Mounting 4 LNB's on Channel Master?

dohouch

A few years back, my first steps in Satellite, I bought a 1.2mtr Cannel Master 2nd hand with 3 arm support for LNB.

It was cheap, now I would like to mount 4 LNB's on it. I know it's not ideal but has anybody done this sucessfully?

Photo would be great or even the type of multi-LNB holder used and any mods done.

Don't mention motorising it!!!

Thanks

RimaNTSS

What about self-made? This is not Channel Master, but, I think it is possible to do on any antenna.

dohouch

@RimaNTSS: Thanks for the photo. I like doing self-made also, but so far haven't had the inspiration to come up with anything stable and adjustable. Those clamps on your cross-bar, are they from a chemistry laboratory, or some other place?

This is what I have to work with....

RimaNTSS

Clamps are made from INOX (aluminum one also could be used) square-crosscut pipe, that was cut in about 5cm pieces and then some holes drilled.
On your antenna it is more than possible to attach some horizontal bar on which to put LNBs.
Some another pictures

Greenman

Got these on my trawl for sat pics from where I do not know. Hope they might be of help.:)














:):)

banie01

Greenman wrote: »

Got these on my trawl for sat pics from where I do not know. Hope they might be of help.:)

:):)

Greenman, you can always be relied upon for some great setup pics
If not of your own great setup, 1s like these are always a great staring point for those of us looking to tweak and play!
Thank you

RimaNTSS

Hi! Will bumb this thread as I recently got CM 1,2m. Nice dish. I am not very interested in making multifeed for it, but after I made new LNB holder, so side feedarms become little bit wider and now it is possible to attach couple of LNBs in such a way they will not be hidden behind the feedarms. And one more thing about this dish: I think that original LNB holder (plastic one) does not hold LNB in antenna's focus and not pointing it to the right point on the surface of the dish.

zg3409

I have exact same dish. Old channel masters had a super long feed, and the holder was designed for that, not normal LNBs. The manual for old channel masters is around online and I have a copy too.

There is a guy in Dublin selling old ones, and he also sells the right feed.

With an ordinary LNB in the prime position, it still will not perform as well as the correct feed.

If using an ordinary LNB it would need to be closer to the dish. You can find out easily by holding it in your hand with the TV and receiver beside the dish.

Old channel masters use an non-normal F/d so the beam width of the feed needs to match. Having said that for a multiple LNB setup in non critical situations it will be fine. More modern LNBs are probably more sensitive than an ancient LNB with the correct feed. Have a look at photos online and you can see the massive feedhorn needed, or look at any bookies!

RimaNTSS

@zg3409 thanks for the info. Did you check on your dish whether LNB is located in atntenna's focus and where holder points LNB (if you continue LNB line till it hits dish surface)?

zg3409

RimaNTSS wrote: »

@zg3409 thanks for the info. Did you check on your dish whether LNB is located in atntenna's focus and where holder points LNB (if you continue LNB line till it hits dish surface)?

I have not checked that. I noticed the bottom leg is not held in that well and I modified it with a bolt all the way through.

I am not certain the centre of the LNB should point at the centre of the dish. It would depend on the feed design, distance from the feed to various parts of the dish etc.

caveman99

I have the same Channel Master 1m dish, but in the version that was used by the old Eutelsat internet access 'Tooway'. The difference being the massive aluminium feed pickup and the giant feedhorn without a polarizer. I removed the VSAT LNB Combo and fitted a standard C120 Low Noise LNB. So far so good. Now i want to add multifeed capability but run into problems. The feed support is a bit lower ("between" the side supports, not "above" them as with the plastic LNB holder) and at a slightly different angle. I tried fitting several Multifeed rails i found in my spare parts drawer above and below the supports, but none except the most fragile types fitted the massive feed support block. The Gibertini Rail i was favouring was a total miss. Even with a home made fitting the side support bars are kinda 'in the way' of the additional feed horns. Any idead how i could fit those anyway? Can i go above the tubes without giving away too much gain? I want a secondary LNB to pick up 28 degrees East with the main beam pointing at 19,2 degrees East (situated on the western rim of German, trying to pick up BBC*). Suggestions anyone?

* BBC worked fine here with a 85cm Prime Focus Dish, trying to reduce the dish forest a bit...

RimaNTSS

2caveman99: Why do not you post some pictures of your dish?

snaps

Do you still have signal on 28 east on your 85cm? Depending on how far west you are, you may be out of luck picking up BBC on an offset lnb. The footprint is extremely tight now on uk/ireland.

caveman99

2RimaNTSS: I just signed up, so i can not upload pictures or URL's(yet). From googling around though it's basically this dish and feedhorn clamp:

http:[slash][slash]www[dot]satsig[dot]net[slash]el-molino[slash]tooway-26[dot]jpg

http:[slash][slash]media[dot]cylex-uk[dot]co[dot]uk[slash]companies[slash]1272[slash]3684[slash]images[slash]pic_Amsat-tooway-vsat-dish-_618452_large[dot]jpg

i'll put up some hires images of my acutal dish later, when the board allows me to. :-)

2snaps: I still have a decent signal on my 85cm dish from Astra 2F. Satbeams.com even recommends 65cm for my location:

"Reception details EIRP level = 49 dBW Recommended dish size = 65cm / 25.6in"

And even if the multifeed reception won't work, i'll swivel the dish around and take 19,2 East out of the prime focus. Basically leaves me with the same mechanical problem though, plus aiming for 5 LNB's in total (10E, 13E, 19E, 23.5E and 28.5E), i fear if i move the prime focus to 28.5 i'll have difficulties with the Eutelsats on 13 an 10E.

