diplexer use ?

syboit

Hi,

Would a diplexer work in the following situation? Want to see if you can get dvb-t down the same line as the chorus mmds connection.

1 cable going from attic down to tv. mmds aerial and uhf aerial going into attic, currently mmds connection is joined to the run going to the tv.

If you put both aerials into a diplexer , then another one down in the tv room where it comes in. 1 lead going to mmds box and the other going to freeview tuner in tv.

byte

Depends on what frequencies is used by the MMDS downconverter. Some I've seen are VHF, others use the top end of UHF

syboit

byte wrote: »

Depends on what frequencies is used by the MMDS downconverter. Some I've seen are VHF, others use the top end of UHF

ta, would have no idea how to figure that out. So if it was UHF i persume you cant combine 2 uhf aerials ?

maxg

UHF downconverter are only used at very old installations for analogue mmds.
The main problem for combining is the current for the mmds aerial.
It would be a good idea to move the psu for the aerial to the attic and combine behind.

watty

you can get splitters and diplexers with power feed on only one leg.

maxg

The builtin short circuit protection at some diplexer is not so good for mmds. A mmds downconverter need more power than a mast amp.
A splitter eat up too much signal strength.

byte

maxg wrote: »

UHF downconverter are only used at very old installations for analogue mmds.

True that, though it's all that's used in Donegal Town by Chorus/UPC. It's analogue of course. Using UHF channels 40 up to 68 or thereabouts (stupidly MTV is on C60, which can cause conflicts with TV3 from Truskmore using the same freq). Then diplexer to combine VHF for RTE 1 and 2. They use Teleste combiners.

watty

I've had a very old one (box behind dish) and a new one (converter in stalk holding dipole), they were both VHF/Hyperband between 200MHz to 460MHz approx (Can't remember exact frequency).

I've heard all right that there are some UHF ones in Limerick.