I have a quick question which hopefully someone can answer.

Lets assume I have a triplexer in the loft to combine TV, FM and DAB signals into a single cable that is wired throughout the house.

Since there doesnt appear to be a triplexer wall plate that matches the aboce configuration how do the diplexer wall plates work where you have TV and FM/DAB?

How does it know when you have connected a DAB or FM radio to it or is it more stupid and simply diplexes the UHF signals out? In which case do I then have to further split into FM and/or DAB accordingly?

Many thanks

Haydn

[AMc]

The 3 way diplexer in your loft should be carefully integrating the various frequencies and discarding signal in the other bands from each aerial (with notch filters IIRC).
The 2 way diplexing socket will simply be splitting the UHF and VHF (?) signals out so DAB and FM will be taken as roughly the same range and TV as seperate.
In my experience tri or diplexing at the masthead is a good idea as it cuts down on cable so avoids signal loss and interference. Diplexing back out again doesn't seem to be that important - my TV, Freeview, FM and DAB tuners all seemed perfectly happy working from a simply split output and no diplexing.
If anything analogue TV and FM are most likely to be bothered by interference - freeview and DAB are digital so as long as there is a tollerable level of signal the effect of other channels in the signal is minimal.
Adding a TV/FM and then an FM/DAB diplexer will introduce more signal loss and won't add anything in my estimation.
Use a decent quality wall plate and a 3 way splitter with F-connectors and you'll be fine.

many thanks for the quick reply.

Thats pretty much what I thought - just wanted to be sure before I started to hunt down bits I dont really need.