Diplexing problem

Inishowen

A new transmitter at Quigley's Point, Donegal is broadcasting RTE1 (Ch 46), RTE2 (Ch 52) and TG4 (Ch 68). How can I combine these channels with BBC1 (Ch 55), UTV (Ch 59), BBC2 (Ch 62) and CH4 (Ch 65), all from Limavady? I tried a splitter in reverse but there was a big loss from Limavady and the RTE's were poor. I live about 1 mile from the mast. Any suggestions?

Ulsterman 1690

I tried a splitter in reverse

What kind of splitter was it ? It it was one of those horrible cheap plastic "Y" things Im not suprised

Combining channels in the same group can be tricky. Even with a good splitter you might potentially have all manner of phasing and ghosting problems. You can get channelised filters but they can be expensive

rlogue

Crikey, it's hard to keep up with new transposers - there's nothing on Aertel about the site - where else can I find out about the mast?

watty

Inishowen wrote:

A new transmitter at Quigley's Point, Donegal is broadcasting RTE1 (Ch 46), RTE2 (Ch 52) and TG4 (Ch 68). How can I combine these channels with BBC1 (Ch 55), UTV (Ch 59), BBC2 (Ch 62) and CH4 (Ch 65), all from Limavady? I tried a splitter in reverse but there was a big loss from Limavady and the RTE's were poor. I live about 1 mile from the mast. Any suggestions?

Put 6dB inline attenuator in aeial connection from RTE aerial (or even 12dB). use a 6dB booster amp on BBC aerial feed into splitter.

rlogue

Where in Quigley's Point is the mast located?

lawhec

Looks like RTÉ have rooted out the frequencies from what's available - TV3 must now never be planning to broadcast from Moville (at least in analogue) while they're going for 52 and 68 to avoid adjacent channel interference with Limavady. It's crowded up there folks!

Ulsterman 1690

watty wrote:

Put 6dB inline attenuator in aeial connection from RTE aerial (or even 12dB). use a 6dB booster amp on BBC aerial feed into splitter.

Dont Johanson (sp?) do a masthead amp (booster) with dual inputs and variable gain/attenuation on each input. That might do the trick because you can adjust the level on each input until you get a decent picture on all channels?

byte

Johansson do that sort of stuff alright
http://www.johansson.be/htmen/preampcomb.php?ref=7422

Not sure how great it would work but better than a Y splitter I'd imagine.

The only other option is channel-shifters to move the freqs of one of the Transmitters to another UHF group, but I'd imagine this to be rather expensive.

Propellerhead

Ch 52 and 68? Are these interfering with the Limavady Freeview TXs on 53 (SDN mux) and 67 (BBC mux)?

I was in Quigley's Point last Monday and didn't notice a new RTÉ TX then..

lawhec

Propellerhead wrote:

Ch 52 and 68? Are these interfering with the Limavady Freeview TXs on 53 (SDN mux) and 67 (BBC mux)?

It shouln't really unless the new RTÉ TX being received is so strong that it overloads the DTT tuner.

Many UK broadcasting sites, including Divis and Brougher Mountain, have DTT multiplexes on adjacent channels to analogue broadcasts perfectly fine.

Inishowen

rlogue wrote:

Where in Quigley's Point is the mast located?

It's located at Meenavanaghan (behind the Riverside Bar). It picks up Moville and transmits into the valley on the road to Carndonagh. There were no signals of any sort here, unless with a dish.

Ulsterman 1690

Are there really still places like this ?
What did people do before Satellite ?
Could they get the UK terrestrials either or were they reduced to dancing at the crossroads :eek:


ADDS: And before anyone says "Yes but theres other things to do besides watching telly" I suspect they dont have broadband either

watty

When I was a teenager in very late teens we visited Achill. I think the only thing receivable was BBC R4 LW.

Maybe they listened to "The Archers".

lawhec

There's a spot in the Sperrins on the Tyrone side a few miles north of the village of Greencastle where the best picture you can get from Brougher Mountain or Divis which is very weather dependent, on good days reasonably clear and unwatchable on bad days. Oddly enough RTÉ from Clermont Carn comes in very clear, but N.Ireland TV and FM radio is unreliable. The local pub has a hi-gain aerial on a 20 metre pole on its roof aimed at Brougher Mtn. Most people around there these days have Freesat, but I suppose the problem regarding Quigley's Point/Carndonagh is that RTÉ can't be viewed for free or a one-off cost via satellite.

Watty, BBC R4 didn't appear on LW until late 78 and I'm pretty sure the Achill TV relay was opened by this time so unless it was in a shadow I'm sure TV and even MW from RTÉ 1 was possible.

Ulsterman 1690

Northern Correspondent wrote:

Watty, BBC R4 didn't appear on LW until late 78 and I'm pretty sure the Achill TV relay was opened by this time so unless it was in a shadow I'm sure TV .

Maybe Watty meant Radio Two on LW ?

and even MW from RTÉ 1 was possible

I believe in parts of SW Kerry that 567 is pretty weak and 612 (when it was on) was inaudible but Ive never been there myself to confirm or refute this !

Inishowen

Propellerhead wrote:

Ch 52 and 68? Are these interfering with the Limavady Freeview TXs on 53 (SDN mux) and 67 (BBC mux)?

I have a Thomson DHD4000 and a Fusion FVRT200 and when TG4 on Ch 68 started I lost the BBC's on my Fusion, the Thomson was fine. When the aerial was moved outside from the attic it was ok.

watty

What ever was on 200 or 198. Maybe the hotels and pubs couldn't afford TV sets?

I think the MW RTE was very weak on car radio, not worth straining to listen to.

Who told you it was before 1978? It was infact perhaps between 1972 and 1976 inclusive. Don't remember exactly. Yes there was TV when I was there in 1979. But I was't there to watch TV or Radio then. I wasn't a teenager either. They still didn't have real telephones though.

L1011

watty wrote:

What ever was on 200 or 198. Maybe the hotels and pubs couldn't afford TV sets?

As goes TV on the islands, up in Donegal they got BBC1 405-line the day the power got turned on (1956? Got UTV when it started too). The height on Arranmore meant that the mountains weren't an issue for the most part. RTE was difficult to get until the Arranmore relay opened in the early-1990's, so it was UK TV, Highland radio and 567Khz until then.

theres so little to do that the hotels and pubs definately would get TV sets, the trade would offset it hugely.

jonnygee

I remember it well, there was no bbc 1, only bbc, it was our only channel, does anyone remember Mr.pastry. Our aerial was a toasting fork hanging on a nail hammered into the wall (truthfully). In the morning the fork came down to toast the bread and then was hung back up on the nail for our evenings viewing.