TV/FM Diplexer

[tompoole84]

Can some one help.

We have good strong Digital TV signal to our Humax HD Youview Box and HD Freeview Panasonic TV

Recently I upgraded my home amplifier which has a built in DAB/FM Radio, I purchased the following Diplexer http://www.maplin.co.uk/p/flush-mounting-tvfm-diplexer-yn54j After installing this I could not get any HD channels and the standard TV Channels where OK but poor signal. So I removed it and put the single fly lead back on and now is fine.

Am i doing something wrong I just changed the single tv socket on the wall to a diplexer yet it made everything worse

 

[Lucid]

The diplexer is just a frequency filter. It splits off the FM frequency range from the TV frequency range and presents each at the appropriate socket.

If you got no signal for TV after fitting the diplexer then it could be that it was fitted wrong (most common cause is shield braid wire touching the centre core of the cable), or the little bit of signal loss caused by the filtering process was just enough to tip the reception over the edge to where the TV won't work. This is called The Digital Cliff. Or you have an aerial on the roof with a masthead amplifier. The diplexer plate stops the power getting through for the masthead amp.

There's something else you should know about aerial systems and diplexers. If the only thing on your roof is a TV aerial then a diplexer plate won't give you an FM signal for the tuner.

What you need is an FM aerial on the roof and lined up on the mains transmitter for the station(s) you want to receive. You can either bring a cable downlead directly from the roof in to the room where the FM tuner is, or you can add that FM signal to the TV aerial signal so that both travel down the same cable. This is called multiplexing. The bit that brings the two signals together is sometimes referred to as a combiner or as a diplexer. Look at the V25-100 UHF + VHF/FM diplexer on this page. This is fitted on the aerial mast. Two cables in (TV + FM) and one out for the combined (multiplexed) signal.

Once the aerial cable carries two signals then the type of diplexer plate you have will split out the signals back to TV and FM.

 

[winston1]

Probably a cheap nasty diplexer. It certainly looks it.
Does the FM side also pass DAB? It does not say so.
You will need an FM and a DAB aerial and a triplexer/combiner to combine all three and a splitter at the bottom. If your DAB/FM radio has only one aerial socket you will need a diplexer that gives TV on one output and DAB/FM on the other. If is has two separate aerial sockets you will need a triplexer.

 

[Sam Gangee]

I purchased the following Diplexer

Have you a photo of the rear? With only 10mm depth, it can't be screened can it?