Orbitron SX-10 Dish

Houston Rockets

SatelliteGuys Pro
Original poster
Aug 6, 2021
202
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Dallas Texas
Hello a while back a member (brex2001) had posted a picture of the scale for a Orbitron SX-10 Dish
I redid it today hopefully this will help anyone who has this dish and the scale is no longer on it...

 

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I did Orbitron 10' starting pre-1990 and 8.5' post-1991. Liked their design concept, clean looking. Also very compact in pre-assembled form. Based in Spring Green, Wis. and said to be designed by protege of FLW. Ribs were slid onto tabs on a central assembly plate, perimeter sections were bolted to ends of ribs and spliced to each other, and then the ribs were compressed between 2 center plates to form the structure. Something like 18 bare mesh panels were then placed between each of the ribs and secured with a locking strip. This was when almost all else was the 4-section stuff. Downside was that with enough force panels could be pushed out. Also they had a .3 f/d and rejected TI better.

The mount was equally unique with its "spin" declination setting. "Spinclination". How are there any of these still around?
 
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Funny, tonight I flipped to an old episode of Strange Evidence and saw an original 10-footer with the bare aluminum ribs (I always thought they looked better- cooler? than when they started painting them black along with all else) in footage from 1994.

Now I'm remembering that I had started making some mods to the polar axis pivot bolts because some were loosening in use. It had like 2 separate bolts top & bottom instead of a single long throughbolt. I think I was getting longer ones and double-nutting them. Did a lot of funky mechanical hacks back then. Also painted the black feed covers silver to reject heat, then later decided against feed covers altogether, just seal coax at the LNB.
 
Funny, tonight I flipped to an old episode of Strange Evidence and saw an original 10-footer with the bare aluminum ribs (I always thought they looked better- cooler? than when they started painting them black along with all else) in footage from 1994.

Now I'm remembering that I had started making some mods to the polar axis pivot bolts because some were loosening in use. It had like 2 separate bolts top & bottom instead of a single long throughbolt. I think I was getting longer ones and double-nutting them. Did a lot of funky mechanical hacks back then. Also painted the black feed covers silver to reject heat, then later decided against feed covers altogether, just seal coax at the LNB.
Speaking of hacks to them, I took the elevation bolt and cut it off,and put a 18” actuator to control the elevation on weak TP’s on far east or far west satellites able to pull any weak TP using that method.
 
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I did Orbitron 10' starting pre-1990 and 8.5' post-1991. Liked their design concept, clean looking. Also very compact in pre-assembled form. Based in Spring Green, Wis. and said to be designed by protege of FLW. Ribs were slid onto tabs on a central assembly plate, perimeter sections were bolted to ends of ribs and spliced to each other, and then the ribs were compressed between 2 center plates to form the structure. Something like 18 bare mesh panels were then placed between each of the ribs and secured with a locking strip. This was when almost all else was the 4-section stuff. Downside was that with enough force panels could be pushed out. Also they had a .3 f/d and rejected TI better.

The mount was equally unique with its "spin" declination setting. "Spinclination". How are there any of these still around?
I guess you didn’t understand what I was saying, I took the picture that was posted a while back and used photoshop to restore it, then printed it out and going to laminate back on the dish.
 
I think I got it- the dish structure centers on a hub that has a ~4" round pipe stub to insert into the ~4 1/4" round mount opening. The pipe stub on the dish is cut at a specific angle before it's welded to the center hub, thus when inserted into the mount receptacle the dish structure is free to "spin" on the mount, with a continuous up/down wobble. Wherever it's specifically stopped on the "spin" and the 2 set bolts in the mount receptacle tightened, that's the declination setting, and the mount receptacle (when new) had a declination scale with degree markings attached in form of an adhesive strip. The dish hub had a little white line in paint (maybe also an impression mark) to align to indicated latitude spec on the sticker. So the mount sticker would weather away and maybe also the hub marking, and if you need to reset declination what to do? For my part as I recall, I simply did a spin-around on the dish, observing the up & down change, guessed a spot basically in the middle, locked the set bolts and tried the arc. Peaking elevation straight south, I would start moving west. If getting noticably weaker signal, I'd check to see which way elevation would strengthen it, and then I'd know where to go back and adjust on declination. I'd be sure to leave the elevation where I had first set it, go back straight south, adjust the declination (loosen set bolts, slightly "spin" dish) to put the dish either slightly higher or lower according to what the more western arc needed, re-peak elevation (straight south) and then retry the arc.

Another facet of the dish's ability to "spin" on the mount was that it facilitated installation of the panel sections and retaining strips. Those would go in after the dish structure was fully assembled, the hub bolts tightened to rigidize it and the finished structure hoisted up into the mount. Also not having the panels in yet made for easy work to grab it by the ribs and perimeter to land the center stub pipe into the mount. Then just spin and put in panels. Easy 1-man job, and I was a 1-man band.
 
