Inside surface of Feedhorn - Shiny or dull?

[Channel Hopper]

Well the reflector you have is definitely the same as the 2194 series (the 3180 is similar but for a higher frequency, and so the mounting points and backplate are usually made to a higher specification).

But the feedhorn and arms are from a receive-only antenna, and it may be these that are the wrong dimensions for the reflector.

The easiest option is probably to enlarge the scale drawing you have of the 2194, and measure the arms with a vernier caliper, and then fabricate a proper set for your dish if the ones you have are much different.

Nice dish though, you will be impressed with the performance once it's properly assembled.

 

[tmbp]

Hello there,
Today I made some more tests. While on the ladder I notided a manufacturer name on the dish - "Northern Satellite Corp" model: NSC 18-1.
I tried finding some info on this company but cannot find any references on the google.
Anyway, I stuck some pieces of mirror on the dish to find the focal point - with some degree of success, but am still not 100% satisfied on the setup, so next week will try another LNB, and probably a different feedhorn. Presently using the Invacom with the original feedhorn, maybe the inverto will be the alternative - but if you have any other to reccomend I would be happy to have your input. I am trying to get Astra 2D - more specifically the BBC channels.
Will keep you posted throughout my tests.
T.

 

[futumsch]

I recognised 'Northern Satellite Corp" as Norsat - I've bought LNAs from them before. I was just looking up a link for you __www.norsat.com/company/history/.. and it mentions how the president developed the prototype dish, that helped launch the company, from chicken wire and foil, LOL. Well, the guy must have done something right to get the company on its feet but I certainly hope your dish performs better than that may have turned out tmbp. No feathers sticking out the back of the dish are there?

 

[tmbp]

Hey, thanks for that information - I wrote to the company and they do not recognise the product and say it was not produced by them! Anyway - I will use the prodelin type 2194 as the template for the feed parameters, what I would like to ask is if anyone thinks the Andrews feed horn could be a technical upgrade for the old feedhorn that I already have? I suspect the one I have is not successfully illuminating the dish area, because the strength of the signal is lower than what I get on my 1.20m dish.
T.

 

[Channel Hopper]

The Prodelin dishes had two f/d ratios 0.6 and 0.8 depending on the age of the design.

I think Channel Master had only 0.8 in their range, so an older style Prodelin dish will not support the Channel Master feed.

 

[tmbp]

Is there any way I can check the f/d ratios myself? I am at a loss to guess what it is. In any case, I certainly think I have to change the feedhorn, It seems a bit small for the dish, and no amount of moving it around and fine tuning will bring the signal strength up further than around 80%.

 

[antenna1]

This dish is one of the old northern satellite smc dishes from the 1980's they sold the dish in other sizes 90cm 100cm 1.2m they sold them on there own and other companies sold them with receivers like the connexions receivers these dishes have nothing to do with the company norsat that makes lnbs. The company Northern Satellite Corp have not been about for years alot of their dishes where sold in the uk.

 

[Channel Hopper]

This dish is one of the old northern satellite smc dishes from the 1980's they sold the dish in other sizes 90cm 100cm 1.2m they sold them on there own and other companies sold them with receivers like the connexions receivers these dishes have nothing to do with the company norsat that makes lnbs. The company Northern Satellite Corp have not been about for years alot of their dishes where sold in the uk.

Echostar also sold a branded Prodelin dish (90cms) with their own 'horrrible' polarmount (with plastic bush bearings), but this was well over 10 years ago.

 

[Channel Hopper]

Is there any way I can check the f/d ratios myself? I am at a loss to guess what it is. In any case, I certainly think I have to change the feedhorn, It seems a bit small for the dish, and no amount of moving it around and fine tuning will bring the signal strength up further than around 80%.

Well since the number 2194 is probably an upgraded (high wind ?) version of the the 1194, and the vertical dimensions of the reflector are identical, I would suggest the feed location would be roughly the same and an 0.8 f/d ratio feed (39 degree type is the right one for the reflector.

_http://www.gdsatcom.com/Prodelin/Technical_Docs/feed_location_drawings/td0321.pdf

 

[Turok]

Hello!
a friend here,has a northern satellite dish with 1,80 m,i dont have any information about this company?
no datasheets nothing,also he has no orginal feedholder,and made one in the iron factory,the antenna looks very stable,but we dont find information about this dish,maybe satcom from, chicago can help!

 

[Satcom1]

Great dish should give you good performance on both C band and KU.

The feedhorn with Invacom lnbf are a good match for this dish.

If the mounting arms don't look like they came with, then you can go through the attached pdf manual to determine where they should be.

This does look like it was made by Channel Master for oem.

If you side mount a Panorama C band lnbf with a flat Scalar (Not Conical) you will get pretty good reception. NIX the C/KU LNBF combo.

I have heard that the wire mesh in some of these old dishes did go bad due to the styrene. Most likely problem is plumb&level, Elevation and Azmuth errors. Skew should be Zero.

 

[Satcom1]

Guy in LA had very good performance on 1.2m offset.

