DTT Tests @ Holywell Hill

sesswhat

Receiving strong signal on CH30 in Ballybofey.

byte

Didn't think you'd get a good signal from Holywell in Ballybofey. I figurd that's why Ballybofey got its own transposer.

Anyway, good to see another Tx with DTT.

Sponge Bob

thats the last of the Main Transmitters innit ??

byrnefm

Just did a scan now upon reading this thread this evening - full signal strength on channel 30 in the Glencar area of Letterkenny with just leaving my house aerial as it is

I'm just using a Wharfedale Freeview box to check the signal strength and the station names being transmitted. No channels are broadcasting as of yet, there's just a carrier signal.

sesswhat

byte wrote: »

Didn't think you'd get a good signal from Holywell in Ballybofey. I figurd that's why Ballybofey got its own transposer.

Anyway, good to see another Tx with DTT.

Most of Ballybofey would not get Holywell but I'm a couple of miles south and higher up. I also have a wideband aerial with masthead amp pointed at Limavady for Freeview, which also picks up Holywell Hill.

I haven't invested in any mpeg4 equipment as yet. The Freeview TV and boxes are showing a 'Very Good' quality and about 80% strength signal on CH30 but won't tune in anything. I don't know if this is to do with Service Types etc. or even if there is mux there yet.

Maybe someone with mpeg4 enabled equipment will be able to test it properly.

As Sponge Bob says, the last of the initial phase to go live so things are still pushing ahead.

egal

I thought channel 30 was supposed to carry the public service broadcasters?

sesswhat

egal wrote: »

I thought channel 30 was supposed to carry the public service broadcasters?

My mistake. It is 30:o Edited now to avoid confusion.

johndoc

Apologies in advance of the following dumb question but with the guys above mentioning doing a test with equipment other than MPEG4....
I've tried a UK freeview box and can pick up radio, RTE1, 2FM, Lyric....
(signal is around 70%)

Ingoring the signal strength/quality for now.. does this mean I'm good to go, I'm only getting radio while using the UK equipment and that I'll have picture once I get a proper MPEG4 decoder???

byrnefm

sesswhat wrote: »

Receiving strong signal on CH30 in Ballybofey.

The signal seems to be gone again... nothing at all now on any channel. It was there yesterday.

lawhec

byrnefm wrote: »

The signal seems to be gone again... nothing at all now on any channel. It was there yesterday.

Playing the devils advocate, I wonder if it was interfering much with Mux 1 (BBC, which is also on E30) from Brougher Mountain in parts of its service area?

When I expected Holywell Hill to start testing I expected them to use E35 as its a clear channel.

byrnefm

lawhec wrote: »

Playing the devils advocate, I wonder if it was interfering much with Mux 1 (BBC, which is also on E30) from Brougher Mountain in parts of its service area?

When I expected Holywell Hill to start testing I expected them to use E35 as its a clear channel.

Perhaps but I think channel 30 is clear in Letterkenny - we get all our NI channels from Strabane, as far as I know. I can't remember the BBC channel # offhand but it's in the high 30s or low 40s.

egal

lawhec wrote: »

Playing the devils advocate, I wonder if it was interfering much with Mux 1 (BBC, which is also on E30) from Brougher Mountain in parts of its service area?

When I expected Holywell Hill to start testing I expected them to use E35 as its a clear channel.

I was looking out for interference here on western side of Omagh - none so far. Maybe signal reduced into North.

My guess switched off for weekend in case of interference problems.

lawhec

byrnefm wrote: »

Perhaps but I think channel 30 is clear in Letterkenny - we get all our NI channels from Strabane, as far as I know. I can't remember the BBC channel # offhand but it's in the high 30s or low 40s.

I think I got picked up wrong on this, I was thinking more wherever the Holywell Hill tests on E30 was interfering in the Brougher Mountain service area rather than the other way around. All DTT muxs from Brougher are just 500W apeice.

Certainly parts of Omagh, Drumquin and places north of them which are not shielded from Holywell Hill/Sherrif's Mountain which rely on Brougher Mountain for Freeview/UK DTT reception could be susceptible.

BBC1 analogue from the Strabane relay is broadcast on E39.

Mike 1972

When I expected Holywell Hill to start testing I expected them to use E35 as its a clear channel.

If they do I wonder how many perfectly good videos get chucked into landfill as a result because their owners dont know about retuning................

sesswhat

Test signal is back this morning, but on CH35.

lawhec

Mike 1972 wrote: »

If they do I wonder how many perfectly good videos get chucked into landfill as a result because their owners dont know about retuning................

