Motorizing a Channel Master 1.2m

[BrettTRay]

I'm new to this FTA stuff and would like to know if there is anyway to motorize a channel master 1.2m dish. will the pole mount on the back of the dish be to big to fit on a motorized mast. I had this dish give to me and would like to be able to use it instead of having to buy one. It came with a Norsat PLL 1000A LNB but would like to get one of the Invacom .3 lnbs someday

 

[PSB]

Possibly, the SG2100 motor can handle dish up to 1.2m but if its too heavy it may not be a good idea. The SG2100 has an upgraded mounting tube at 50mm in diameter, so it may be an easy job. At worst some PVC pipe could be used to make up any difference in diameter needed for mounting.

http://www.dmsiusa.com/sg2100.htm

And check here for other options and ideas.

http://www.sadoun.com/Sat/Order/Motors.htm

 

[Tron]

The problem is the 1.2M Channel Master is a very heavy dish compared to, say, the 1.2M Fortec. I have the 1M version of your dish fixed-mounted on a non-penetrating roof mount and pulling in G-10R. For my motorized dish, I use a Winegard 76CM....

 

[Stefan]

http://www.satelliteguys.us/showthread.php?t=66273

http://www.satelliteguys.us/showthread.php?t=42450

See the above links for some ideas on how to mount your dish to motor. In those threads you see at least 2 different approaches to mounting a 40 x 30 primestar/channel master dish to an SG2100. I believe the channel master 1.0 and 1.2M dishes use a similar (but much heavier and with a different bolt pattern) mount to that used on the oval primestar dishes. I've seen pics of 1.0 and 1.2M Channel master dishes using similar mounting techniques to the way I mounted my 40 x 30 oval dish with the only diffence being that instead of PVC pipe, adapter rings cut from composite decking material were used. I believe it was Spyder who did something like that. So, you might want to search for posts made by him describing the exact process. Anyway, on the 1.0 and 1.2M dishes the mount is indeed much heavier than the smaller one used on the oval primestar dishes. So, your best choice might be to consider something like Ziploc shows in the thread I linked to above. A mount like his would likely be much lighter and thus easier on your motor.

As for LNBs, not to say anything bad about the Invacom LNBs as they are good LNBs, but a Norsat PLL LNB is probably a pretty good LNB. Norsat is a very good LNB manufacturer and often times a Norsat LNB rated at a higher noise figure will actually outperform LNBs from other manufacturers with better "on paper" performance ratings or at least that's been my expereince. So, your Norsat LNB is probably a decent performer. The downside is it's likely a WR-75 LNB. These type LNBs generally mount to a rectangular wr-75 flange and do not have voltage controlled polarity switching. They only recieve one polarity at a time and this polarity is determined by either a polarising filter between the LNB and feedhorn and it's orientation, a polar servo that rotates a probe inside the feedhorn and directs the signal from that probe to the LNB, or a special dual polarity feedhorn which is shaped like a tee and has flanges for 2 LNBs and directs and filters each polarity to one of each of the LNBs. So, to make your LNB capable of recieveing either polarity youd need either a polar servo or dual polarity feed. With the dual polarity feed youd also need a second WR-75 LNB and a switch to switch between the 2 whenever you wanted to switch polarity. With the polar servo youd need a reciever capable of controlling a servo motor. The pansat 2500 can do this. I asssume the 2700 probably can also but I can't guarantee this as I don't own a 2700. Youd also need to run extra wires form your reciever to the servo motor. So, while the Norsat LNB is probably pretty good, it'll be a little bit more work and require purchasing a few additional parts to make it practical for recieving both polarities.

 

[Mr Tony]

The SG2100 has an upgraded mounting tube at 50mm in diameter, so it may be an easy job.

Pete
The 50mm tube will handle up to 2 inches. Most larger dishes (like my DirecPC and probably this one) are 2 3/8"

 

[iammike]

At worst some PVC pipe could be used to make up any difference in diameter needed for mounting.

I did this with a Primestar dish and an sg-2100 over the weekend. It works pretty well, but you will probably want to drill a hole in the PVC, and your dish's mount if necessary, so that you can bolt the whole assembly to your motor. I found that no matter how tight I clamped down the Primestar mount, it was still able to move a little on the PVC. When I cinched up the bolt really tight, and I do mean real tight, it took the play out of the dish. I suspect you'll run into a similar issue with the 1.2M dish.

 

[PSB]

Make sure to SPLIT the PVC tube length ways all the way down, it should help when tightening it up!

 

[iammike]

Make sure to SPLIT the PVC tube length ways all the way down, it should help when tightening it up!

I cut half inch or so splits in both pieces, but all that weight can generate a pretty fair bit of torque. It didn't move much, if I didn't have pencil marks lining up the motor and the PVC I probably wouldn't have even noticed. Problem is that a small movement there translates into a big movement on the dish. I was also paranoid about something getting loose some day and the whole works making a loud crashing noise in the middle of the night.