 

[antenna1]

Yes i remember those dishes and mounts i remember you also buy them as a pack with the lt-8700 receiver

Echostar also sold a branded Prodelin dish (90cms) with their own 'horrrible' polarmount (with plastic bush bearings), but this was well over 10 years ago.

 

[antenna1]

No it was not made by channel master at all just northern satellites. The original feedhorn that came with these northern satellite dishes was odd looking it was thin and had a dome shape cover on it. It looked very different from the channel master and prodelin feedhorns,

Great dish should give you good performance on both C band and KU.

The feedhorn with Invacom lnbf are a good match for this dish.

If the mounting arms don't look like they came with, then you can go through the attached pdf manual to determine where they should be.

This does look like it was made by Channel Master for oem.

If you side mount a Panorama C band lnbf with a flat Scalar (Not Conical) you will get pretty good reception. NIX the C/KU LNBF combo.

I have heard that the wire mesh in some of these old dishes did go bad due to the styrene. Most likely problem is plumb&level, Elevation and Azmuth errors. Skew should be Zero.

 

[tmbp]

Hello.
Thanks to all you kind people for your comments, there was a lot to read, and things to chew over, such as the alignment, the feedhorn type etc.,
Satcom1: Do you think the channel master feedhorn would be an improvement over the feedhorn I already have? It's not too much $$$, so perhaps I could try. Another question - since I am dedicating this satellite to Astra 2D, would there be a feedhorn that would provide the optimum sensitivity for this fringe footprint?

Thanks once again to you all for your input, next weekend I will make some more tests and keep you posted - In the meanwhile I plan to reposition the antenna, and procure the new feedhorn and LNB ( the invacom is not performing very well - but it could be due to the positioning of the antenna, and the incorrect feedhorn).

Bye for now,
T.

 

[Satcom1]

Hello.
Satcom1: Do you think the channel master feedhorn would be an improvement over the feedhorn I already have? It's not too much $$$, so perhaps I could try. Another question - since I am dedicating this satellite to Astra 2D, would there be a feedhorn that would provide the optimum sensitivity for this fringe footprint?

Bye for now,
T.

What you have looks good. I wouldn't spend the money on another lnbf or feedhorn.

Major startup issues for a new dish are;

1- mast is not Plumb and level.
2- elevation and declination are not set right. ****
3- Skew is off.

I notice that your lnbf sits a little high in the holder and you will need to adjust your elevation to get best focus.

The other lnbf you had wired up looks like it should work if you get it in the right focal point. You can side mount that with a bracket and have both lnbf working on different sats. This lnbf has the correct Conical scalar for your dish built in and should work great. If you take the plastic housing off that lnbf it may fit perfectly in the dish arm.


First pic is a lnbf I glued to a P*E feedhorn. (after hacksaw removed conical scalar)
Second picture shows a LNBF with plastic cover removed, neck size is often right size to properly fit your dish arm.

 

[Satcom1]

This conical Scalar does not fit the dish arm lnbf holder. So it is just a guess if it will work right. If you buy anything new consider an Invacom C mount Scalar ring for KU offset dish.

Just wild guess but it looks like LNBF is pushed in to close to dish, and that is critical.

If this dish was from location more then 30 miles away then your elevation must be changed. Did you go to satsig and get you correct Lat and long. and Elevation and Declination?

PS- doesn't look like that original lnbf was sold for this dish. Not important if it works but my Channel Master KU LNBF has a 22 mm throat OD. and fits the disharm lnbf holder good.

 

[akisan]

Hello.
Thanks to all you kind people for your comments, there was a lot to read, and things to chew over, such as the alignment, the feedhorn type etc.,
Satcom1: Do you think the channel master feedhorn would be an improvement over the feedhorn I already have? It's not too much $$$, so perhaps I could try. Another question - since I am dedicating this satellite to Astra 2D, would there be a feedhorn that would provide the optimum sensitivity for this fringe footprint?

Thanks once again to you all for your input, next weekend I will make some more tests and keep you posted - In the meanwhile I plan to reposition the antenna, and procure the new feedhorn and LNB ( the invacom is not performing very well - but it could be due to the positioning of the antenna, and the incorrect feedhorn).

Bye for now,
T.

Hi,
i know it's quite late from ur last post but since i'm facing the same dilemma as u did i thought i may ask u for a hlepful advice.

Could u find any decent fitting Feedhorn-LNB combo that gut u the desired results?

Would be great to hear from u.

I'm trying to catch Nilesat living in western germany

 

[akisan]

Guys i'm still hoping for any kind of help to solve my problem

I've a Andrews Feedhorn with C120 and using it on a NSC 18-1

_http://www.satellitesuperstore.com/images/andrewsfeedinve.gif

With a Gibertini 150cm i can get the Horizontal on nilesat all day long but with this bigger dish only a few horizontal

The signal is much weaker than before

So any helpful advice ?

 

[PaulR]

Hello akisan and welcome to the forum.

Unfortunately tmbp hasn't been back to this site for nearly a year so you may not get a reply from him. This is quite specialised question so you may not get an answer for a while.