Considering that most VCR's are pretuned with a modulator to E36, A DVB-T signal on E35 shouldn't cause problems unless the signal being received is particularly strong and even if it does interfere, the worst it will do is make the screen a bit snowy. Shouldn't be a major problem. The Channel 5 retuning process back in the 90's was deliberatly over cautious at first and then they decided to only respond to fixing VCRs etc. if the Channel 5 signal was casuing interference.

byrnefm

sesswhat wrote: »

Test signal is back this morning, but on CH35.

Yip - I 'see' it too. Note that the signal strength is weaker on this channel: I get approx 85% 'signal strength' as opposed to 100% when it was on channel 30 a few days ago.

byrnefm

No signal on ch 30 or 35 for the past two weeks now...

egal

Anything on channels 25 or 32?

byrnefm

egal wrote: »

Anything on channels 25 or 32?

I just tried there now. No Irish DTT signals at all from here in Letterkenny at the moment.

However, I have found (on analog) that I can get a weak Channel 5 on UHF ch 37! Last night it was watchable, today it's not very much so. First time I've ever seen it on analog TV The Derry transmission of Channel 5 has major interference with BBC 1 on UHF ch 31.

lawhec

byrnefm wrote: »

I just tried there now. No Irish DTT signals at all from here in Letterkenny at the moment.

However, I have found (on analog) that I can get a weak Channel 5 on UHF ch 37! Last night it was watchable, today it's not very much so. First time I've ever seen it on analog TV The Derry transmission of Channel 5 has major interference with BBC 1 on UHF ch 31.

Sounds like the interference is coming from Belfast, as BBC1 from Divis is on E31 from there and Channel 5 from Black Mountain is on E37.

byrnefm

Small update:

There are two DTT blank carriers coming from Holywell Hill now:
UHF Channel 25, coming in as "Medium"
UHF Channel 35, coming in as "Poor"

I pick up Holywell Hill very well on analog from where I am so if a signal is coming in as Poor, RTÉ NL must have the signal on very low power indeed.

mrdtv

byrnefm wrote: »

Small update:

There are two DTT blank carriers coming from Holywell Hill now:
UHF Channel 25, coming in as "Medium"
UHF Channel 35, coming in as "Poor"

I pick up Holywell Hill very well on analog from where I am so if a signal is coming in as Poor, RTÉ NL must have the signal on very low power indeed.

Possibly to reduce operarating costs?

johnbk

I have DTT working in Kilkenny for the last 6 months on a Technomate 6900 HD combo. I will bring it with me the next time Im home (Finn valley). I have the ariel at home pointed to holywell to get TV3 (Cant get it from Ballybofey), however the picture isnt great. I have noticed in Kilkenny any sniff of a signal and the DTT seems to work.

byrnefm

DTT is now broadcasting on UHF channel 30 from Holywell Hill Only RTÉ1 and 2 have pictures, the others are the coloured bars.

At last!

sesswhat

I just tuned them in on a Freeview PVR. Nine channels numbered from 800 to 808 on the EPG. The extra channel is called RTENL test.

I might try them out with my neighbours new mpeg4 set if I get a chance.

sesswhat

Just noticed DTT reception has returned today.

Domscard

Yes, great to see it back - all except TG4.

egal

So, what channels are active now?

byrnefm

Currently there's RTÉ 1, RTÉ 2 (both an upscaled HD and regular ('Temp') SD, TV3, TG4, RTÉ News Now and 3e. There are also several radio stations.

egal

Sorry, I meant what UHF channels are active? Channel 30? Anything else?

Sam the Aerialman

Anyone one know why there are two broadband UHF panel antennas plonked onto the side of the Holywell Hill Tx building or what they are possibly radiating?

dmm1000

in the past week i have used a Swires "Terry" meter to test for Holywell Hill and i am gettiing the meter to flicker between F (Fail) and M (Marginal)
there are 3 settings on this meter - Fail / Marginal / and Pass

I'm at the foot of Altnapaste mountain (side next to glenties) and getting a reading of 41 db max on the meter on channel 30 and that is the max i can achieve - i'm using an unamplified grid type wideband aerial - but no success in getting channels on a scan using a sagem picnic box \ and laptop with usb tuner

I have used the same meter and same equipment on my uncles property which is a few miles up the road and lot higher up and with the same aerial and sagem picnic box / laptop and usb tuner and am getting about the same level 40/41 db - but i am getting the saorview channels on a scan - albeit affected by windmill interference

the question really is probably for any installers familiar with the Swires "Terry" meter
In 2 different locations i get the same signal reading about 40/41 db but get channels in one location and not the other am i right in saying that the meter is giving a strength reading in both cases and not necessarily a quality reading as the level is 40/41 db in both cases ?
just wondering is it worth investing in something like a Televes DAT 75 aerial could it possibly give me the extra boost i need or would i need to use a meter that would give me a signal quality as opposed to signal strength reading as i suspect the Swires is giving me a "strength" reading - maybe anyone familiar with the Swires "Terry" meter could answer that ?

egal

Sorry, I am not in a position to answer your query. But, the windmill interference at your uncle's site, what form does it take? Does it make the digital signal unwatchable. I cannot get digital RTE at my location here in Omagh but my analogue signal (from Clermont) is sometimes subject to windmill interference, but still watchable.

