Three Rock - Poor TG4 Analogue Reception - Impact on DTT Reception?

MartyM

Hi Guys

Just wondering if anyone else on the Three Rock transmitter has experienced poor TG4 lately? OR anyone know why this has happened?

Not sure how long it has been poor because I dont watch analogue but I'm now considering purchasing a Sony TV for Saorview & Freesat and want to ensure I will receive the Irish DTT.

RTE1 - CH29 - Very good reception
RTE2 - CH33 - Very good reception
TV3 - CH35 - Very good reception
TG4 - CH55 - Crap reception

I live in Kilternan, so pretty close to the transmitter. I think I am receiving interference from Clermont Carn. I can see ghost images of RTE2 on CH56 and TG4 on CH68 (had to move my Sky box of this channel to improve RF2 output).

Was also told by a TV guy that they have been reducing the gain on the transmitter with the intro of DTT and thats the reason TG4 has degraded??

Basically, could one poor analogue channel indicate that I could potentially have DTT problems OR are the 3 good channels an indicator that DTT will be good?

Thanks!

watty

If TV3 or TG4 is good, then with appropriate Aerial DTT should be good.

All the current DTT channels are only one RF channel, a 2nd RF channel will be added if any additional channels start (Oireachtas, Film, another channel goes HD, or Test replaced by RTEjr/RTE+ and they want to keep a test channel).

The Cush

watty wrote: »

All the current DTT channels are only one RF channel, a 2nd RF channel will be added if any additional channels start (Oireachtas, Film, another channel goes HD, or Test replaced by RTEjr/RTE+ and they want to keep a test channel).

RTEjr/RTE+ will be launching on Mux 1 sometime after the Temporary RTÉ 2 channel ceases in April. No content yet for Mux 2.

MartyM

watty wrote: »

If TV3 or TG4 is good, then with appropriate Aerial DTT should be good.

Thanks Watty! Why just TV3 or TG4? I assume its because nationwide these are the only 2 channels that exclusively use UHF?

I see the same comment here:
http://www.techtir.ie/blog/Thomas/free-tv-for-dummies

"I learned that if you have an aerial that picks up TV3 and TG4, then you could use this aerial to pick up digital terrestrial TV (DTT)"

With the subtle differences highlighted in bold!


I still have the same concerns however. Three Rock only uses UHF for the 4 analogue channels, so the aerial should be fine.
Its the poor reception of TG4 that is worrying me and the potential knock-on affect for DTT.

I've also read somewhere that DTT on Three Rock is CH56, which is directly adjacent to TG4 on CH55. Bad frequency planning or not a problem? (definitely not a problem after 2012, but until then?)

Whats the cheapest piece of equipment I could purchase to test DTT before forking out €600 on a TV?

STB

MartyM

The reason for your poor TG4 reception sounds a little obvious to me.

Are you using a group A UHF yagi ? Sounds likely. Hence TG4 is out of band. It would seem to fit that description according to your frequency off analogue.

DTT is not as picky. Any sort of analogue recption should theoretically mean DTT will be fine (once its not a fill in area). You will have no problem in Kiltiernan picking it up, sure you could use a coathanger (see Sam Russell's posts for schematics )

Test DTT. Get a HD Combo Box - it does satellite and DTT in one channel list - you can get them for as low as €130+pp. Thats my suggestion.

lucernarian

In Kiltiernan a coathanger would work well to receive DTT. Clermont Carn has different channels to what Three Rock use and won't be an issue.

I've had signal levels low enough on TG4 that the TV could only manage black and white reception but I could still receive the mux from Three Rock.

MartyM

Thanks STB / To_be_confirmed

The reception on TG4 used to be much better. Never great on the second TV via RF2 from Sky box but good on the main TV, where the TV and SAT signals come in on the same cable and split using a diplexer.

I accept the coathanger arguement for my area but just for a better understanding, bare with me!

Group A = Channels 21-37

If the DTT for Three Rock is on one of these channels: 54, 58, 61, 64

http://www.techtir.ie/tv-radio/Irish-DTT-Sites

Or CH56 as I've read somewhere else on boards, it looks like I'm still out of band, no?

Aerial photo attached...communal aerial shared on a small apt block!

Thanks

STB

Presuming that is a Group A, then yes you would be out of band.

Would it make a difference to DTT reception ? I doubt it. You are too near the transmitter for the Group A to completely filter receptionin my opinion. Test it with a DTT box before you get the aerial changed - you shouldnt have to.

By the way your analogue wouldnt be helped by the nearness of Kippure frequency wise for Tg4, but you dont need to solve that now as analogue wont be on for much longer (infact you should forget analogue altogether - Digital is far superior to snowy analogue).

Get a basic DTT box with PVR via USB (non certified and without MHEG5 interactive software) that will display the channels for less than €50 - there are zillions of threads on such boxes. The Saorview boxes @ €99 are too dear.

Or get one that does satellite and dtt in one channel list as desrcibed above - see stickies and google the model - cheapest sites are in Poland.

