Zone 1 Sky dishes - lots now being installed

JDxtra

More and more around Dublin I see zone 1 Sky dishes (the smaller 45cm dish) being installed. Previously, they'd be fairly rare - but now seem to be the default installed. Anybody noticed the same? Any issues with them on the weaker transponders, during rain etc.?

TAFKAlawhec

Not a Sky Zone 1 dish per se, but until recently I'd been using a 45cm "universal" offset dish for reception at 28.2 E.

The Astra 2E/F/G satellites give out plenty of grunt especially on the UK & Ireland beam. The 45cm dish is more than adequate for this, SNR levels ranging from 14db to 17db. For the European beams, 2E & 2F are again fine, just a slight bit down on SNR levels. Usually the weakest signals come from 2G, due to the European footprint actually focused on Central Europe rather than further westwards, meaning Ireland is further away from 2G's footprint centre. Even then it's not normally an issue. SNR at worst on a clear or even cloudy but dry day is around 12db to 12.5db.

When rain strikes, the LNB I use is one of those narrow neck ones that are often used for multi-lnb set ups that just happened to match well with the dish compared to a few others - in normal rain the SNR falls about 2db while in heavier rain there might be a 3db fall (this is to be slightly expected as losses due to raindrops on the LNB cap tend to be worse for "narrow LNBs than for those with larger caps) - but even on the 2G European transponders, reception is very rarely lost. In about two years I've lost reception on channels to rain fade only once, and it was so heavy it still wiped out most of the spot beam channels!

In the past a Zone 1 dish would have been hopeless in most if not all of Ireland, especially in the last 2-3 years of Eurobird 1/Eutelsat 28A's service where it clearly had power supply problems, so much so that even a Zone 2 dish at my home, accurately aligned, was cutting out some Eutelsat transponders during heavy showers. The old European North and South beams on 2A & 2B, whilst stronger than Eurobird 1, were still weaker than the European beams on the 2E/F/G satellites today. Once the new satellites went into service, some broadcasters took advantage by changing FEC rates to allow for greater data capacity per transponder - usually this would require a better SNR but the output powers of the satellites took care of that. ITV (and later also the BBC) changed one transponder to 8PSK 3/4 from 2/3 and even did a test with SES to see if 5/6 was possible or really pushing it - seems it was the latter case as 3/4 was as high as they'd eventually go. IIRC all the original Sky DVB-S transponders that were QPSK 2/3 were changed to 5/6.

I'd reckon that on some of the western fringes of Ireland like Mayo and Kerry, a Zone 2 dish would be keeping it safe, but if a 45cm dish does fine in wet and dull Tyrone, I can't forsee a Zone 1 dish, as long as it is properly aligned, being too small in Dublin or anywhere on or near the east coast. I have a Zone 1 dish myself stored away in my home, but never been brought out to use - I do know however that they're a good bit lighter than a Zone 2 dish, it can be fitted to a wall quite quickly with a low profile where possible, and can be attached on a pole up to 50mm in diameter with a respective clamp whereas Zone 2's can only really go on a 32mm pole or thereabouts. The size for storage helps too, as is the cost.

JDxtra

Thank you so much for the detailed response and explanation, appreciate it.

TAFKAlawhec

No problems.

I've attached a pic of a temporary setup I had back in early Spring. Dish on the left is the 45cm dish in question aimed at 28 East. On the right is an 80cm dish aimed at 9 East to test reception of Saorsat. LNBs are an Amiko "narrow" Ku Band for the small dish, and a Triax Ka Band model designed for Saorsat reception with twin outputs on the larger dish, fed into a Technomate Diseqc 1.0 switch onwards to the receiver in the house.

Reception of all services from the European and UK/Ireland spot beams from all three satellites are solid. I think the transponder that carries NHK World had the weakest SNR IIRC yet didn't drop out in the rain - any rain fade tended to affect loads of transponders once there was a tipping point that would relate to about 1% of the most intense showers we'd know off in Ireland - as you might be able to tell, the photo itself was taken after a shower! FWIW, reception of Saorsat on the 80cm dish was very solid - notably, even in heavy rain reception of the Saorsat transponder only went down by a max of 2-2.5db, well above the minimum threshold. I didn't test it with any other dish, but I reckon it would work fine either as a moderate LNB offset on an 80cm or as the prime focal point on a 60-65cm dish - the 45cm would likely be pushing it. Of course, given Saorsat's nature, reception dish size will vary across Ireland given that the footprint is (a) tight & interference limited, and (b) not formally published by 2RN or Eutelsat - knowing where the beam centre is aimed at would be a good help.

Setup is now down due to new work being done in the back garden where the dishes are, which included the buried coax cables being removed. At present I just have terrestrial TV (Freeview & Saorview) but depending on time & weather, I have a Wavefrontier T90 in storage to try out which should have a 28 East LNB hanging off it when permanently set up, with at least three additional standard offset dishes helping to cover the gaps for a range from 53 East to 30 West. Might get it done before the end of the year but I've other home projects to complete first, so it might have to wait until next year.

I'm rambling here, so until maybe later, that's enough for now.

MBSnr

I've one box on a long run with two joints and really noticed the change when ITV went to 8PSK 3/4. In rain I'd see issues with picture break up. The short run to another box is fine. I ended up getting this https://www.amazon.co.uk/gp/aw/d/B002BZIHLG which seems to have helped the issue. Although the box didn't indicate a problem with that TP (signal or quality) and I've a combiner DTT and Sat on that cable.