Motorized Dish 500

[Machman]

My motorized Primestar is on a tripod, and thus can only be on the flat part of my roof from where I can only see 93W - 129W. The slanted part of my roof has a place that can see as far east as 77W if not more, but there's no easy way to mount another decent-sized dish there and I don't have another good dish anyway. I just happened to have a spare 6-block non-penetrating mount, a Sadoun DG240 motor, and a Dish 500 laying about, so I decided to put them to good use. I'd say more, but I'll just let the pictures do most of the talking. No booze was involved in this project, I swear!

The skew adjustment plate in the back of the dish was running into the motor shaft when I tried to raise the dish to the necessary elevation setting, so I had to cut a notch out of it with a Dremel.

119W is about half a degree off my true south and the LNB isn't at boresight, so I did some calculations and turned the motor shaft a few degrees to compensate. I realigned the motor with the compass, hooked up the 110W LNB, peaked the signal, turned on the receiver, and suddenly found myself watching TV on the roof!

Once I'm sure that this thing is tracking the arc properly, I'm going to put a linear LNB on there and see what I can get. If nothing else, I'm getting one more channel than before, so I'm declaring this project a success

Edit: In case anyone is curious, that channel is NBA TV which is currently in the clear at 110W (MPEG-2) and 72.5W (MPEG-4).

 

[Machman]

Replacing the circular LNB with a linear ended up being more difficult that I expected. I made a bracket out of two conduit hangers and a strip of steel, and bolted it into the 'D' shaped plastic socket that held the circular LNB. The whole thing wobbled about and was just too flimsy to work reliably.

So, rather than replace the LNB, I decided to make a bracket to attach the linear LNB to the side of it. The parts stack up as follows:

Nut
Steel tape
Lockwasher
Nut
#3 conduit hanger
Lockwasher
Carriage bolt

The end result is very solid. I'm going to hook it up this afternoon and see what I can get.

 

[satcom1]

Machman-

Really nice....you get four AttaBoys.

keep us informed of progress!

 

[Machman]

Thanks satcom1

I finally got the linear LNB up and running tonight. I set the receiver to "PASTOR SCOTT" on Galaxy-25 and turned the motor by its switches until the quality went above zero. I was able to get the quality to 15 with a little fine tuning of the motor, and got a few additional percent by angling the LNB inward a bit more. Whenever the quality hit 20 I would get a few corrupt frames but nothing more. I tried tweaking the skew but got no improvement.

I didn't have much hope until I tried a few other transponders... holy smokes! Nearly all of the other vertical TPs came through at 30 percent or more! Some of the weaker ones had occasional corrupted frames but were watchable. A few like 12177V were in the 35-45 range and rock solid. I left it on Fashion TV for a few minutes and saw no errors (but saw some stuff that made me wish I had watched that channel before ).

I tried the horizontal TPs but they all had zero quality. A horizontal blind scan found a few TPs but no channels. I would have investigated further but my battery was too low for me to continue. I have no clue what the problem might have been.

I never would have believed that this could possibly work until I saw it for myself. I think the results are comparable to the 1m mini-BUD results that others have gotten; it's totally worth doing if putting up a larger dish is impractical, or if you need a small dish that you can hide from your landlord (or wife, for Fashion TV ). Installing and aligning these little dishes is easy (assuming you don't motorize it), and you can find them for free on trash day occasionally.

 

[Anole]

There are some good LNB bracket ideas in this thread, but lots of folks have posted neat pictures with many great ideas in past years.

In the thread above, if you take the links, you'll see where I used a Phase III dish and linear LNB.
That conduit-hanger bracket was secure.

The best one for the Dish 500 that I've ever seen was by McGuyver.
However, I can't find the thread where he posted it.
(see below)