MartyM

Cool, thanks for the info...will check them out!

Peter Rhea

Isn't the issue here a deterioration in TG4 signal quality over time?

Seems to indicate a problem somewhere which would more than likely affect the higher frequencies to a greater extent regardless of the aerial group.
Maybe cable or connections have been damaged somehow.

Also, being communal distribution, could someone else be 'polluting' the system?

STB

A combination of things Reaper.

Just as a matter of interest MartyM what type Tv do you have at the moment ? Does it have a digital tuner ? If it does you will know straight off what the signal level is like dvb-t wise (even if it doesnt display the picture). Some MPEG2 IDTVs will display the MPEG4 stations in a scan despite their limits. Manually Scan Ch54.

MartyM

Peter Rhea wrote: »

Isn't the issue here a deterioration in TG4 signal quality over time?

It certainly has degraded badly over the last few months. Previously it was pretty much on a par with the other 3 channels from what I rememember. Now, you couldnt watch it!

I had a guy out last week from the company in-charge of the shared system to connect a 3rd LNB/TV cable to the bedroom and he said they have been reducing the gain on analogue transmissions in prep for DTT??

Peter Rhea wrote: »

Seems to indicate a problem somewhere which would more than likely affect the higher frequencies to a greater extent regardless of the aerial group.
Maybe cable or connections have been damaged somehow.

Also, being communal distribution, could someone else be 'polluting' the system?

I hope not, I cant imagine them coming out to troubleshoot the problem! I can only check cables internal to our apt.

Our Sat LNB and Aerial share the same cable and I have noticed the last couple of nights that I have intermittent loss of signal on Sky1 HD, Living HD and Sky Atlantic HD. I thought it was my new Sky+HD box but could the higher freq problem you mentioned be a factor here too?

I also noticed only LNB input 1 lost the signal, so not sure why LNB 2 didnt just take over....anyway, thats a sat discussion!

MartyM

STB wrote: »

Just as a matter of interest MartyM what type Tv do you have at the moment ? Does it have a digital tuner ? If it does you will know straight off what the signal level is like dvb-t wise (even if it doesnt display the picture). Some MPEG2 IDTVs will display the MPEG4 stations in a scan despite their limits. Manually Scan Ch54.

Its a Panasonic TH-42PY70EY, so just a HD monitor from 2012!

STB

A yes the PZ is the dvb-t tuner range. They will have to turn down the amplification for dtt in Kiltiernan - other wise you will get overload.

Just get a cheap box from France - the TNT HD variety. They have more functionality - ie PVR via USB, MKV/Divx via USB media files.

Seek out the Akira €49 + pp.

MartyM

STB wrote: »

A yes the PZ is the dvb-t tuner range. They will have to turn down the amplification for dtt in Kiltiernan - other wise you will get overload.

Just get a cheap box from France - the TNT HD variety. They have more functionality - ie PVR via USB, MKV/Divx via USB media files.

Seek out the Akira €49 + pp.

Yeah, not sure why I opted for the PY over the PZ. I thought I did a lot of research before purchasing! and it was getting great reviews on the "HE Video Displays & Projectors" forum. Having said that, it is a great TV....just not future proofed!

Merci!

Peter Rhea

MartyM wrote: »

It certainly has degraded badly over the last few months. Previously it was pretty much on a par with the other 3 channels from what I rememember. Now, you couldnt watch it!

Does this problem affect other residents?

I had a guy out last week from the company in-charge of the shared system to connect a 3rd LNB/TV cable to the bedroom and he said they have been reducing the gain on analogue transmissions in prep for DTT??

I wonder how sophisticated the distribution system is & just what it can cope with. The best thing to do is find out if the problems are specific to your own apartment & work from there.

Antenna

STB wrote: »

By the way your analogue wouldnt be helped by the nearness of Kippure frequency wise for Tg4

Tg4 Kippure listed on Ch59
The OP has a problem on ch55

Since when has a weaker more distant analogue signal 4 UHF channels higher from the received analogue channel ever been considered a potential problem ??

MartyM

Peter Rhea wrote: »

Does this problem affect other residents?

I wonder how sophisticated the distribution system is & just what it can cope with. The best thing to do is find out if the problems are specific to your own apartment & work from there.

Yeah, will have to chat to other people. I could be the only one left on this system though. There are only 12 apts and we have:

* A Sky Communal Dish
* A Third Party Communal Dish & Aerial
* UPC

I stayed with the third party system because of the aerial...

MartyM

Antenna wrote: »

Tg4 Kippure listed on Ch59
The OP has a problem on ch55

Since when has a weaker more distant analogue signal 4 UHF channels higher from the received analogue channel ever been considered a potential problem ??

I see ghost images on the following:

CH52 - RTE1
CH56 - RTE2
CH66 - TV3
CH68 - TG4

Thats why I thought Clermont Carn.

And very weak on CH59 is another TG4, hard to make out though. This would be Kippure I guess.

