Group K Amp?

deaglan169

is there such a thing as a masthead group K amp

The Cush

deaglan169 wrote: »

is there such a thing as a masthead group K amp

Haven't come across a group specific amp, that's not to say they don't exist.

Why do you want a specific Group K amp?

deaglan169

you can get group specific amps, its for a friend i need to amp 21-48, but a group b will prob have to do, its to eliminate ch55 which is too strong, friend currently has a wideband amp on (always a bad idea)

Peter Rhea

You could use the low leg of a 50/52 diplexer as a filter on the wideband amp.

Triax & Fringe (others too no doubt) still make grouped amps but they seem to be A, B & C/D only. Same with group filters.

deaglan169

tried that but its still getting overload it improved a small bit, this person lives about 1 mile south of the monaghan transmitter on an elevated site, with a wideband antenna pointing towards divis ch55 is full signal and also 47 longford on the back of the antenna is full strength, even the analogue is grand from longford off back of antenna going to be hard to use amplification for divis yet null out the local tx

Peter Rhea

No point trying to make an amp work under those conditions.

Maybe try again next year when Divis is full power & all existing muxes back in group A.

deaglan169

i think so i was going to try a group k amp, i know now these dont exist so might try a group b and variable antenuator but i fear that when the dso goes fully live and when monaghan ups its power wont i still have this problem

Peter Rhea

I suspect Monaghan is already at full power, certainly the Saorview coverage map doesn't seem to have any red areas attributed to this tx.

Is the Monaghan mast directly in the Divis signal path? Maybe following switchover, a group A aerial will attenuate the Monaghan signal enough while still allowing good Divis reception or Brougher might be an option at that point.

In the meantime there's always satellite of course . . .

deaglan169

yeah was talking to friend who isntalls tv antennas and he recommended a group a antenna and amp, the monaghan tx is just slightly off the line of divis, never thought about brougher think he tried for it before and analogue was very poor from it, unfortunately he wants freeview for mainly quest so freesat aint an option, monaghan must be quite low power as ive tried for it in parts of armagh and its very hit and miss, would monaghan not be considered a border tx and be subject to offcom/comreg rules until dso and so on reduced power

Peter Rhea

No need to limit the power of the tx if it's not interfering with anything. The Lisbellaw relay is the nearest co-channel NI tx, but it seems to be well screened by the Slieve Beagh hills. Camlough will be co-channel after switchover.

Also no point in using Monaghan to cover areas in Armagh that will later be covered by Clermont, along with a fair bit of north Monaghan if the coverage map is to be believed.

Booms

Would a single channel filter for ch55 (and maybe another for ch47) inserted between the aerial and the amp be of any benefit? (I don't know, but I'm sure someone who's familiar with these will reply)

The reason I ask is that about ten years ago I tried this using a variable channel filter to remove my local ch33, and even using two in series there was still a very strong signal passing through. I'm about two miles or so from Three Rock. Wasn't using an amplifier, and it was analogue signals only at that time.

Peter Rhea

Booms wrote: »

. . . even using two in series there was still a very strong signal passing through.

I'm sure decent professional quality notch filters would offer better performance.

See page 7 here

deaglan169

just a quick update got this sorted today, swopped out wideband amp for a group A supreme, now have all the freeview bar 1 mux the one carrying dave but it cant be got in this area so no biggy, also turned the antenna from longford horz to clermont vert, rte picture has improved and the antenna being vertical now has a 20db drop on the monaghan signal, friend is now happy out come the offical switchover he should have all:D