Installation of a V Box II

[Norm]

The positioner in my BEC receiver has failed. I've taken a look inside and there are unfortunately some charred components on the positioner board; I have also stripped the 36V motor and it appears OK (ie clean with no water ingress). The failure didn't happen when moving the dish which would also suggest that the motor itself wasn't the cause. After replacing the fuse in the receiver, it still works OK (and the dish is pointed at Hotbird).

After thinking about it for a few days, I have decided that possibly the best option is to go for a V Box II and plod along with the BEC receiver which still seems to meet my requirements.

The question is - is this a sensible thing to do? Are there any drawbacks in using the V Box or is it, as far as the user is concerned, just an invisible item in the receiver / dish chain, once it is installed and set up?

 

[BGonaSTICK]

As far as I know, the VBOX II is a DiSEqC to 36V converter (i.e. takes DiSEqC commands from your receiver and converts them to commands used to drive a 36V motor) so unless your receiver also has DiSEqC 1.2, it won't automatically drive your motor by changing channels.

It also acts as a stand-alone 36V positioner, so as long as you're happy to move the dish 'manually' (though you can get an optional remote control) then it should be an ideal solution to your problem. It would also allow you to upgrade your receiver to any other DiSEqC receiver in the future and retain your 36V dish setup.

 

[Norm]

Thanks for your reply. Yes, the receiver does have a DiSEqC 1.2 option, I should have mentioned that. I just wanted to ensure that I wasn't missing something that was pretty much common knowledge plus I don't have much of an understanding how DiSEqC works - in simple terms, I presume that the pulses must be counted to give an inferred position since there is no feedback?

 

[BGonaSTICK]

The DiSEqC protocol actually does have a provision for feedback, but it's not utilised in most common V1.2 implementations.

There is a mixture of relative and absolute positional commands by signalling digital codes (or pulses as you say) to the DiSEqC device. There are also a number of ancillary command types, most of which are specific to a particular device-type (e.g. for motors, there is a 'store position' command and a 'stop driving' command). Devices have unique addresses, and commands can be targeted toward any device.

For a real rough and ready breakdown of what they look like, you could read my simple guide in the dish setup section. A read of the Eutelsat DiSEqC standard is also interesting, even though it appears to have been written by a Muppet in a straightjacket.

STICK

 

[Norm]

Thanks again, Stick. I read your guide and to be frank, I struggled a bit to get my head around it. But the V Box II arrived yesterday; I'll maybe find some time over the weekend to have a play with it.

 

[BGonaSTICK]

Cool. Let us know how you get on.

The most popular of the DiSEqC commands (the goto x.x command) is absolute as opposed to relative, i.e. they say 'go direct to Birmingham City train station' as opposed to relative commands which say 'take the third on the left and past the butchers'. The former command does not rely on knowing where you are to start with, wheras the latter most certainly does. The sat-equivalent of the former would be 'goto 19.2E'.

An example of the latter would be 'drive 7.2 degrees West' (of where the dish is now). This is more like the 36V motor setup where pulses are used (counted) to reference an offset from say due south.

There is another layer of control beneath what the 'DiSEqC' user sees which is something else, and which I have no idea about!

HTH

STICK