Dish size

[7mdish]

I'm curious to understand which dish sizes are used by public or private main broadcasters like BBC or ITV in UK for example (or RAI in Italy) and the same in the big earth stations.
As I know, in the dawn of satellite TV TV during the 60s when satellite reception was totally out of the game for any private user, earth stations used dishes around 25 meters or more! Yes you read correctly: 25 meters.
In that old era, I believe that few broadcasters have their own satellite dish, and most of them were supplied by earth station when needed, or maybe they got satellite signals through Eurovision terrestrial circuit in S band (around 2 GHz).
Obviously The situation changed in the 80s, and now all broadcasters have satellite dishes, but I don't know what are the most used sizes..... maybe 3m or 3.7m or more?
Same question for the earth stations. They surely use larger dishes but I have no idea.
Anyone have specific information about this topic? Thank you.

 

[Terryl]

I don't know about Europe or the UK, but here in the US, we use at least a 20 foot dish on "C" band, this to prevent weather fade due to rain, even bigger for the states with a lot of snow.

Usually one dish per satellite, and the further North you go the bigger the dish.

And we have quite a lot of receivers to supply a signal to.

 

[7mdish]

Oh 20 foot dishes.... it means more than 6 meters!
I'm not surprised about so many receivers, and, more or less, I know which boxes are used for distribution or contribution feeds.
But I did not know that so big dishes are used. Also, you mentioned one dish for each satellite. This is another interesting topic I believe.
No motorised one? No rotating feedhorns to optimize skew? No or few Ku band operations?
I thought that such motorised dishes was used to be able to get every possible satellite positions.
Anyone has any update about the situation in Europe? Thanks.

 

[Channel Hopper]

https://sms-teleport.com/antennas/

 

[gap30]

 

[7mdish]

So.... what a setup!! I did not realize that a Teleport could have a so extensive type of dishes.
It is interesting to note that they have two separates dishes for C and Ku band from the same position!
And some very large dishes pending, probably ready to be aimed to a satellite by request.
Now I have a good idea. Thank you so much for your advice.

 

[Terryl]

And in a few months/years they will have to move them to a few new satellites, and re-tune all the receivers to new transponders, all because of 5G going in, big mess.

 

[Fisty McB]

Within the UK at least, for terrestrial transmitting stations where certain programming or backups (e.g. BBC Satback on 27.5W) are fed via satellite, they tend to use quite large fixed prime-focus satellite dishes that would appear to be at least 3 metres in diameter, but in some cases I have seen some smaller (still prime-focus) dishes used for national DAB feeds, probably in the 1.8 metre range which often have a cone shaped shroud covering not just the LNB but also the parabolic dish surface.

When the Bilsdale mast was damaged beyond repair last year, some of its relay sites as well as a few temporary sites that sprung up either were unable to use another terrestrial UHF source to relay or couldn't have done for technical reasons (e.g. wrong local region), so those affected had to be provided with a satellite feeds - the BBC Satback for Multiplexes PSB1&3 and a temporary "Digital 3&4" PSB2 multiplex transmitted at 28E. From what I've seen on MB21's transmission gallery, such sites needing these feeds for the three PSB multiplexes used domestic offset satellite dishes & LNBs, (two at each site) in the range of 1 to 1.2 metres in diameter.

As a rule, the rain fade margin for satellite feeds to TX sites needs to be far greater than what is deemed acceptable for domestic, household satellite reception so that even the heaviest of expected rain showers that occur each year still doesn't interrupt reception of the satellite feed.

In terms of broadcasters themselves, I remember being an eager teen back in the 90's once being invited to Ulster Television's (UTV) studios at Havelock House in Belfast and noticed the huge satellite dish on the roof that was prominent from the car park & near the front entrance of the building which at the time had the station logo on it - it had to be at least 5 metres in diameter and looked like it was motorised. Since UTV moved out of Havelock House to the City Quays 2 building in the city, the big dish (minus station logo) was left behind, and can be seen in the second photo down in the link below. There was nothing comparable at BBC Northern Ireland's Broadcasting House in the city centre, at least at ground level but I'm sure they'd have had something on their roof and would still do.

Havelock House: Residents welcome rejection of demolition plans

Residents welcome Belfast City Council's rejection of plans for 270 apartments.

www.bbc.co.uk

In the Republic of Ireland, all the main TV & radio feeds for national stations (Saorview DTT, RTÉ & Today FM for radio & possibly Newstalk as well) are sent to the main transmitter sites via either landline or microwave feeds, the only network feeds done via satellite are for a few regional or quasi-national stations that use the same Intelsat 901 satellite as that used for the BBC SatBack service at 27.5W - additionally, Northern Ireland's Q Radio also uses this satellite to feed its transmitters for its non-Belfast advertising regions. Prior to DSO in 2012, in the last few years of analogue TV operation, feeds from 28E were used for backups at some sites which at times proved troublesome, as reception would sometimes be lost and various messages from the Sky digiboxes being used would pop up!

 

[7mdish]

Very interesting topic.
I'm not able to test now, but until last year I received only BBC Satback at 27.5 West.
Did you say that other stations in Ireland use that position now? Could you please explain better? Have you all parameters (frequency, symbol rate....)?
Waiting for my new dish yet, I'm facing a big big delay but hoping soon. When it will be here, one of my first test will be on that satellite.
Back to Teleport dishes, it is so fascinating to discover how big are those dishes.... fantastic.
Thanks.

 

[Fisty McB]

Did you say that other stations in Ireland use that position now? Could you please explain better? Have you all parameters (frequency, symbol rate....)?

All available at - Home - FlySat Satellite Chart

Since these stations have very, very low symbol rates (Spirit Radio has an SR of just 83!) I suspect all of them except the Q Radio NI feeds are out of reach of most if not all current domestic receivers.

 

[7mdish]

Symbol rete of 83??? Never heard before.
Which receivers are used? I can test with professional boxes (maybe), or TBS5925 PC card.
But it would be useful to know what type of box they use. Thanks.

 

[Raystorm]

https://sms-teleport.com/antennas/

They're mine!! Smallest is 1.8m boggo TVRO, largest is a 13.5m Ka-band with monopulse tracking, with every band and size inbetween!