need to improve pointing accuracy

[ZetaMale]

Noise in the pulse counter wiring would be my first guess? Please describe the wiring to the actuator, what type of actuator, wire gauges, shielding, grounding etc... I'm sure there are smarter ones than me here that can also help get to the bottom of this situation. Electrical noise would make some counts get lost on the way back to the position you are going for, then the dish would be in wrong spot. Motor and sensor wires in the same bundle is the cause I have seen here mostly.

I'm using the standard "ribbon" cable. By that, I mean there's 2 coax runs, and motor wire bundle and a polarator bundle. The actuator pulse counter is in the same bundle as the motor power wiring. The polarator wiring isn't used because I'm using LNBF's. As for grounding, all my outside stuff is single point grounded to the power company ground rod. I've tried attaching the motor wire bundle shield to a ground terminal at both ends, then just one end, and then no connection at either end - doesn't fix my problem. A different make/model actuator has been tried also. I've even tried using decoupling capacitors. I had this same problem on both my old Paraclipse 12 footer and my newer KTI 12 footer also. One would think that the count wouldn't be so far off that the signal would be lost. The count is off by 2-5 counts (9% to 22.5%). The pulse count averages to 22.17 counts per degree for the KTI using a Gbox. One thing I haven't tried is using the polarator wiring for the actuator pulse count. But, being the pessimist that I am, I don't expect that to fix my problem either.

 

[primestar31]

When is the last time you confirmed that your ground wire for the wire bundle, is truly grounded to the power company rod in the ground? Could it have disconnected? It should be simple to check this with an ohmmeter.

If it really is connected, dump 4-5 pails of water on the ground at the rod. Let it soak in a bit, and see if the count is still off.

 

[fred555]

The actuator pulse counter is in the same bundle as the motor power wiring.

This is a concern. Do the pulse counter wires have their own shielding jacket, separate from the motor wires?

 

[Magic Static]

This is a concern. Do the pulse counter wires have their own shielding jacket, separate from the motor wires?

That is the way my ribbon is made. the motor and sensor wires in one bundle but the sensor wires are shielded and there is a shield drain wire with the three sensor wires also.
IMHO, I would lose the GBox

 

[fred555]

That is the way my ribbon is made. the motor and sensor wires in one bundle but the sensor wires are shielded and there is a shield drain wire with the three sensor wires also.
IMHO, I would lose the GBox

Gotcha, I should probably pay more attention. Swapping an lnbf and posting at the same time.

 

[Titanium]

I would try switching the sensor wires to the other bundle (servo) and connect the shield for the bundle only inside to the structure ground.

Is the dish grounded? Is the dish bonded to the structure ground? If not, there may be voltage potential and this may be causing count errors.

Disconnect all wires including coax wires connecting to the dish. One by one, measure the voltage between the structure ground (outlet in the room) and each wire, shield coax stinger/ braid. If any voltage is higher than 0.5v, there is an excessive voltage potential and the dish is not properly bonded to the structure ground.

 

[ZetaMale]

IMHO, I would lose the GBox

What would you recommend as a Gbox replacement?

 

[Magic Static]

What would you recommend as a Gbox replacement?

Unfortunately there is not a lot of choice in that. I just found the GBox to be inaccurate. I found that it tells you it has reached a position you sent it to regardless of the actual count. I found the late model VBox 7 that there are a few around still, will also miss the count but say they are on position. The early ones did not do this. They would check the count and backup if they had overshot the mark. So that leaves you with the ASC1 which is a very different control unit. Out of all the DiSEqC control boxes I've used the GBox was my least favorite.

 

[fred555]

http://www.titaniumsatellite.com/pr...larity-Controller/p/28731561/category=6743545

 

[Jason S]

Considering the positioner: Being rather new to FTA & C-band and after reading through all the issues about the various positioners, I went with a Titanium ASC-1. No qualms on the ASC-1 after close to a year now. The biggest issue I had was with slop from a worn actuator. With that fixed, the ASC-1 remote stays in A/V cabinet now.

 

[RT-Cat]

Unfortunately there is not a lot of choice in that. I just found the GBox to be inaccurate. I found that it tells you it has reached a position you sent it to regardless of the actual count. I found the late model VBox 7 that there are a few around still, will also miss the count but say they are on position. The early ones did not do this. They would check the count and backup if they had overshot the mark. So that leaves you with the ASC1 which is a very different control unit. Out of all the DiSEqC control boxes I've used the GBox was my least favorite.

Interesting. Goes to show different devices work different with different people. Had the GBox working and went with the ASC-1. Could never get the ASC-1 that is high quality and built like a battle ship to work correctly on my 10 footer. Got tired of over runs and went back to the GBox and it is always right on and has never given me any problems. When it dies, I hope never, it will be interesting on just what to replace it with.

 

[Titanium]

I agree that older G-box controllers were much better. The later models don't use the same firmware and there are several factories that are cranking out lower quality hardware. Impossible to know what model you are buying as the model name applies to several different products and is as generic as the Openbox model names on dozens of different receivers.

RT-Cat, if you still have the ASC1, would you like to test the final beta on soon to be released ASC1 firmware? The testers have indicated excellent results with switch bounce, coasting counts and line noise.

