Channel Master multi-feed

[Captain Jack]

Finally, the sun stayed out long enough to do stuff outside. One of the things I wanted to try was setting up the multi-feed for my 1.2m CM dish in hope of recreating it.

The goal is to create a multi-feed arrangement for 1w and 5e. These are generally borderline here on anything less than 1m and 1.2m gives 24/7 reception with decent rain margin on both (except SES-5).

The primary focus is 1w, so aligned the dish on that first...



14.5dB - not bad, considering my 1.8m gets 17dB on the same transponder...

5E was 12.5dB (no picture).

After a LOT of faffing, these are the maximum signals I could get in multi-feed setup.

1W (shown as 3E on meter) and 5E respectively...



And here's how it looks.



Err... frankly, I think it's a pretty awful design. The one for Gibertinis is much more solid - this is nothing short of a glorified meccano set. But... it works.

Only a temporary lash-up - as soon as the wife saw it, she shouted "YOU DON'T NEED ANOTHER DISH!". Partially because I am deaf and partially because we already have three dishes around the property...

I can take measurements for anyone interested.

 

[archive10]

Great install!
Is that one of the official CM multifeed arrangements?
Looks very similar. (see part #6067/01)
Probably didn't have much success...

I'm sure @RimaNTSS could knock somthing up in a couple of hours that blew this out of the water (to avoid using the term "trumped this", as the meaning of that term has become questionable lately)...

 

[archive10]

Only a temporary lash-up - as soon as the wife saw it, she shouted "YOU DON'T NEED ANOTHER DISH!".

I had that after two dishes...
You have my full sympathy.
(Now I have four up.... soon five...)
@RimaNTSS must have a special nuptial agreement in place?

 

[Captain Jack]

Is that one of the official CM multifeed arrangements?
Looks very similar. (see part #6067/01)
Probably didn't have much success...

Yep, that's it. Only ever saw it in the PDF you attached until someone happened to have one.

I can imagine it being unsuccessful - it's horrible! The whole elegance of the dish disappears. It's functional, but like you said, Rimant can make a better one. In fact, I think he already has...

 

[RimaNTSS]

I have no personal interest in multifeeds for offset dishes as I think it is waste of it's size. I also remembered that last summer I was experimenting with hardware in the area of focal point of CM 1.2m. Construction became too complicated and I did not like it. So, after couple of days disassembled everything. Only some pictures left.

 

[archive10]

I have no personal interest in multifeeds for offset dishes as I think it is waste of it's size.

Wholeheartedly agree. But for some, it's a matter of keeping the dish count to a manageable number...
I would keep the multi-sat stuff on the multi-focus dishes, and the offset ones to perhaps a single 19.2 or 13E offset duty.
But then not all our fellow sat-enthusiasts can justify an SMW OA-1600 as the multifocus, and some don't have access to proper polar mounts...
So an offset-arrangement might make sense for even a 1.2M dish...

 

[RimaNTSS]

Do not look at my pictures in post #5, they are ugly
@Captain Jack could you please show how the multifeed connects to the bottom feedarm? And also question: Is that possible to install central LNB exactly in the center? Or it is some mm offset?

 

[Captain Jack]

@Captain Jack could you please show how the multifeed connects to the bottom feedarm? And also question: Is that possible to install central LNB exactly in the center? Or it is some mm offset?

I can't remember now but I know that the bottom arm had to be turned back to front. I think I have the manual as well, so will look.

Sadly, the LNB cannot go in the centre, so it will never be as good as original