Motorised Skew - a solution for big dishes?

pjgregory

I am a new member on this forum, but I have spent the last week in reading a lot of posts about installing Big Dishes. Like may others, I am trying to get Astra 2D for BBC.

Living in central Italy (80km south of Florence), I know it is not easy. My exiting 2.4m IRTE dish is not working. While I have now bought the parts recomended here (Pace 2600 digibox, Invacom Quad C120 LNB etc., I am facing up to the reality of having to install a 3.1m or even 3.8m dish to make it work. Assuming I can find out where to buy it, how to transport it and how to assemble it to the accuracy required, there is still the problem of aligning such a monster.

Setting the feedhorn for the correct focal length and pointing it exactly at the center of the dish should only need to be done once during assembly. Pointing the dish at Astra 2D can be done from the AZ/EL screws at the back. But what about the skew of the LNB. It is only through reading post here that I have come to realise just how important this can be. One contributor (Snap) has talked of sub degree adjustments. How do you do this?

Well there is one photgraph of a guy standing inside the dish. I could hire a cherry picker and operator for a few days or build some sort of mobile scaffolding gantry.

Can you buy, or has anyone tried to make a motorized LNB mount that would allow you to rotate the LNB electically to sub-degree accuracy? Although it first sight it might appear total overkill, the other options for a non professional installer might just be worse.

PJG

Turok

Hello!
first you must look what scew angel,
you must set,your lnb
of 28,5 for your location,on this website .you can do this
_www.satlex.de

type in your coordinates east and west degrees,select the satelite ,and after calculation,you see a graphical diagram,of your lnb scew position!
for fine adjusting the sceq,you need a polarizer,with 3 conection cables!
but,i dont know exactly the dishsize is necersary,in your ara for bbc!
a polarizer,takes a proximently 0.5 db,maybe to much,when the signal is very very weak!

,so i dont think you need one,fine adjusting manually,maybe the better way!

invavom lnbs,was often tested,in out of footprint areas !
but,in the meantime,you get better lnbs for weak signals,
i got i report,from east germany,that it was not posible to reveive bbc with a channel master 1,80 m,and invavom lnb,changed to inverto,and the picture ,was here,with the exactly same antenna!
it sounds crazy,but,when i see the signal,difrents,now on my gregory,since i changed from invacom,to inverto,i can belive it!

the last option you have,you buy lnbs ,that are optimeized,for 10-11 ghz range,also avalible for 12 ghz optimeized!

this lnbs,are not avalible here in europe,check Ebay usa ,some dealer have it in stock for a couple of $
the problem,you have ,a limited freqency range,but optimeized for it!
greetings from your nabour country!
good luck!!

paul682

hy mi friend

pj gregory

the motorized skew could be one of the solution
but the real problem for astra 2d

is to make the fine pointing both of dish and lnb ( skew )
if u make a real nice pointing with a 3,7 m

u 100% receive all astra 2 d
there in FIRENZE

iam 300 km more south east of you
and i receive with 3,7 meter fiberglass
all the 2d transponders

with only 2 tp that i dont receive 10906 v and 10936v
the other are ok
so no problem
from your position with 3,7 m
because you are more close of the footprint of the 2D
respect my position
ciao
PAOLO

pjgregory

Salute Paul68

I live near Monteulciano (about 150km west from you) with a IRTE 2.4m Prime Focus Dish and do not get Astra 2D.

I have made this map of recent reception reports. There is no good reception further south of lattitude 43 degrees. I now think that I must now replace my dish with the same as yours - 3.7m Prodeline. Did you buy this in Italy or import it directly from the USA?

My idea about rotating the LNB and feed horn with a stepper motor is due to the difficulties I can see with reaching the LNB inside such a large dish. The adjustments for elevation and azimuth can be done more easily from the ground at the back of the dish.

Ciao

PJG

Attached Images

Astra2D-Italy.jpg (137.8 KB, 19 views)

paul682

i am agree with you

more south of 43 parallel i think that the reception

going very difficult

if u want i can sell it to you at 2300 euro

the model 1374 - 990 fixed az - el

let me know

because i have not

the motorized model because the polar mount is too

small and not large

example

normal arc at me was 91,5 east / 61 west

POLAR MOUNT PRODELIN

62 east / 27, 5 west

you know that the polar mount from prodelin
was ridicuolous

is better for you to install the dish fix

let me know!

ciao
i am an installer , here!!!
if u want i can send some photo of 2d very soon

pjgregory

Salute Paul

Please download my VCard with my e-mail address so that I can contact you. I would be interested in buying a Prodelin dish.

PJG

Roddyb

PJG

Another source of dishes may be DIEM Technologies in Genoa. They have a website and are really friendly, helpful people, despite being a large telecoms supplier. I bought my 1.8 CM dish from them at a very reasonable price compared with suppliers outside Italy. They also do larger dishes.

Sorry I still cannot access your Vcard.

Roddyb

paul682

HY MY FRIEND
AND HY RODDYB

i try to send u A private message

but you have this function closed!!

PLEASE send you to me a PM
and after i can contact u direct

thanks again
ciao

pjgregory

Hi roddyb and Paul682

It appears that I am not allowed to communicate with anyone as I have only been a member of the forum for 2 weeks. That is why we cannot exchange private messages. One of the moderators - ROLFW- told me to enable my vcard which would allow you to download my e-mail address.

I have now done this several times and although ROLFW can download it, you cannot. In addition, I cannot see your "Contact Info" tabs on your personal pages so I cannot contact you either. I guess the ban on talking to new members extends to Vcards as well. Perhapse you can contact the moderators to find out what the problem is and what we need to do to resolve it.

PJG

gio2010

Hi Turok

In your post you refer to an LNB called Inverto.
Could you please tell me which one do have?
The twin, the mono or the quad?
Thanks for your hepl

Gio

Topper

Paul682 obviously does not know where to look

Click on pjgregory's name on top left of post

Click on View public profile

click on Contact info tab

click on Download Vcard

It could not be any easier

__________________
War does not determine who is right, it determines who is left!

Formerly toppervte33h
whose six pack has turned into a keg

Help support this web site by making a donation
Or use other options to help support Sats UK
Show Your Support
by clicking the button

Thank you.
Freddie Flintoff is back

Turok

i have the new interto white tech 0.3 single and twin,both perform vey well!
but its dificult to fix on gregory,coz you crashed with the lnb arm!
dont buy,the old invertos, (oem made by mti),there performace is misarable!

only white tech is good,but in german area,you got not in normal stores,only some big sat dealers,in germany has it in stock!