Motorised dish not moving with lnb plugged in

There ya go Anaksanamune , port #1 is labeled.

Trust1 try it with more then one receiver attached, see what one supplies the DC current, or do all.

Maybe we should do this in a thread in the tech section.....And I wish I still had access to my old lab.
 
@Anaksanamune :
Well, as long as this power supply 'controversy' isn't clear (priority over port #1, or 'divided' over all ports? [ I'm excluding my 'highest voltage wins', by now] ), try ALL suggestions given in this post! :)
And please inform us of the results, so we can learn from it!

@Terryl :
Even if the RF wasn't probably working with the test by @Trust1 , the results nonetheless show some kind of 'sharing currents evenly'. How would you think live RF would affect the currents? I have difficulty theorizing that all (or most of) the current would then suddenly go to port #1.

I've looked at some 6 quad and twin LNBs I've lying about here, and only ONE has numbered ports, BTW.

greetz,
A33
 
Everything for the sience !
@ Terryl , to keep you satisfied and a fresh nose for myself , I dragged out this afternoon 7 receivers , a satmeter and a TV into the garden .
Attached the octo lnb to the revolver on my 1.2 CM , at that moment pointed at 4.9º E with signal .
No different result , when all ports are powered , all ports consume the same amount of current , approx. 52.8 mAmps

octo lnb current test garden.webp
 
Cool, well then someone may have found a way around the power supply bucking problems with more then one analog supply hooked into a system.

I would love to see an internal schematic for that LNB.

And an old RF engineer can learn new tricks.

BTW how do you have the current meter hooked into the system??
 
Terryl said:
BTW how do you have the current meter hooked into the system??
Click to expand...

just used a empty housing of a diseqC switch with 2 leads soldered to the center point of the first 2 F conn.
Made between the other F connectors a special splitter for other experiments .

lnb current bench test.webp
 
@Terryl : Maybe an LNB uses the 'droop share method'?
One of the three methods mentioned here: http://www.switchpwr.com/parallel.pdf (Google sometimes is your friend)

BTW. I read quatro LNBs "need" only 9 to 10 volts, to function properly. Maybe the same applies to quad LNBs. That leaves room for the 'passive' power sharing circuitry.

Greetz,
A33
 
Most work internally at +5 to +6 volts, with some in the +3 volt range on the IC's, it's the transponder selection voltage at +13 or +18 volts that you need to worry about, if those drop below the threshold (usually a half to a volt below) your transponders won't switch right.

Here stateside we sometimes use an OEM LNB that has 3 heads and is a DC current hog at 750 mA, when used with a standard FTA receiver the DC current supplied is only 500 mA. so you can see the problems we get.

The OEM receiver that is used with this type of LNB has a 1.2 amp output, and when it detects this type of LNB turns the DC voltage supply to the LNB up to 20 volts as it does not use the voltage switching for the transponders.
 
Well, I hope we will hear from @Anaksanamune if the power issue really is the problem.

a33 said:
With a modification of the motor, it could be made to turn on external power, I guess. You'd need an extra cable to the motor, though.
Click to expand...

Three ways for modifying motor power that I know of: see this post (and the entire thread, and also the linked thread in the post): Antenna motors - power consumption - SatsUK

Greetz,
A33
 
Simplest solution to this would be to go with a simple dual output LNB feeding a 2x8 (or 4x8) externally powered switch, the #1 receiver can then be feeding the DC power to the motor, and also be connected to the switch, the switch being powered externally with not put a strain on the primary receiver.

It would go...... receiver..>>>>>motor..>>>>>switch..>>>>LNB, signals from the LNB would go to the powered switch then out to the other receivers.
 
Hi all,

Thanks for the various replies, I was away for a bit and then got distracted by life...
Turns out it was just the linking cable between the motor and LNB (also swapped the input to #1, but not sure if that made a difference).

I'll probably be back with some more questions at some point, but for now I have it working in principle (Astra 28E, Thor and Hotbird).
As it is up on the side of the building I may wait for better weather before fine tuning the alignment to pick up the weaker sats.
 
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