Sam the Aerialman

dmm1000 wrote: »

in the past week i have used a Swires "Terry" meter to test for Holywell Hill and i am gettiing the meter to flicker between F (Fail) and M (Marginal)
there are 3 settings on this meter - Fail / Marginal / and Pass

I'm at the foot of Altnapaste mountain (side next to glenties) and getting a reading of 41 db max on the meter on channel 30 and that is the max i can achieve - i'm using an unamplified grid type wideband aerial - but no success in getting channels on a scan using a sagem picnic box \ and laptop with usb tuner

I have used the same meter and same equipment on my uncles property which is a few miles up the road and lot higher up and with the same aerial and sagem picnic box / laptop and usb tuner and am getting about the same level 40/41 db - but i am getting the saorview channels on a scan - albeit affected by windmill interference

the question really is probably for any installers familiar with the Swires "Terry" meter
In 2 different locations i get the same signal reading about 40/41 db but get channels in one location and not the other am i right in saying that the meter is giving a strength reading in both cases and not necessarily a quality reading as the level is 40/41 db in both cases ?
just wondering is it worth investing in something like a Televes DAT 75 aerial could it possibly give me the extra boost i need or would i need to use a meter that would give me a signal quality as opposed to signal strength reading as i suspect the Swires is giving me a "strength" reading - maybe anyone familiar with the Swires "Terry" meter could answer that ?

Down the years i've had a a couple of the Terry 'T Shaped' meters and got rid of them for several reasons. There are several problems, particular versions don't have the 12v line out if for example when you're using a masthead the interpretation of the signal is completely off.
Another issue if you're not completely certain with the meter on a daily basis of use the interpretation of the result can be altered by the installer through different parameters. The noise floor is measured by each returned result. It then uses it's own memory to determine the last scanned frequency then the bar graph appears. You need to make sure you are searching everytime using the scan button and checking the returned result. The meter may be just returning a previous measured result stored in it's memory. You also need to check an annoying feature with the DTT settings on this particular meter were on an analogue channel it will measure anything, with a DTT channel if there is no signal it simply skips over it and forces a complete re-scan again and again to the point were you wish to smash it!

dmm1000

thanks Sam
I had my suspicions about the meter i suppose for around the £300 quid mark you get what you pay for and yes i do find the interface clunky as well

@Egal - to answer your question in regards to the windmill issues - the problem seems to manifest itself as pixellation and picture breakup and momentary freezes as the blade of the windmill cuts across the signal path
the Uncle is currently getting analogue RTE from Letterkenny but is just about in range of Holywell hill (but useless due to windmill interfereence)

Sam the Aerialman

dmm1000 wrote: »

Just wondering is it worth investing in something like a Televes DAT 75 aerial could it possibly give me the extra boost i need or would i need to use a meter that would give me a signal quality as opposed to signal strength reading as i suspect the Swires is giving me a "strength" reading - maybe anyone familiar with the Swires "Terry" meter could answer that?

Forget about a Televes DAT75 unless you want plastic flashings falling into your garden. Get a hold of a Triax 18 Supergain or if you feel you need the gain a Unix52 would be a far far better aerial. The Televes aerial carries an MRD that requires another separate power supply unit and in my experience an utter waste of time. The wind loading of such a large and un-necessary aerial will cause you future grief if adequate bracketed isn't used.

dmm1000 wrote: »

I had my suspicions about the meter i suppose for around the £300 quid mark you get what you pay for and yes i do find the interface clunky as well

Well no not at all. I have a Horizon HDTM plus meter bought for less than 3 hundred quid and is one of the best i've ever had. You can set up all your individual channel groups per transmitter, quick run through and all results are listed with a full BER function and pass/ fail rate. You can set it up, leave it to tweak with the aerial and it will give a full channel reading instantly. I have a Promax meter that barely gets out of the back of van it's that good.

watty

Or Blake SR18, or a pair of Blake SR18 with identical length feed to a splitter as combiner. Very robust.

Another idea
This will not work for analogue, but may solve Windmill Interference on Digital. Put two indentical aerials as far apart as possible. Measure out two identical lenghts of cable to join them to a splitter as combiner. On Analogue adjust for most ghosting!. On DTT the timing of the loss of signal if the aerials are far enough apart may be different on each aerial. DTT can use multipath (ghosting) to improve signal. This is why Kippure and Three Rock are SFN as in many parts north of Dublin there is signal from both.