1.8 mtr prime focus

[Robbo]

Ahh, I'm looking at the wrong end of the stick.

 

[pipino]

i must say ,very odd looking feedhorn you have there m8,first make sure your dish is not deformed(by looking side way look if you see a straight line all across) in you want to pick up C/Ku band in the same time i advise you to use a proper corotor from seavey or chaparral and forget about the all in 1 LNB ,as the KU band is very poor on those LNBs you will get only C band in more less acceptable quality signal,here you have some pictures of some mecanical bits you can use to modifie your feedhorn holder ,and by experience with similar dishes if using KU band only get an ADF120 from invacom as it has a ajustable scalar ring so you have a chance to fine tune your F/D...best regards

 

[bostephen]

I set this 1.8 mtr dish up with a MTI C120 KU band lnb.
The result is not good.
My 1.2 channel master with the same Vantage 221 receiver outperforms it!

The thing looks to me like it doesnt have a good depth, with that the focal point seems to have be displaced (either up or down). I use a similar setup, but mu lnb is long and provides for focal adjustment. Your lnb doesnt!

 

[bobon]

I think i found the problem, today i put some string across the dish face.
when i did it last time i only put string from top to bottom and side to side, this time i put some at angles and found that one of the angled strings was approx 1/2 an inch from touching the others.
It looks like i will be taking it to the tip.
Would it be possible to use the polar mount with a 1.8 Channel master offset dish?

 

[CROSSBONES]

Would it be possible to use the polar mount with a 1.8 Channel master offset dish?

It could be adapted, but the question is, would the mount be strong enough? As the Andrews 1.8m dish is very heavy!!

 

[satelliteman]

Would it be possible to use the polar mount with a 1.8 Channel master offset dish?

Take a look at this recent thread, RE: polar mount - might be of some interest.

http://www.satellites.co.uk/satelli...ter-1-80-upgrade-costa-blanca.html#post847955

 

[Channel Hopper]

I think i found the problem, today i put some string across the dish face.
when i did it last time i only put string from top to bottom and side to side, this time i put some at angles and found that one of the angled strings was approx 1/2 an inch from touching the others.
It looks like i will be taking it to the tip.
Would it be possible to use the polar mount with a 1.8 Channel master offset dish?

That can be straightened out without too much trouble, but there are still the shallow surface and the feedhorn limitations.

Bury it in the garden as a duckpond.

 

[Channel Hopper]

It could be adapted, but the question is, would the mount be strong enough? As the Andrews 1.8m dish is very heavy!!

A prime focus polarmount of any type will not work easily as an offset mounting system.

 

[bobon]

These pics probably show why its bent,didn't realise at the time.
I was more concerned about the actuator getting damaged.
How would i straighten it?
The depth of the dish, after measuring it again with a proper straight edge is 9 and a 1/2 inches, the distance from the centre of the dish to the opening of the waveguide is 31 inches. According to my calculation it should be 32.9, is that correct?

 

[Robbo]

Yep, it's about 0.84m according to the satlex calc.

 

[Channel Hopper]

That garden looks like it needs a duckpond.........