Different dish signal gains

Messages
47
Likes
0
My Satellite Setup
no dish
My Location
spain
#1
Hi.

Preparing to setup a new satellite system,I found the following specifics about signal gain:

Gibertini 1.5m offset: 43.3db
Irte 2m prime focus: 44.6db
Irte 2.4m prime focus:46 db

Can I ask the experts (snap?) how significant are these differences in real practice?
 

dxsat

Specialist Contributor
Messages
745
Likes
70
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
#2
Big difference, just a fraction of one db gain can mean the difference between nothing at all and a watchable picture.
Be aware, however, that some manufacturer's figures are absolute maxima, measured under perfect conditions, and the real gain in the field can be lower.
The most obvious example of this is with FortecStar, who promise a gain of 48.4 on their 2.4m prime focus. This is at a frequency of 12.5 ghz, which is at the highest end of the bands a dish can receiver. Most honest manufacturers give the value at mid-band, 11.5ghz, a lower frequency which returns a lower gain figure. I know from practical experience this particular FortecStar dish delivers nothing like that.
Most footprint maps for Spain will show many areas such as mine as needing a 2.2 to 2.4 metre antenna. You can get a reasonable result with a 1.8 metre in these areas, but it has to be a top quality fibre based dish such as ChannelMaster or Prodelin 1.8m, which both have a midband gain of 45.5. The 2.4 metre ChannelMaster Offset has a gain of 47.6.
I know of someone in Madrid with the 2.0 metre IRTE who has performance similar to the Gibertini 1.5 metre. This could be down to choice of LNB or receiver, however. She loses BBC2 early to mid- evening.
Famaval (so- called "Portugese dish") have a similar gain to IRTE.
All prime focus dishes have lower gain than offset dishes of the same size.
The difference in practical terms between a Gibertini 1.5m and a Prodelin 1.8 m is about 3 to 4 hours more viewing on BBC 2 round here.
You have to take a view of the best cost / size / gain balance.
The very best dishes are pretty expensive, but have professional performance ( Andrew/ChannelMaster are used by broadcasters) and are mechanically more robust.
Remember many dealers and installers will try to sell you a lower cost dish as they are dirt cheap at trade prices.
Where are you located?
 
Messages
47
Likes
0
My Satellite Setup
no dish
My Location
spain
#3
Hi snap and thank for your reply.
I am also located near Madrid.
As I currently have no dish I was looking for the best cost/gain solution,exactly as you said.
I'm "afraid" of Invacom lnbs,as I know from friends' experiences that some units don't perform as well as others(that is,you have to be lucky enough to get the really good ones).

Looking at the maps,I have already excluded the Gibertini 1.2m offset(rated at 41.3db).Am I right?

My plan is to add a polar mount and actuator to get other sats too.Can this affect performance on Astra2d?

From what you said about offset dishes,can a Gibertini 1.5m offset be compared to a 1.8m prime focus?
 

dxsat

Specialist Contributor
Messages
745
Likes
70
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
#4
The only problem with Invacom LNB's is that the single version is relatively poor, and the 'H' version is much the same. The only ones to go for are the 'F' versions (F = flange) , the twin and quad. Your friends may have tried the poor ones. Invacom quality control is better than other manufacturers, so if you choose the QDF 031 or TWF 031 you can be sure of getting a good unit.
I've tried many types of LNB and these two work the best.
You're right in assuming that a 1.5m Gibertini and a 1.8m prime focus have similar gain, with the advantage towards a 1.8 m. Depends on which one you are thinking of.
Using a motor should not affect performance, provided the initial setup is done properly.
 
Messages
47
Likes
0
My Satellite Setup
no dish
My Location
spain
#5
Hi again.
I'm sure every european fringe-area resident would like to "teleport" you to their town in place of the local installer!

I'm not a fan of regional news,so of all the channels I'm interested only in one viewable version of BBC1,2 and ITV.

So,as I need fewer transponders,can this influence my setup?
What time in the morning do signals come back?
 

dxsat

Specialist Contributor
Messages
745
Likes
70
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
#6
Thanks!
In Madrid the low point is from 11pm till about 4-5 am.
A 1.2m dish will receive everything in the mornings from about 6 am till lunchtime, depending on location.
A 1.5m will extend these hours but evenings will frustrate.
When I was using the Gibertini some days BBC2 was Ok till 10.30, others it would break uparound 7pm. This kind of thing can drive you crazy.

If you are looking for BBC2 all day a 1.8m is essential. In the winter months to the north of Madrid all channels are 24 hours.
Good areas for BBC 2 are: Venturada area, Manzanares, Urbanizaciones Santo Domingo and Ciudalcampo. Poorer areas are around the south west part of the M40, from Torrelodones to Getafe. In these parts vertical transponders are better, for BBC 1 and ITV.
If you want BBC channels there are few options to cut corners, unfortunately. BBC HD is easy to receive here.
 
Messages
47
Likes
0
My Satellite Setup
no dish
My Location
spain
#7
Thank you snap.
The picture is getting a little bit complex,so I will put my project on a hold for the moment,waiting for your signal readings report you announced on another thread.
As you talk about bbc2 being difficult,I assume you meant bbc1 and itv1 are more easily receivable.
 

dxsat

Specialist Contributor
Messages
745
Likes
70
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
#8
That's right, BBC 1 and ITV are much easier, if you are not too bothered about which regional service you watch. A 1.5m dish will get you these 24 hours.
 
Messages
47
Likes
0
My Satellite Setup
no dish
My Location
spain
#9
That's good to know!
After a bit of study,I found out that bbc1 and itv1,because carry many regional variations,will always be available on some of the easier transponders,no matter what kind of channel shuffle should happen in the future,as I don't care about a particular version.
The only problem will remain bbc2 owing to its fewer
variations,so it is only carried in two transponders,unluckyly among the weakest.

This makes me believe maybe the bbc did it on purpose,knowing that bbc2 would be the only main
channel that could be "protected".

Anyway, when will your signal readings be ready?
If it's confirmed a 1.5m will give bbc1 and itv1 24 hrs, I think that's good enough for me.
Thanks.
 

dxsat

Specialist Contributor
Messages
745
Likes
70
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
#10
Can confirm that 1.5m is good 24 hours for verticals in Madrid (only exception heavy rain)
My study on 2D horizontal signal will have a meaningful result by the end of March , I hope, some six months after I started. I'm concentrating on BBC2 on 10773H, the one that carries BBC2 England and BBC1 London, CBBC etc. It's the most important transponder for many people in this area.
 
Top