USALS on a PC

rlogue

Does anyone have any suggestions on the best way to drive a motorised dish via a PC? I've tinkered with the AzureWave DVB-S2 card but found it could switch between 28.2 and 19 but struggled to drive the motor much further than that.

watty

you need an external PSU repeater that bypasses the 22kHz and the RF and echos the PC 13V or 18V.

I think there is only one PC card on market with +12 OV OV +5V aux connector to supply the power needed. Sorry can't remember name.

A 20V 500mA PSU, 1A 60V NPN 5W or better transistor on heatsink and a couple of resistors, capacitors and 5 turn 3mm coils to isolate the RF should do as PSU. I was thinking of making one for myself. Short circuit protection would be lacking. That would require some more thought.

The PC cards can't supply the motor current. I've seen online photos of "cooked" tracks on Skystar2 that people have tried.

rlogue

Yes well I have got the AzureWave card (a clone of the Skystar S2) that claims USALS comparability but it is only capable of driving the dish forward and back between 28 and 19.

Is there a USALS/DiseqC positioner on the Market?

watty

USALS is just host Program software. If the driver allows the program to control the 22kHz, you can have any diseqc mode your application can do. It doesn't mean it can power the motor. Likely if you moved dish somehow to 0 it would do 5E to 5W. Likely the motor is stalling.


This is the only one I know
http://www.sciteq.com.au/store/product_info.php?products_id=139

There is one on Adverts.ie http://www.adverts.ie/other-electronics/moteck-v-box-ii-diseqc-positioner/188177
(30 to 45mins from me likely and collection only!)

It controls H-H diseqc motor OR a 36V actuator... So it might have a passthrough mode where it passes through the sat card signals. Then it would supply the +13V or +18V and the motor would work.

This German shop might suit you better http://www.satshop.tv/Moteck-V-Box-II-Positioner

Not sure though if it does a cheap Diseqc H-H motor (13V/18V) powered from coax or only 36V. You need to check.

Apogee

Those positioners are for "converting" Diseqc to 36V, not really suitable.

This is more like what you're after, though I've never seen a review as to how well it works in practice.

http://www.stab-italia.com/mostrarticolo.php?codice=F205011

fat-tony

rlogue wrote: »

Yes well I have got the AzureWave card (a clone of the Skystar S2) that claims USALS comparability but it is only capable of driving the dish forward and back between 28 and 19.

Is there a USALS/DiseqC positioner on the Market?

I have a Technisat Skystar HD2 with additional molex connector for a separate feed from the PC PSU. It certainly is capable of driving a standard motor. I have used it in conjunction with DVBviewer Pro to position a motor either through Disecq or USALS commands.

As watty says, perhaps you have a problem with the motor, that it is stalling at a particular point? When you position it at 19 degrees, can you then issue a goto zero command with the software in order to centralise the motor? The only other thing I can think of is that you may have inadvertently set east and west limits in the software (or on the motor) when you initially set it up. These limits are there to protect the motor (and your power supply!) from damage if the dish hits an immovable obstacle while turning.

watty

Regular Satellite PC cards can't supply enough motor current. Apart from models specifically advertised to do it that takes a separate power connector from PC PSU. "fat-tony"'s card is probably the one I saw. It's likely sold also under other badges.

Get the Technisat Skystar HD2 as that's better than a VboxII unless you are upgrading to 36V system.

fat-tony

Even though I have a card with the relevant power connector, I was relectant to use it full time. The motor can draw up to an amp, so you would want to be sure the power supply in the PC is up to it. Most recent motherboards and PSUs should be able for it, especially gaming machines. But if you have a small footprint, low power HTPC it might be risky. I now actually have a twin LNB on my motorised dish and I drive the motor from an old receiver, with a separate feed going to my PC.

watty

Actually you can do that even with a single LNB as long as the controlling receiver is happy with no LNB. You still need 2 x coax feeds of course.

fat-tony

Agreed, but, in my case, controlling receiver is distant from PC setup, so need LNB signal to see quality level if "nudging" the dish via Disecq command;)