I think I got it- the dish structure centers on a hub that has a ~4" round pipe stub to insert into the ~4 1/4" round mount opening. The pipe stub on the dish is cut at a specific angle before it's welded to the center hub, thus when inserted into the mount receptacle the dish structure is free to "spin" on the mount, with a continuous up/down wobble. Wherever it's specifically stopped on the "spin" and the 2 set bolts in the mount receptacle tightened, that's the declination setting, and the mount receptacle (when new) had a declination scale with degree markings attached in form of an adhesive strip. The dish hub had a little white line in paint (maybe also an impression mark) to align to indicated latitude spec on the sticker. So the mount sticker would weather away and maybe also the hub marking, and if you need to reset declination what to do? For my part as I recall, I simply did a spin-around on the dish, observing the up & down change, guessed a spot basically in the middle, locked the set bolts and tried the arc. Peaking elevation straight south, I would start moving west. If getting noticably weaker signal, I'd check to see which way elevation would strengthen it, and then I'd know where to go back and adjust on declination. I'd be sure to leave the elevation where I had first set it, go back straight south, adjust the declination (loosen set bolts, slightly "spin" dish) to put the dish either slightly higher or lower according to what the more western arc needed, re-peak elevation (straight south) and then retry the arc.

Another facet of the dish's ability to "spin" on the mount was that it facilitated installation of the panel sections and retaining strips. Those would go in after the dish structure was fully assembled, the hub bolts tightened to rigidize it and the finished structure hoisted up into the mount. Also not having the panels in yet made for easy work to grab it by the ribs and perimeter to land the center stub pipe into the mount. Then just spin and put in panels. Easy 1-man job, and I was a 1-man band.
I worked for Frank Leach from 1991 to 1999, as Technical Director at Orbitron. He came to Wisconsin to study under Frank Lloyd Wright, and stayed in the Spring Green area for many years, retiring when the business was sold in 1999.
Sometime in the early 1990s I remember an episode of Northern Exposure, where they got a satellite dish at the bar.
Marilyn said that it was a "Zorbitron" brand antenna. My recollection was that it was fiberglass in construction, but that scripted comment was some good inside humor for those of us in the satellite industry.
 
As I recall with the intro of the 8.5' the panel placement was changed such that they then needed to insert into grooves at the edges of the ribs rather than lying flat on top of ribs to be secured by locking strip. Maybe looked good on paper (fewer parts), but this was a real pain- you had to align both edges of the panel simultaneously to each rib it was going into while also gripping it on both sides to apply force toward the dish center to wedge it fully into the rib grooves. Sometimes it worked OK, and others, not really. Unforgiving as to any dimensional variations rib-to-rib or in panel cut. Sometimes ended up with distorted, "cupped" panels. Also I believe that's when started using a rubber "gripper" molding around perimeter to secure the panels there, which was unneeded on the previous design on which panels were "started" by inserting into grooved perimeter rather than into grooved ribs. Not good from a lifespan perspective; collected dirt.

All in all, I liked the original design, didn't see any of the running changes (both to the 10 and with the 8.5) as beneficial (including those pivot bolts), and indeed saw most of them as negatives.
 
As I recall with the intro of the 8.5' the panel placement was changed such that they then needed to insert into grooves at the edges of the ribs rather than lying flat on top of ribs to be secured by locking strip. Maybe looked good on paper (fewer parts), but this was a real pain- you had to align both edges of the panel simultaneously to each rib it was going into while also gripping it on both sides to apply force toward the dish center to wedge it fully into the rib grooves. Sometimes it worked OK, and others, not really. Unforgiving as to any dimensional variations rib-to-rib or in panel cut. Sometimes ended up with distorted, "cupped" panels. Also I believe that's when started using a rubber "gripper" molding around perimeter to secure the panels there, which was unneeded on the previous design on which panels were "started" by inserting into grooved perimeter rather than into grooved ribs. Not good from a lifespan perspective; collected dirt.

All in all, I liked the original design, didn't see any of the running changes (both to the 10 and with the 8.5) as beneficial (including those pivot bolts), and indeed saw most of them as negatives.
The Orbitron C-10 was of the type that used a locking strip that pounded in between each panel. I never did like that model, because it had issues in high wind areas and simply did not hold completely in place. The SX-10 was similar to the SX-8.5 in that you had to slide in the panels as described above. With only 12 panels, the SX-8.5 would have been less parabolic than the SX-10 (18 panels) because the panels were wider on the 8.5. Orbitron had a special custom forming machine that put a compound curve into each panel. This was refined even more with the advent of Micromesh, a tighter pattern with smaller holes. Mesh panels were rolled up and wrapped in plastic, and shipped in a single box that was even reasonable to ship with the Post Office. When these specially formed panels (Micromesh version) were unrolled, and installed carefully by sliding into the grooves on each side of that segment, they were noticably better in performance than a normal flat panel. Next step was to tap mesh clips into the back of each panel, which could normally be done with your fingers. Then the edge trim was installed on the perimeter, finishing a very stable knockdown type reflector.
After installing one or two antennas, those that installed for a living usually got the "feel" of how to slide mesh into each pair of ribs, and it was not a terribly difficult process. I installed antennas in many remote areas during my career, and you simply could not pack a sectional antenna in pieces inside a small bush plane to do a consumer installation. Orbitron and Paraclipse had it figured out on how to cost-effectively get their products delivered almost anywhere.
The Orbitron SX 8.5 and SX 10 were very popular models for export, with the 8.5 foot model fitting 416 antennas in a 40-foot container. That was about three times more antennas than a pre-assembled quarter panel sectional type in a similar diameter. Orbitron's knockdown antennas had this shipping advantage for packaging, and I noted that they outperformed sectional antennas when tested side-by-side. It's too bad the industry vanished in the early part of the 2000 decade.
 
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