Questions about reviving long-unused C-band dish

[intuity]

I hope someone can give me some direction here - I spent a while searching the forums before posting, but my searches return way, way, way too many posts or none at all, so either I'm in the dark or dead in the water... Help!

I was recently asked by a friend to remove a BUD from his backyard that was left by the previous homeowners. It's a 12' fiberglass multi-segment dish with a center-mounted LNB/feedhorn assembly, that is on a ridiculously huge articulating mount with actuator arm. The LNB and feedhorn assembly that is mounted on it right now is a Chaparral, and as it has its own pair of wires, I assume it has the ability to change polarization ("co-rotor", I believe?) as well as the actuator arm has several wires - the whole bundle goes into the ground to someplace unknown.

The dish itself is in okay condition, it's multi-sectioned fiberglass panels,and after undoing each section's bolts, I was able to take it down fairly easily without breaking anything - but the bolts were an absolute pain in the butt. Why each panel requires 16 frigging bolts is beyond me, other than supporting against wind shear. I had to remove the actuator arm from the mount to manipulate the mount to accessible angles, but it should reattach just fine.

Questions, though. With it being fiberglass, I was not expecting it to have a non-smooth surface. Each panel has a fine dimple pattern on the face. I plan to power-wash the panels before re-mounting the dish, as they are absolutely filthy with algae, dirt, et cetera. Do I need to be careful that the power-washing does not destroy this surface's finish?

I should have no problems re-aligning the mount, as it's only moving roughly 40 or so miles north, so the azimuth should remain relatively the same I expect. Just point the center of the dish due south, and move the actuator all the way west to maximum then back east to maximum, set the limits, and voila - yes?

I'm pretty sure that the actuator just pulses back the output from a rotary encoder, and is completely dumb, e.g., non-DiSeqC. Unfortunately, what I can find in the way of "modern" receivers (e.g, DVB-S2, MPEG-2/4, BISS support, etc) seem to all lack the expected 5-wire polarotor connections in lieu of DiSeqC signal/22 khz support... Options? External rotator? Pass-through from my Chaparral 90 to a new FTA box? Arduino? Open to suggestions here.

I have a great interest in sky-scanning, not just for wildfeeds or unpublished transponder/channel information, but eventually I will be adding transmitting to this earth station for EME/scatter contact fun. I saw a video on Youtube by a guy who used a Dreambox, with custom Python scripting, to assist in this sort of thing, and it piqued my interest considerably. Comments? Dreambox vs. DVB-S2 PCI/PCI-e card?

Regarding the actuator assembly, if indeed it does what I think it does with the rotary encoder pulshing, is it standard or manufacturer specific ? If it's standard, I should be able to convince an Arduino board to shack up cozy with some relays and a bit of code to do what I want. Opinions?

Hopefully someone can point me in the right direction - thank you in advance If I find anything interesting, I'll be glad to share it in the right forum, the one that isn't Google-indexed.

-- Jake

 

[Magic Static]

to the forum Jake. Sounds like you have found a great dish to restore! This is a good place to post about it too. We all like pictures, so post lots of those too.
The dish's reflective surface is a wire mesh in the fiberglass. Don't be afraid to scrub it clean. Sounds like you have a Co-rotor feed horn with both a C-Band LNB and a KU band LNB. Very nice
Modern receivers do not have dish control systems built in. They do use DiSEqC to communicate with DiSEqC devices, switches and motor controllers. There also are no connections to control a polar-rotor motor in an old style feed horn.
There is one dish controller that can do it all and that is the Titanium ASC1. No others have polar-rotor control. But there are plans for simple electrical circuits you can build to control a polar-rotor motor. I have built a few of those An Arduino may be a little bit of overkill for the project
I started my satellite hobby with a PCI DVB receiver. Big learning curve there

The dish actuator has gone through quite an evolution. new actuators use a magnet wheel and reed switch for a position sensor. Old school actuators started with potentiometers for sensors. Later replaced with optical switches or hall effect switches. There is an adapter for the ASC1 that allows you to connect optical and hall effect switches.

 

[intuity]

Thank you for the welcome - I look forward to being a contributing member and supporter While I would love to say that the LNBF assembly does C-band and Ku-band, it does not, it is C-band only. I probably should mention that this entire setup has been unused for at least 18 years, as it was there when my buddy bought the house that long ago, and I found markings on the back of one of the panels that I think are alignment marks scratched into it by the people who installed it, along with what looks like a signature and a date that appears to be May 8th 1989. My friend said that was a year after the house was built, so the dish (and probably the LNBF as well) probably dates from at least the late 80's.

The LNBF seems to be in good shape, even if it's a bit weathered. The plastic cap on the feedhorn and the rear of the assembly are both badly weathered and chalky, and I am trying to not handle those plastic parts as much as possible because it seems they are disintegrating with every touch.

Should I look into replacing the LNBF assembly before I get into this? Certainly couldn't hurt to modernize the whole thing, but I really don't want to start chucking money at this project until I can at least verify my installation efforts are going to be successful.

If I do decide to modernize, I understand that I would be looking at a new LNBF that will do C and Ku-band and a new actuator assembly at the least - and probably a DiSeqC switch and actuator controller. It's surprising to me, but understandable the amount of influence that DSS technology has had on the direction the entire industry has been moving toward,and I wonder what's next...

 

[Titanium]

Jake!

Age shouldn't matter as long as the dish has not warped and it is mechanically sound. The actuator should be cleaned and the arm/gears lubricated before applying any power. Connect a 18v drill battery or a 12Vdc car/ATV battery to the two motor wires in the motor housing to slowly move the jack. Reverse the leads to reverse the direction of travel. Legacy actuators rarely fail, but often the brushes are worn or the reed switch will fail after long-term storage, but these are usually cheap and easy to replace.

It would be easier and more simple to learn the system operation to first buy a C-band LNBF to install and align the dish. Once you have some experience with operating the system, install the servo feedhorn and consider upgrading older LNBFs if they are failing. LNBFs are easier to install and use, but a properly installed servo feedhorn will provide the ability to optimize reception for each satellite and transponder.

We look forward to assisting with your project and welcome to an addictive hobby!

 

[intuity]

I managed to get a few pictures, so here goes...

This is the dish, on its mount - half-way disassembled. The brush and grass around it was waist-high, but nothing that I couldn't tackle, armed with a razor-sharp cutlass and sheer determination

From what I can find, this appears to be a pretty decent assembly, complete with feedhorn, LNB, and polarotor ...?

 

[Magic Static]

Very nice! Now all you need is to enter and win the contest in this forum for a new Titanium Satellite ASC1 dish controller.