attenuation. They also may be talking about it blocking satellite hookups.Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 06:49:51 pm
content: If I understand correctly, this is a low pass filter and I don't need to use it because I will beusing one diplexer in each end.

author: uncle_bob
author_rank: Unknown
timestamp: February 13, 2016, 07:06:04 pm
content: Quote from: hgg on February 13, 2016, 06:49:51 pmHiExactly correct. You already have low pass filters in the diplexers. In my case I did not need diplexers on the gear I had. The only requirement was for blocking filters at the "ends" of the system.Bob

author: hgg
author_rank: Frequent Contributor
timestamp: February 13, 2016, 07:09:05 pm
content: Great, thanks for your help!