Peter Rhea

The other transmitters aren't the problem.

Without knowing the makeup of the distribution system; the no. & quality of cables to each apt. & what they're trying to send down them or if it has to cope with high signal levels, being so close to Three Rock, it's hard to suggest a cause.

MartyM

Peter Rhea wrote: »

The other transmitters aren't the problem.

Without knowing the makeup of the distribution system; the no. & quality of cables to each apt. & what they're trying to send down them or if it has to cope with high signal levels, being so close to Three Rock, it's hard to suggest a cause.

Cables are marked 75 Ohm W102 CCS.

Apparently 3 TV/Sat cables to each apartment....12 apartments in total. Cables carry both sat and terrestrial signals.

Attached pictures may not add much but will include anyway. They're from the hallway common area in the apt block. Not sure which company owns what...

haymur

I am thinking of buying a Navman Mio Sat Nav either a V505 or V575 with digital tuner. Has anyone tried one in Dublin or the whole country for reception . It has freeview but I also read it works all over Europe on FTV.On another site. It says it has a EPG and I wonder if its possible to have all these tuner features in such a small product.

Peter Rhea

MartyM wrote: »

. . . Attached pictures may not add much but will include anyway. They're from the hallway common area in the apt block. Not sure which company owns what...

What a mess! Well straight away I can see that the top cable coming out of the large multiswitch looks a bit strained (where it's going to is another matter).
Cables shouldn't be left hanging on their connectors like that.
I'll assume it's the original system that you're connected to & the 3 cascaded switches below are for Sky. It's probably been disturbed when cables have been switched to the Sky system.

MartyM

Peter Rhea wrote: »

What a mess! Well straight away I can see that the top cable coming out of the large multiswitch looks a bit strained (where it's going to is another matter).
Cables shouldn't be left hanging on their connectors like that.
I'll assume it's the original system that you're connected to & the 3 cascaded switches below are for Sky. It's probably been disturbed when cables have been switced to the Sky system.

Yeah, I was thinking that myself. The top multiswitch has 5 cables connected, which means 2 apartments....3 of the 5 are to my apartment.

I was also thinking the problem is not between the multiswitch and my apt because I have a diplexer on 2 of my 3 cables to provide terrestrial in the sitting room and in the bedroom.

Both rooms show a poor TG4 and are from 2 different cables....

Peter Rhea

Is the multiswitch itself just hanging on its cables or has it some other support?

MartyM

Peter Rhea wrote: »

Is the multiswitch itself just hanging on its cables or has it some other support?

Well, not sure how much of a support it is, they're looped through a plastic ring and slightly supported by another cable...see attached pic.

Peter Rhea

You've probably already tried removing all satellite equipment from the equation (you mentioned changing RF2 channels already).

Apart from that, all I can think of is to get the installer back.

MartyM

Peter Rhea wrote: »

You've probably already tried removing all satellite equipment from the equation (you mentioned changing RF2 channels already).

Apart from that, all I can think of is to get the installer back.

Yeah, well the sitting room was always a direct aerial connection....as direct as it can be on a shared cable and using a diplexer.

The bedroom was previously only on RF2 and a magic eye. Now this is removed and I have a third LNB/Aerial connection directly to the bedroom.

Thanks for taking the time to look into the problem Peter!

lucernarian

Here's a tip: You can buy a really cheap DTT stick off ebay (for DVB-T) or else get a flatscreen TV which is likely to have a digital tuner. You can do a channel search on Ch. 54 and it will provide signal strength and quality too even if it can't show the video part of any channel. It's a convenient way to test if you can receive DTT or not. The USB stick has the added advantage of being able to show video if you configure it right and install the right software etc.

Of course, it's not a solution if you are bothered by not having good analogue TG4.

MartyM

To_be_confirmed wrote: »

Here's a tip: You can buy a really cheap DTT stick off ebay (for DVB-T) or else get a flatscreen TV which is likely to have a digital tuner. You can do a channel search on Ch. 54 and it will provide signal strength and quality too even if it can't show the video part of any channel. It's a convenient way to test if you can receive DTT or not. The USB stick has the added advantage of being able to show video if you configure it right and install the right software etc.

Of course, it's not a solution if you are bothered by not having good analogue TG4.

Had a rush of blood on Saturday and went out and bought the Sony KDL-32V5810......Fressat and Saorview coming through perfectly!

Pity the demand for these Freesat TVs hasn't been great in the UK, because if they ever decide to add PVR functionality....its the perfect solution! Pretty sweet as it is!

lucernarian

There you go! Let no one underestimate the sheer power of Three Rock post ASO. It should cover parts of Co.Down which Clermont Carn can't easily reach like Downpatrick and places east of there with no bother.

SRB

With the "lift" this morning Three Rock DTT is loud and clear this morning here in Portaferry Co Down, been a while since I've had a lockable signal. Been sitting steady at 100% quality for the last few hours. (Analogue from the same site is perfectly watchable too.)