 

[Stefan]

One more thing about adapting the primestar mounts (on the smaller oval dishes) to the SG2100 with PVC pipe, is that it helps to cut some material off of the ridge on the part of the mount where the bolts tigthen up and clamp together. If you look at that part you'll note there is a ridge that butts up against the opposite side whenever the bolts are fully tightened. This was probably put there to limit the how much you could tighten up the bolts and limit the amount of clamping force the mount could apply to the 2 3/8" pole it was original intended to be used with. They probably didn't want you to over tighten the bolts and either crush or deform the pole. Anyway, when used attach to the SG2100 motor shaft using the 2 pieces of shedule 40 PVC, this ridge, or at least a portion of it needs to be cut down. I used a dremel. When you do this you'll be able to tighten it further and apply more clamping force.

 

[sharris]

The channelmaster is too heavy....approx 20lbs over what the sg2100 is rated for. I know, as I looked into this as well. Some folks I have heard use a c band actuator and hook it upto an independent sat dish mover. I am affraid the only use for a 1.2 channelmaster is stationary unless you want the hastle of a c band actuator etc..

 

[Stefan]

It may be a bit over the rating of the motor, but I've seen people mount 1.0M and 1.2M channel master dishes on these motors before and it seems to work. How it affects long term reliability, I don't know. I guess that would depend on how much and often you move the dish around. Constantly switching back and forth between channels at the extreme ends of the arc might perhaps result in reduced reliability. Also how windy it is at your location might be a factor. I have my 40 x 30 Primestar located behind a structure to help block the wind off of it. I have it mounted high enough it "sees" over the top of the structure but low enough that the structure blocks alot of the force of the wind. Anyway, if it were me I'd try it. I'd try to make the mount as light as possible and I'd try to place the dish in a location it wouldn't recieve alot wind loading. Also, I'd be careful about not constantly moving the dish back and forth alot and I'd try to always wait until the dish had come to a stop before moving again back in the other direction.

 

[raydio]

As my daddy used to say - "no balls, no blue chips!" I am thinking of doing the same to my new Patriot 1.2 after it arrives. However, I am thinking of the Stab HH120 as it has the upright post on it. I think it is more conducive to working properly with the larger dishes. I think the Patriot is a bit lighter that the channel master as well. The Stab can take 37.5 lbs max.

 

[mchomicz]

Stab actually makes 76mm adapter rings intended specifically to be used with Channel Master dishes (on stab HH120). Why come up with some half-baked solution using split PVC tubing if a real product actually exits?

Yes, it can be done. But unless you are real good with "tinkering" up contraptions like this - it's virtually guaranteed that you'll get better results with a Stab HH120 (incidentally - available from our sponsor - SADOUN) and 76mm adapter rings. Not to mention that it's way easier to slide a heavy Channel Master dish on TOP of the HH120 than to suspend it from UNDERNEATH an SG2100

I am thinking of the Stab HH120 as it has the upright post on it. I think it is more conducive to working properly with the larger dishes.

I think Stab HH120 is the ONLY way to go. Yes, people have done it with SG2100. I have tried. It's difficult. And my dish is neither 1.2 m nor as heavy as a Channel Master 1.2m (using a 1m Winegard). I actually had the dish mounted at some point but decided to take it down and put a 76 cm Winegard on the SG2100. It's actually a pretty easy operation with a 76 cm dish and a much harder one with a significantly heavier 1m Winegard. I'm sure there are lighter 1m or 1.2m dishes out there that would work better on SG2100. But I know form personal experience that putting a 1m Winegard on an SG2100 is a chore and it sounds like 1.2m Channel Master is both heavier and has a bigger diameter mount (thus requiring more PVC filler).

Just an opinion. I've tired it and did not like the results. I know for a fact others were successful though.

Michael

 

[Stefan]

I agree the PVC pipe method is probably not the best method for the 1.0m and 1.2m channel master dishes. In fact, I believe I've stated this before. I don't have a 1.2m but I do have a 1.0m and while the 1.0m mount attaches to the same size pole, it's much heavier, made of thicker less flexible metal, and made a bit different that the mounts used on the smaller oval dishes. Therefore, I completely concur that the PVC pipe method is probably the less desireable method with these dishes. I still like the PVC pipe method better for the smaller oval 40 x 30 dishes though as it's easy and makes for easy declination adjustment.

Also the Stab motors may indeed be a much better choice for these dishes. The reason I choose the SG2100 for my 40 x 30 oval was I thought it would be sufficent for this dish, it was cheaper, and I've heard it has a wider range of travel. Also if there are ready made adapter rings then I'd say definitely go with that. When I made my mount I hadn't seen any such adapters. So, I had to come up with something on my own.