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All posts by PaulN

Below are all of PaulN's postings, with the most recent are at the bottom of the page.

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Clermont Carn Saorview transmitter
Sunday 19 August 2012 5:52PM
Larne

Can someone confirm that clermont carn is actively transmitting saorview 24/7 these days ?

I challenged myself to see if I can receive saorview in BT40. I bought a decent aerial and masthead amp and a filtered combiner to mix with freeview signals. I bought a triax official saorview decoder and no joy yet.

Quick summary of results so far:

Receiving four analog channels ok - rte1 is barely watchable. Tv3 and tg4 are grand while rte is a bit furry.

The decoder is seeing signal on channel 53 and 57 - but it never indicates any decent "quality" metric and never successfully finds channels in the mux at C53.

I am using decent PF100 cable everywhere, fresh f connectors etc. The aerial has 18dB gain while the amp is 27dB.

I have another tv that has mpeg4 DVB-T2 receiver although not official soarview - it has same behaviour.

Is it simply cos the launch power at clermont carn is so weak that the decoder is unable to extract any meaningful data from it - despite all the gain I have ?

The aerial was aimed live while viewing worst channel.

Some questions - is it worth trying the aerial with a lot more elevation above the roofline as I kept it quite low to reduce impact of wind loading as its quite a hefty aerial - labgear 450W.

The weird thing is that the triax decoder picks up the uk freeview signals just fine - and it reports similar signal strength on some of the uk muxes as it does the Irish ones.

It gets weirder as some uk muxes report much higher strength than other. Best example is C33 which reports 15% while C34 is 90%. My other decoders do not see such diffierence in strength while they all receive at same lovely quality.

Bit perplexed so keen for any expert advice. I may yet rent a specialised measurement set.

Paul

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Clermont Carn Saorview transmitter
Monday 20 August 2012 1:35AM

Thanks Peter... I am in Larne area... don't wish to give out exact postcode here obviously.

My Divis reception for analog & digital is fine. I do get some sessions of crappy performance on MUX1 (C29) and MUX2 (C33) - what are these 'lift conditions' you speak of ?

MUXs A thru D are much less affected for some odd reason.

Another Q I forgot to post - is there significant benefit with masthead amp installation as close to aerial as possible ?

Mine are approx 2-3m from aerials with a nice dry location in the attic where I can lash things up for testing and try different things. A decent 'loft box' distributes the aggregated UHF to a few TVs in the house.

Aggregation is done by a Triax 5052 filtered combiner - the dual aerial setup is pretty impossible without that.

I am reckoning to wait until after Oct 24th to see what improvements occur - then maybe I will experiment some more with taller masts etc.

Its annoying that NIMM isn't destined for Divis - that would have been too convenient I suppose.

If all else fails there is always Saorsat but that would feel like defeat really.

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Clermont Carn Saorview transmitter
Monday 20 August 2012 2:21AM

Just had a mad idea... could I have too MUCH gain on the SaorView setup - would that saturate the receiver and make it unable to decode anything ?

Data here is stating 160kW on Clermont while the Freeview channels on Divis are below 2.5kW and I have the same gain on each antenna - broadly speaking.

I am much further from Clermont.

I was also perplexed that RTE1 & RTE2 on C52 and C56 respectively are visibly poorer than TV3 and TG4 at C66 7 C68... I have just noticed the possibility that I could be getting interference from Whitehead transmitting on C52 and C56 in Vertical polarisation.

I dont aim directly towards the Whitehead station but I smell something here... Going to try an amp with variable gain and see what the saorview decoder gets on C53.

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Clermont Carn Saorview transmitter
Monday 20 August 2012 11:14AM

No cigar.... dropped the gain down and could see immediate effect on the analog signal strength but SV1 and SV2 look very weak according to strength indication on the Triax STB. Oddly it reports perfect signal quality so that metric is clearly useless.

Maybe SV1 doesn't launch with full power until Oct 24th - little point in me trying much more until then... maybe I can rent some snazzy measurement gear to get readings before and after DSO. Maybe add a different high gain aerial as well to so if that performs any better than the Labgear450W.

Maybe I am just too hopeful of my chances this far from the transmitter - especially with the potential for Whitehead complications.

Will SV1 at Clermont stay on C53 at DSO or does it move to C52 - where it will also bump into one of the mixes on Whitehead after DSO ?

