[Viewsat] DMS International SG-2100 parts?

johnnynobody

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Here's one of the more recent posts on doing this: ? offset angle Primestar 1.2m
I'll have to read through that thread a few times because it hasn't hit me as to what to do. I wonder if someone could simplify the process with a generic step by step procedure without a bunch of comments. Anyway, wouldn't it be as simple as setting the declination as usual and then adjust the elevation rod to get the right angle to true south? The offset for the GEOSATpro 1.2M is 27.3 degrees - since the prime focus antenna for my area is set about 42 degrees does that mean that I should set the elevation rod to give 14.7 degrees instead of 42? This is a bit confusing when comparing the use with an HH90 which has a latitude adjustment on the motor and then an elevation adjustment on the dish but no declination adjustment.
 

johnnynobody

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johnnynobody IF you have an old polar mount laying around from a 6ft mesh dish, you can fairly easily adapt it to the 1.2m dish. All you have to do, is tilt the TOP of the dish forward, by the same offset angle degrees of the dish. The Geosat Pro 1.2m dish, has a 27.3 degree offset. You do this by using some angle-iron from the mount to the top of the dish, and make them long enough to match this offset.
Why can't I just mount the back of the dish flush with the hub and adjust the elevation rod for the angle that I need instead of tilting the top of the dish forward with angle iron (or whatever)? Or adjust declination to set the offset?
 
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primestar31

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I'll have to read through that thread a few times because it hasn't hit me as to what to do. I wonder if someone could simplify the process with a generic step by step procedure without a bunch of comments. Anyway, wouldn't it be as simple as setting the declination as usual and then adjust the elevation rod to get the right angle to true south? The offset for the GEOSATpro 1.2M is 27.3 degrees - since the prime focus antenna for my area is set about 42 degrees does that mean that I should set the elevation rod to give 14.7 degrees instead of 42? This is a bit confusing when comparing the use with an HH90 which has a latitude adjustment on the motor and then an elevation adjustment on the dish but no declination adjustment.
No, the elevation adjustment on a polar mount can NOT compensate for the needed 27.3 degree offset, IF the polar mount is used with an offset dish.

Declination AND elevation on the polar mount, would be set the same as any prime focus dish for your location. The bottom of the offset dish would be bolted directly to the bottom part of the polar mount "ring" (or whatever connection it has) the TOP of the offset dish would have to be tilted FORWARD 27.3 degrees, and angle iron, or struts of some sort would have to be mounted from the top ring of the polar mount, to the top of the offset dish.

Maybe you can see it here: another channel master polar mount attempt
 

johnnynobody

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No, the elevation adjustment on a polar mount can NOT compensate for the needed 27.3 degree offset, IF the polar mount is used with an offset dish.

Declination AND elevation on the polar mount, would be set the same as any prime focus dish for your location. The bottom of the offset dish would be bolted directly to the bottom part of the polar mount "ring" (or whatever connection it has) the TOP of the offset dish would have to be tilted FORWARD 27.3 degrees, and angle iron, or struts of some sort would have to be mounted from the top ring of the polar mount, to the top of the offset dish.

Maybe you can see it here: another channel master polar mount attempt
I don't see anything that looks like a declination adjustment. It looks like there's something there for the offset and elevation adjustment though.
 

primestar31

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Sorry for my post above, but I just got frustrated in trying to get this across. To me, it seems so simple, I don't mean to seem pissed off.

This pic is from RimaNTSS , with an added red line I painted in there. ADD some sort of metal or "all-thead" to your polar mount and ku dish. Can you see what I'm talking about here? Notice that the ku dish is almost "flat" or tilted facing closer to the ground because of the polar mount retrofit? This is what you need to do, when you mount a KU offset dish to a polar mount. That tilt forward is the offset degrees, which is the mentioned 27.3. You'll have to calculate how many inches that is, depending on your particular chosen polar mount donor.

IMG_20170404_103000 adjusted.jpg
raven18mot8.jpg
 
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johnnynobody

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I'll figure something out. I'm not sure what the difference between declination and offset is but as long as things work to give me decent performance I'll be satisfied. Declination and this offset adjustment both seem to push the dish lower toward the horizon.
 

Magic Static

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I'll figure something out. I'm not sure what the difference between declination and offset is but as long as things work to give me decent performance I'll be satisfied. Declination and this offset adjustment both seem to push the dish lower toward the horizon.
Declination and offset are both part of the same angle. If your declination adjustment could go as far as the offset + declination you wouldn't have to modify the mount, just make adjustments.
 
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johnnynobody

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Isn't there a way to adjust the offset by putting an inclinometer on the center feed support? I kinda recall seeing a video where someone did that with a WS9036 dish.
 

waylew

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Okay,I just looked at the pictures for the Geopro 1.2 at Sat AV.
Once you've pulled all the ribs off the Para,you'll be left with that flat plate.Bolt the GP 1.2 mount to that plate.You can then use the ajustment in the 1.2 mount to add the 27.3 degrees for the offset.In other words,from the plane of the plate of the Para mount,tilt the 1.2 down 27.3 deg from that.
On the Para polar mount,the elevation is set for your 42N location,the declination is a compensation because the Earth isn't exactly round(or something like that).Because the Para is a prime focus dish,the dish is "square" to the mount,the signal comes straight in and reflects up to the feed.An offset dish the signal comes in at a high angle and reflects down to the feed,so you have to add in the offset angle to get the straight in signal to bounce down to the feed.
I think that should work.
 

