Advice Needed 1.5m GIBERTINI or 1.8m Raven?

[mapperuo]

Dug out the specs of my current dish:

• Gain (10,7GHz) 40,9dB
• Gain (11,7GHz) 41,7dB
• Gain (12,7GHz) 42,4dB

So the CM or Primesat 1.8m is about 4db higher. Not sure what that is in percentage of signal but it sounds like it's worth the upgrade.

Just need to decide more expensive, heavy CM which everyone says is amazing, or the cheaper, lighter Primesat/Precision. If the gain is the same or atleast almost close it would make sense to go cheaper and have the install be easier with a lighter dish but I cant say I wont ever regret not getting a CM GAH! Tough choices..

 

[PaulR]

Dug out my CM stuff and found this PDF brochure for the CM 1.8m OS dish. As can be seen the centre band gain in Ku band (11.85GHz) is indeed 45.5dBi.

Personally I'd still go for a CM/Raven/Andrew!

 

[mapperuo]

How many folks do you think it would take to lift a CM 1.8m onto the stand those who have handled one?

 

[Archived-1]

How many folks do you think it would take to lift a CM 1.8m onto the stand those who have handled one?

Two people would be ok if its at ground level, I will install the pole then mount then dish, hope you make the right choice of dish.

 

[Huevos]

Dug out the specs of my current dish:

• Gain (10,7GHz) 40,9dB
• Gain (11,7GHz) 41,7dB
• Gain (12,7GHz) 42,4dB

So the CM or Primesat 1.8m is about 4db higher. Not sure what that is in percentage of signal but it sounds like it's worth the upgrade.

Nowhere near 4dB gain in SNR. Those figures are gross signal. Maybe the dish picks up 4dB more signal but the bigger dish also picks up a truckload more noise. The net effect is a much smaller increase in signal to noise. Going from 1.3m to 1.8m is not even a 2dB gain. On my 28E setup I have just switched from a 1.8m to a 1.1m dish and the difference is less than 3dB.

BTW I've got a Gibertini 1.5m and there is no way that would go on a USALS motor. Even the 1.2m Gibertini is far too big for a USALS motor.

Also I work on 1.8m PF and offset dishes on a daily basis. In theory there might be a difference, but in practice you won't see one. Changing from one LNB to another has a much greater effect.

 

[Vipersan]

How many folks do you think it would take to lift a CM 1.8m onto the stand those who have handled one?

Not so much the weight ..as the width of the dish ..plus the lack of a 3rd hand to get bolts in place whilst the reflector is being offered up to the mount..
Recently went from a 1.25 to a 1.5 ..and could handle the 1.25 easily on a windless day by myself ..
the 1.5 ..simply wasn't doable on my own so enlisted help ...
A third hand..
A 1.8 would be more difficult again ..and would suggest a 4th hand needed ..ie ..
2 people.
rgds
VS

 

[Archived-1]

I will just fix one nut and bolt to the dish so your not trying to put one through it will then hold its own weight with a little support for 1 person, having said that I am quite fit and 46 . if you and your friends are pensioner, arrange a coffee morning.

 

[sonnetpete]

if you and your friends are pensioner, arrange a coffee morning

Ahem......some of us are near to pension age...and still quite mobile you know.......though I couldn't handle a 1.8M dish by myself....

 

[Archived-1]

Yes pete, it depends on age and fitness etc etc, I am sure I could fit it myself if I tried but I feel as fit as a fiddle, but I wont try without a jack lol,

 

[mapperuo]

I'll have a friend to help, we may still have a coffee morning though, Biscuits sounds good over a box of dish parts.

Pretty sure Ill go for the Channel Master, I'll regret it if I don't. I still cant help think how neater the prime focus dishes look pointed up into the sky compared to the offsets though...

 

[Archived-1]

I would have a good shop round for prices mapperuo.

 

[mapperuo]

I would have a good shop round for prices mapperuo.

Absolutely will be doing so. And if anyone has any suggestions on ideal places, I'm all ears

 

[Archived-1]

I am awaiting a few prices for a polar mount if they are cheap on the mount I will let you know.

 

[mapperuo]

Been searching at prices for a while, Can certainly get a 1.8m dish a lot cheaper than I thought. But they never seem to include shipping, and of course it's just the dish. You then need to buy the polar mount (as you say above!) the lnb, ground mount if not using a pole in concrete and motor.. Whilst expensive I still see the appeal of an expensive 'Complete kit' on the superstore which has free shipping also.

I'll continue the hunt though!

 

[sonnetpete]

@ Mapperuo. Laminas do a 1.8M with a polar mount, however there isn't a UK distributor that I know of. This is the guy I got my 1.2M from :

http://www.2galli.fr/boutique/fiche_produit.cfm?ref=AS1800POL&type=30&code_lg=lg_fr&num=21

You'll see that although the price will be roughly £830 (£ = €1.20) you'd have to contact him to ask for a quote for shipping. He also stocks a suitable ground mount but at just over £300 it seems a bit steep to me. You could also contact Laminas in Poland direct.

http://www.laminas.com.pl/page_eng/home.html

Last time I did there was an English guy working for them who replied to my email.

 

[PaulR]

The problem of the gain figures between the CM/Raven offset dish and the Precision prime focus continued to trouble me. Eventually I did what I should have done to start with and went to the Precision (now Elite Antennas) web site and downloaded their catalogue.

And waddya know. The Google answer is wrong and mid band gain of the 1.8m Precision dish IS lower than the CM dish. Specifically the Precision EPR18KUE is 44.7dBi against the CM180's 45.5dBi.

So the physics is correct after all.

I'll attach the Elite Antennas catalogue for reference. See page 13 for the data.

 

[mapperuo]

Last time I did there was an English guy working for them who replied to my email.

Thanks sonnetpete! I'll give him an email and see what we get price wise.

And waddya know. The Google answer is wrong and mid band gain of the 1.8m Precision dish IS lower than the CM dish. Specifically the Precision EPR18KUE is 44.7dBi against the CM180's 45.5dBi.

Excellent fact finding! Thank you. Hopefully this will help anyone else wondering the same.

 

[sonnetpete]

Thanks sonnetpete! I'll give him an email and see what we get price wise.

From what I remember (it was over three years ago) he said it would work out cheaper if they could ship two. However that was for a 1.2M...

 

[Channel Hopper]

And waddya know. The Google answer is wrong and mid band gain of the 1.8m Precision dish IS lower than the CM dish. Specifically the Precision EPR18KUE is 44.7dBi against the CM180's 45.5dBi.

So the physics is correct after all.

More to do with the area of the two reflectors, the Precision is 1.8 x 1.8, the CM is almost 2m x 1.8m.

 

[Captain Jack]

But from satellite's and LNB's point of view, the offset appears as 1.8 x 1.8... doesn't it?