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Clermont Carn Saorview transmitter
Monday 20 August 2012 11:50AM

That Clermont move from 53 to 52 will add to the challenge Peter... who do I call to tell them not to move it - and wind up the power while they at it ? LOL

Is NIMM on Black Mountain going to be Vertical or Horizontal polarisation ?

Nice explanation of 'lift conditions' by the way - appreciated... it had never occurred to me that it was interference caused by an even more distant transmitter.

It doesn't explain the occasional badness on C33 from Divis - UTV etc - although that is vastly improved since I swapped out a crappy aerial and put a masthead amp up there.

BTW - my background is telecoms & IPTV hardware & software with some CATV history but I never studied the dark arts of RF much !

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Clermont Carn Saorview transmitter
Monday 20 August 2012 12:37PM

Ahhh - never noticed that Channel5 came from Black Mountain before... I receive that fine on analogue at C37 from my aerial pointed at Divis - makes sense as they are so close to each other... and obviously both horizontal.

I am hedging my bets with Freesat here - getting a dish fitted very soon as the main TV is Freesat ready.

BTW - a useful bit of info for other folk is about the Triax TR1112 STB I bought as an official SaorView box. It receives the FreeView lineup perfectly as far as I can tell from tests so far - it just isn't officially approved.

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Clermont Carn Saorview transmitter
Monday 20 August 2012 1:16PM

Some other weird science is that despite having nothing pointed remotely towards Larne I can pickup snowy horrible analogue channels on C39, 42, 45 & 49.

How does that work when the only horizontal aerial I have is pointed about 90 degrees away from Larne ?

The vertical aerial is filtered for C52-69 so it must be my Divis aerial seeing the Larne signal quite horribly... I would use Larne for FreeView except its only going to be FreeView 'Lite' come DSO.

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Clermont Carn Saorview transmitter
Monday 20 August 2012 4:47PM

Saorsat is an odd beast alright with that spot beam... clever stuff them satellites !

I can't see many folk going for a 2nd dish etc - most folk will try the funky adapters and LNBs for Sky/Freesat dishes that seem to be working OK with a Diseqc switch and so on - but thats really only viable for a single screen - which is probably OK.

Not sure if SaorSat will have HD content either due to its small expected penetration.

Seem to recall reading that Saorsat was only expecting to pickup a small %age of users in difficult terrain where SaorView would be impossible.

Didn't there used to be a thing where NI and IE subscribers to Sky got RTE1&2 by way of additional entitlements on their smart card - it was determined by customer billing address at registration - or did I just make that up ?

October promises to be an interesting month. I must have a look around for some decent DVB-T/T2 measurement gear - it must be available to hire on short term basis - then I can collect some real information.


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Divis (Northern Ireland) transmitter
Wednesday 24 October 2012 2:54PM

Reporting MUCH improved signal quality from Divis in islandmagee area from early this morning. Avoidance of CH33 nicely prevents horrors of "lift effect" which previously caused severe interference from the Cumbria mast.

Also happy to report that my T2 equipped Panasonic is nicely picking up NIMM albeit with less quality reported by the UI but no visible defects noted yet.

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Clermont Carn Saorview transmitter
Wednesday 24 October 2012 4:56PM

Do I get the prize for most perfect SaorView reception, furthest from Clermont Carn ???

I am in the distant lowlands of Islandmagee - about 50 miles from the transmitter. Before DSO I was unable to get anything digital from Clermont on my setup, but today I just tried it with no changes and its 100%.

I have an 18dB wideband 40 something element aerial (3-stacks), positioned vertically - aimed by way of analog reception on RTE. There is ~20dB gain on a masthead amplifier that I hooked up through a filtered combiner to mix Freeview from a separate aerial into my loft box.

Best part is the TRIAX TR112 STB that I bought also locks onto Freeview signals & all the EPG data looks tip top. The Triax box is only certified as good for SaorView so I was happy to see it consume Freeview as well.

I have some screen shot photos if anyone doubts me - I am rather chuffed with the result as the local friendly neighbourhood aerial man said my efforts would be utterly futile !

The STB reports 100% signal strength and 90+ quality on SaorView so I must have done something right.

Interestingly, I have a DVB-T2 freeview TV which enjoyed the new post-DSO upgrade today but it must be programmed to ignore non FreeView signalling that it detects on the SaorView muxes.

Hope others have similar success - I only went to all this effort in preparation for the next series of Savage Eye, so they'd better make it ;-).

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