johnnynobody

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Okay,I just looked at the pictures for the Geopro 1.2 at Sat AV.
Once you've pulled all the ribs off the Para,you'll be left with that flat plate.Bolt the GP 1.2 mount to that plate.You can then use the ajustment in the 1.2 mount to add the 27.3 degrees for the offset.In other words,from the plane of the plate of the Para mount,tilt the 1.2 down 27.3 deg from that.
On the Para polar mount,the elevation is set for your 42N location,the declination is a compensation because the Earth isn't exactly round(or something like that).Because the Para is a prime focus dish,the dish is "square" to the mount,the signal comes straight in and reflects up to the feed.An offset dish the signal comes in at a high angle and reflects down to the feed,so you have to add in the offset angle to get the straight in signal to bounce down to the feed.
I think that should work.
Getting that 1.2 meter mount centered on the hub plate might be a challenge but I'll have to wait for the dish to get here to determine what additional materials I might need. I was considering re-using a part of the rib support for the actuator but I'll cut that down so that it's not sticking way out to where someone will bang into it. I should have all the ribs and ring supports removed by Sunday. It's kinda sad to scrap the Paraclipse.......
 

waylew

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. It's kinda sad to scrap the Paraclipse.......
Especially when aluminum is only getting about 20 cents a pound.
A suitable length of angle iron should work fine for the actuator,drill a couple of holes and attach to the plate.
A square and a Sharpee should make it easy enough to locate where to mount the mount.Likely easier to remove the plate to do the work,just make sure you mark the top of the plate at the top of the arc so you get things oriented correctly.
 

johnnynobody

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Especially when aluminum is only getting about 20 cents a pound.
Yeah. It's too bad that we can't get one-fourth the original cost of the antenna......

A suitable length of angle iron should work fine for the actuator, drill a couple of holes and attach to the plate.
I cut down the rib where the actuator connected to. I'm waiting for the paint to dry right now before installing it and seeing if it'll work out the way I believe it will. I repainted the pole but the wife suggested that I paint everything gold instead of flat black. She wanted it to look more valuable than it really is plus she likes lighter colors. I'd like to repaint the new GeoSat antenna flat black or try my hand at repainting in woodland camo. It probably wouldn't void the warranty but who knows?

A square and a Sharpee should make it easy enough to locate where to mount the mount.Likely easier to remove the plate to do the work,just make sure you mark the top of the plate at the top of the arc so you get things oriented correctly.
If I take the hub plate off I'd have to make sure that I don't lose the declination shims. I looked at buying some shims in case I need to fine tune the declination or replace lost ones but the ones I've seen advertised weren't cheap. Of course, I don't have the rest of the shims that came with the Paraclipse. I might look into a modification to add declination bolt(s) instead of using shims - as long as I don't have to do any welding. The hub plate is black so I guess marking it with chalk might make the job of centering the GeoSat antenna mount onto the Paraclipse mount go easier. It doesn't look like I have to be concerned with orientation of the hub plate on the mount, though, but I'll keep it the same - there are 4 holes that go through the declination bracket and hub plate of the Paraclipse that's used to secure 2 of the rib supports so it shouldn't be much of an issue putting it back the same way I took it off.

After I get the actuator mounting arm put on and the actuator attached, I'm going to see what I can do with adding a lube fitting. It will be a bit more difficult since I'm going to be using the 18" actuator that's been sitting in my garage for 10 years. Anyway, I don't think I can use my drill and tap combo bit without drilling into the screw since the actuator pipe is skinnier (smaller diameter) than the bigger boys. At least I know that the actuator still works but it was a PITA to get the pulse sensor wires attached. The 18" actuator wasn't marked as to how much current it draws but I'm willing to bet that it's a lot less than the bigger ones. Too bad there isn't a part number on the actuator but it does have a Venture marking on it. Anyway, an 18" actuator should work just fine on a 1.2 meter dish? If not, I have a 24". I'd rather keep the 24 " as a spare for the 12 footer.

My 1.2 meter should be here tomorrow. Hopefully, this project will go forward without too many hassles. But, it might be a day or 2 before I get it online since I'll have to round up some friends to get it mounted. Too bad I don't some kind of crane to hoist it into place though.
 

waylew

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Well you'll be busy for awhile.:biggrin
From what I've read here on the site,those 18" Ventures aren't real Ventures,just some China stuff with a Venture label slapped on it.But try it and see how it works.
 

johnnynobody

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Well you'll be busy for awhile.:biggrin
From what I've read here on the site,those 18" Ventures aren't real Ventures,just some China stuff with a Venture label slapped on it.But try it and see how it works.
Looks like I won't be doing this today since the dish hasn't shown up. As for the actuator, I'm not sure of the specs on it since the only marking on it is Venture. It must be 36 VDC since it works on 36V but it is a slow mover (and I haven't installed an antenna yet). I'm not sure how well the actuator will hold up since the tube size is 1.25" instead of the "standard" 2 inch.
 

Titanium

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The 18" model is a cheap rebranded SuperJack. Not sure why they would sell this junk.

I quit selling them several years ago, when the brushes repeatedly and prematurely failed. Would refund the money as it made no sense to ship it to replace.
 

johnnynobody

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The 18" model is a cheap rebranded SuperJack. Not sure why they would sell this junk.

I quit selling them several years ago, when the brushes repeatedly and prematurely failed. Would refund the money as it made no sense to ship it to replace.
I'm going to go ahead and use this one. If it breaks I have a 24" acme screw available.
 

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