Assembling an Invacom C120 LNB and Channel Master feedhorn

Jacobo40 · 3 Weeks Ago

Hi, all:

Since this is my first post I hope I'm in the right section(!) and that my problem (sorry, my "challenge") will be clear to all.

I'm updating my satellite equipment (mainly with a view to getting significant amounts of Astra2D, but hoping for an overall improvement in reception over several satellites). I've already bought an Invacom QDF-031 with a matching Channel Master feedhorn. These will be fitted to a 125cm Gibertini antenna.

Since I'm somewhat technically challenged, I have to rely on installers to put everything together and here is the difficulty. Here in Spain (beyond the larger cities) installers have little experience with this LNB and feedhorn which is touted by many to be a particularly good combination. I've been combing the internet to see if I can a detailed description/photos/videos of how it should be done. So far I haven't had any luck.

Does anyone know where I can find this information?

Thanks in advance for any advice.

**Channel Hopper** · 3 Weeks Ago

Its not so much the feed and LNB, but you have to ensure the feed is matched with the feedhorn

CM feeds are best matched with a CM antenna, or at least one that has the same f/d ratio. From memory this will be one that is 0.6.

**Telia** · 3 Weeks Ago

Gibertini have f/d 0.66

embalse · 3 Weeks Ago

Hi Jacobo40,

It would help to know where you are in Spain as the size of the dish and type varies widely depending on the location.

As Channel Hopper has pointed out, if you are using a QDF-031/CM Feedhorn, you are best off getting a CM dish.

With regards to connecting the Feedhorn. Here are some pics of my mine...

My ChannelMaster 1.2 Madrid. Astra 2D

Make sure the O ring is placed between the QDF-031 and Feedhorn. Only 4 of the screws will align, but thats normal. Make sure it is a tight fit so that no water can enter.

Skew and and Focal Depth will depend on your location.

.

Jacobo40 · 3 Weeks Ago

Thanks for the replies.

It's pretty well-known that Astra 2D is rather tricky to tune adequately outside the UK. I've pretty much tied down what size of antenna will work in my area, thanks to the very useful astra2d.com site and my own experience. A 180cm dish is required in most areas of Spain but there are surprising variations on either side of that mark.

There are other practical considerations: cost and antenna location. The ChannelMaster is a very good dish but rather pricey and anything over 125cm in my apartment building is out of the question.

Many people have successfully mated the LNB+feedhorn set-up I've described to the aluminum Gibertini. My essential quandry is to find installation techies in my town who understand the Invacom/CM set-up.

Or at least to be able to show them some photos/diagrams of how the finished article should look.

Jacobo40 · 3 Weeks Ago

Thanks, embalse, for your comments and pics. Both will be very useful.

I live in Salamanca, with an 80cm Televés dish and a Mot-Sat 3 motor. A 180cm dish here would give me almost all of Astra 2D, 24/7 (a fellow Brit in town has that set-up and those results). As I explained, that size of dish is not feasible where I live, so the 125cm Gibertini is a compromise. It should also give me stronger reception of Astra 2D, Intelsat 10-02, Nilesat, BADR and a couple of others.

Mostly my problem is getting a qualified installer in town who can set up the system for me. Most installers here are only called upon to install Digital+, hence my inquiry about documentation.

As an aside and as an example of how strange (capricious?) Astra 2D can be, in a village 125k due west of Salamanca, at the Portuguese border, and with the same equipment as in the city, I get all of ITV, Channel 4 (and variants) BBC1 (regional) but not BBC2,BBC3, etc. Depending on how things work out in the city I may repeat the operation in the village.

Thanks again.

[QUOTE=embalse;877838]Hi Jacobo40,

Originally Posted by embalse

Hi Jacobo40,

It would help to know where you are in Spain as the size of the dish and type varies widely depending on the location.

As Channel Hopper has pointed out, if you are using a QDF-031/CM Feedhorn, you are best off getting a CM dish.

With regards to connecting the Feedhorn. Here are some pics of my mine...

My ChannelMaster 1.2 Madrid. Astra 2D

Make sure the O ring is placed between the QDF-031 and Feedhorn. Only 4 of the screws will align, but thats normal. Make sure it is a tight fit so that no water can enter.

Skew and and Focal Depth will depend on your location.

.

embalse · 3 Weeks Ago

Originally Posted by Jacobo40

I live in Salamanca, with an 80cm Televés dish ,

I understand your situation and if you want a Gibertini you should get one, but with the Feedhorn Combo you want, a CM 1.2 would be money better spent.
That said my advice is if you cannot find a local who is used to setting up at 28.2. Do some research.
Go to ...
_http://www.dishpointer.com/
This will give you the ....
Elevation:
Azimuth (true):
Azimuth (magn.):
LNB Skew
....for your location.

Then just get the local firm who normally sets up Canal plus.

Stand over them as they adjust the dish and give them the above info.

Then ask them to fine tune the LNB on these two transponders.

11778V. 27500 2/3
10891H. 22000 5/6

If they can do that you have Astra 2D.

***Huevos*** · 3 Weeks Ago

Originally Posted by Jacobo40

the 125cm Gibertini is a compromise

Forget the CM feedhorn Invacom quad combination and get yourself a Black Ultra. For more info read this.

Also, if you are getting the Gibertini forget that diseqc motor. With that dish you would a polar mount, actuator and v-box. It's a big dish and has a mast clamp for a 100mm pole. Hanging it on the 50mm motor stub of a diseqc motor would be madness.

Jacobo40 · 3 Weeks Ago

Thanks again for your advice. I like the idea of being proactive and I will get the details from dishpointer and make sure the installer sees them.

Thanks too to Huevos for his cautionary note.

I'll report back on how the installation and results turn out.

Originally Posted by embalse

I understand your situation and if you want a Gibertini you should get one, but with the Feedhorn Combo you want, a CM 1.2 would be money better spent.
That said my advice is if you cannot find a local who is used to setting up at 28.2. Do some research.
Go to ...
_http://www.dishpointer.com/
This will give you the ....
Elevation:
Azimuth (true):
Azimuth (magn.):
LNB Skew
....for your location.

Then just get the local firm who normally sets up Canal plus.

Stand over them as they adjust the dish and give them the above info.

Then ask them to fine tune the LNB on these two transponders.

11778V. 27500 2/3
10891H. 22000 5/6

If they can do that you have Astra 2D.

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Assembling an Invacom C120 LNB and Channel Master feedhorn Information exchange on LNBs, Single satellite, motorised and multi-satellite systems. DiSEqC switches, positioners, motors, actuators, dish-alignment etc.