RimaNTSS

OK, caveman99, has sent me pictures, and I am posting them now. That is nice antenna, even it has name on it "tooway" it is still well known "Channel master 120". And it looks pretty fresh, as new. Those dishes are well known as not good ones to make multifeeds on them, and also that LNB is not located at the very focus of the dish (I want to be wrong about last statement, but, unfortunately, it seems to be true ). The better way how to adjust this dish for multifeed is to make new LNB holder, or even make new feedarms and LNB holder, that is IMHO. I've got 4 such a dishes, so, someday I am going to desighn completely new feedarms and LNB holder, but that can take quiet a time.

snaps

Your best bet might be to motorise it!

RimaNTSS

Motorized and stationary systems, both have pluses and minuses, so combining them could combine pluses and eliminate minuses of those systems.

RimaNTSS

I have 3 LNBs on my Channel Master 1,2m ATM, one of then could be Ka (but I do not have one). Video

explains how it works

zg3409

Receiving 28 East in Germany is possible, HOWEVER, many of the channels are on a narrow beam DESIGNED to give a very weak signal.

Look here:
http://satbeams.com/footprints?beam=5595
and click on some of the SPOT beams. You can see they are intended for UK and Ireland only.

Look here:
http://www.lyngsat.com/Astra-2E-2F-2G.html
and see for example
10714 H tp 41 UK, means it is on the "UK" beam meaning it will have low signal in Germany
12207 V tp 26 Europe Ku, means Sky news would be much stronger in Germany.

I would recommend turning your dish to 28.2 and confirming if even the prime focus LNB can receive the weaker channels on the UK beam.

Note in order to receive every transponder you may need an even larger dish. Some channels are aimed at West Africa.

Is there a particular channel you would like to receive. Most of the BBC's are on the narrow UK beam.

RimaNTSS

Turning of my Channel Master is limited by balcony infrastructure and only signals from satellites 9*E-12,5*W can be received. I am not in Germany and can get whole UK beam on my T90, which is also located on the balcony (it is actually visible behind CM120).

RimaNTSS

Hi! Made this multifeed for CM 1,2m for reception from 4,8*E-13*-19,2*E. Used original side-arms but self-made bottom-feedarm.

RimaNTSS

Here is my new version of LNB-holder for Channel Master dish.

20/20

For those who are interested in buying a channel master dish with the full kit also made by channel master have a look at this advert.

http://www.adverts.ie/satellite/channel-master-1-2m-satellite-dish/11484467

STB.

20/20 wrote: »

For those who are interested in buying a channel master dish with the full kit also made by channel master have a look at this advert.

http://www.adverts.ie/satellite/channel-master-1-2m-satellite-dish/11484467

Dollymount

20/20

Close enough.

zg3409

I have no connection with this guy, but he has loads of channel masters for sale in Dublin. You will need to collect and may need a trailer or van as they are one piece dishes:

http://www.adverts.ie/satellite/channel-master-1-2m-satellite-dish-wth-bracket/1616764

He also has wall brackets etc. I bought one from him a few years ago and it is going strong. In the comments you can see I posted a link to the actual owners manual which explains how to make a concrete base etc.

I will quote it below:

This is the EXACT dish for sale:
http://viasatelital.com/manuales/channel_master/channel-master-type-120.pdf

It is 1.2M. You really need the AZEL bracket and stand off wall mounting bracket, and this is designed for mounting on a 3" pole not a 2" as would be normally used in domestic circumstances. I would recommend you buy the dish, mounting bracket AND a wall bracket with 3" mount, otherwise you will have problems mounting it on say a 2" pole. The mount is designed to go on the very top of a 3" pole. Pay the extra. I am not the seller, just someone who bought one from the seller and is very happy. It is great value for a commercial grade dish.

Note you should also be using the recommended non standard commercial feed horn, although a universal LNB will work to some extent. In case someone does not realise the seller has quite a few for sale.

RimaNTSS

Hi! I am testing new mount for CM 120. It works in USALS mode.
Small video how it goes H-H https://www.youtube.com/watch?v=p3IWbRlhWBA

Greenman

RimaNTSS wrote: »

Hi! I am testing new mount for CM 120. It works in USALS mode.
Small video how it goes H-H https://www.youtube.com/watch?v=p3IWbRlhWBA

Lovely stuff as usual.

RimaNTSS

I've got couple of 120cm CM dishes without feedarms. So, decided to make them. Used 10x1mm INOX tubes and standard pipe-clamps as LNB-holders. I do not think that will be hard to tune this antenna.