The code has been rewritten to provide increased compatibility with problematic linear actuators and AJAK HH motors. It also addresses the repeat DiSEqC command strings issued by some STBs during loss of signal events or when surfing a satellite list.

Also was curious if you ever checked for voltage potential on the wires coming in from the dish. Since the Gbox and Vboxes are not grounded, this issue is often masked.

 

[Magic Static]

Interesting. Goes to show different devices work different with different people. Had the GBox working and went with the ASC-1. Could never get the ASC-1 that is high quality and built like a battle ship to work correctly on my 10 footer. Got tired of over runs and went back to the GBox and it is always right on and has never given me any problems. When it dies, I hope never, it will be interesting on just what to replace it with.

I have no doubt that what you say is true. But I was trying to get way more performance from my GBox than it was capable of. I'm using a 10' dish for Ku and with the narrow beam width you have with that dish you need accurate positioning. 20 counts per degree is accurate enough but the GBox couldn't quite maintain that accuracy at the speed of the dish motor (AJAK HH180) . I found the VBox-X quite capable of handling 20 counts per degree and landing on the right count every time.

I haven't said much about the ASC1 lately. You are a long time reader in this forum so you know I have been most vocal about the count issues some folks have had, you and me, with the ASC1. You have seen all the efforts to resolve the issue. But I am using an ASC1 for the past couple of months with absolutely no count errors. And let me tell you why. Because while many people were quick to give up on the ASC1 and Brian Gohl and I was one, He never gave up on us. That simple, Brian never gave up on us. The hoops that man has jumped through to make the ASC1 worthy is incredible. But he did and it is! I can say now the ASC1 is the unit I always wanted it to be.

 

[N6BY]

Interesting. Goes to show different devices work different with different people. Had the GBox working and went with the ASC-1. Could never get the ASC-1 that is high quality and built like a battle ship to work correctly on my 10 footer. Got tired of over runs and went back to the GBox and it is always right on and has never given me any problems. When it dies, I hope never, it will be interesting on just what to replace it with.

I also like my GBox V3000, which I purchased many years ago from Sadoun when they were first available. Mine has been flawless so far. If mine ever quits I'll do my best to fix it. A blown relay or capacitor = easy fix. A burnt out transformer might be hard to find a replacement.

I think a lot of the problems people blame on the positioners are due to mechanical free play at the points where the actuator is attached.

 

[ZetaMale]

Is the dish grounded? Is the dish bonded to the structure ground? If not, there may be voltage potential and this may be causing count errors.

Yes. My antennas have always been grounded and connected to the ground rod at the AC service entrance.

Disconnect all wires including coax wires connecting to the dish. One by one, measure the voltage between the structure ground (outlet in the room) and each wire, shield coax stinger/ braid. If any voltage is higher than 0.5v, there is an excessive voltage potential and the dish is not properly bonded to the structure ground.

All AC and DC voltages are less than 300 mV.

 

[ZetaMale]

Interesting. Goes to show different devices work different with different people. Had the GBox working and went with the ASC-1. Could never get the ASC-1 that is high quality and built like a battle ship to work correctly on my 10 footer. Got tired of over runs and went back to the GBox and it is always right on and has never given me any problems. When it dies, I hope never, it will be interesting on just what to replace it with.

Sounds like what happens with solving computer problems - what works for one person doesn't work for another. Anyway, I'd hate to spend $180 for an ASC-1 motor control only to find that it doesn't solve my problem.

 

[Titanium]

Yes. My antennas have always been grounded and connected to the ground rod at the AC service entrance. All AC and DC voltages are less than 300 mV.

Excellent! To clarify, does the ground at the dish have a dedicated bonding wire connecting the ground rod to the structure ground or is the bonding via the ribbon cable?

Does the motor land short of the preprogrammed position or run past?

 

[ZetaMale]

Excellent! To clarify, does the ground at the dish have a dedicated bonding wire connecting the ground rod to the structure ground or is the bonding via the ribbon cable?

Unbroken #2 unsheathed stranded wire from the dish pole to a nearby ground rod (less than 1 foot away) to the AC service entrance ground rod.

Does the motor land short of the preprogrammed position or run past?

Either way. Most annoying - mostly for the wife.

 

[Titanium]

Either way? Wow, that is unusual! USually it is either landing short or running long, not both.

Here is an interesting component that Magic Static found. I haven't tried it, but it sure looks interesting for cleaning motor RFI:
http://www.alliedelec.com/red-lion-...gclid=CKW4rITpvMgCFQNsfgodo3AINg#tab=overview

Magic Static also is building a device that could be easily adapted to your system by adding a 5Vdc power supply. It isolates and reforms the switch closures to provide even switch pulses without switch bounce.

 

[N6BY]

Sounds like what happens with solving computer problems - what works for one person doesn't work for another. Anyway, I'd hate to spend $180 for an ASC-1 motor control only to find that it doesn't solve my problem.

It may not be an electronic problem. If you haven't already, I would recommend checking for looseness where the actuator attaches to the dish and pole. Could be an easy fix, you never know.