H180 Modding ?

[Vipersan]

Ooooo that was lucky ..
found a 99 postion Alsat V-Box 400 GBOX v2000 on Amazon for £26 including delivery ..
claimed 'the last one'
Now on order and due between 12th and 18th sept..

Funny though ..
There is a Vbox 7 available all over the USA ...
Nice looking construction and also 99 channels ..
But unsuitable due to it having a 110v transformer.
Makes you wonder why a European version isn't available..
Not like the Americans to miss a selling opportunity.
rgds
VS

 

[Captain Jack]

It's actually 95 positions 96-99 are used for er... some other purpose. Can't remember.

 

[RimaNTSS]

There is a Vbox 7 available all over the USA ...
Nice looking construction and also 99 channels ..
But unsuitable due to it having a 110v transformer.

Once I've found positioner in USA e-bay, in description it was mentioned 110/220V. So I got i delivered, changed socket plug to European standard and plugged in 220V. Of course it made some noise and lots of smoke. Then I opened case in e-bay, and because in item description was 110/220V I won the case, they returned all my money, let broken item in my hands and even gave me 10$ as a pain-money. What I did afterwards... just changed transformer to one has 12V and 24 or 36V and positioner start to work without any problems.
By saying that.... it is not a big deal to put new transformer in positioner made for USA market. Transformer can be taken from old sat-receiver or any other old electronics.

 

[Huevos]

having so many lnbs on Carl ..some of which are a good distance from the focus ..I'd like to be able to preset elevation for these non focal lnbs..such that one command will instantly adjust both AZ and EL for max signal at these extremes ..

VS, I don't get what you mean. A "non-focal" LNB once adjusted onto the arc will remain on the arc for the entire travel of the dish. If it doesn't the elevation/declination combo must be wrong.

 

[Vipersan]

VS, I don't get what you mean. A "non-focal" LNB once adjusted onto the arc will remain on the arc for the entire travel of the dish. If it doesn't the elevation/declination combo must be wrong.

Agreed a non focal lnb once adjusted will track the arc in the same way as one at the focus ...
But can say 3 lnbs one at the focus ..and one at +5 degrees right and one -5 degrees left of focus in a line on a straight bar ..all track the arc correctly having set the one at focus to do do so ..
I would suggest not ..
..hence the need for elevation correction for the non focal lnbs.
and Ka lnbs on a large-ish dish are less tolerant of error ..
Happy to be corrected if I have got this wrong ..
;)

 

[Huevos]

can say 3 lnbs one at the focus ..and one at +5 degrees right and one -5 degrees left of focus in a line on a straight bar ..all track the arc correctly having set the one at focus to do do so ..

Depends what your idea of straight is. Where you are the arc is pretty flat. LNB line-up would be a mirror image of the arc. +/- 5º means the non-focal LNBs have to receive from 0.2º below the arc, so need to be positioned 0.2º above the arc. So a pretty straight line.

Personally, my opinion is "keep it simple". Anyway let's ask CJ he's gone both ways on this.

CJ, what's easier, position your 3 LNBs so they are all tracking the arc correctly, or use an elevation actuator and twin V-boxs to switch between them?

 

[Vipersan]

As I said already ..
the standard arangement ignoring the tiny variances is neither here nor there in Ku ..
I can testify to this ...but in Ka such a small variation is huge in terms of signal ..
2 clicks of the Vbox will either bring in a signal at 12db ..or kill it completely..dropping the signal below 3db.
Yes it's _that_ critical ..and the larger the dish ..the trickier it gets.
rgds
VS

 

[Huevos]

2 clicks of the Vbox will either bring in a signal at 12db ..or kill it completely..dropping the signal below 3db.

Same on my Ku declination control.

 

[Vipersan]

Same on my Ku declination control.

I find that curious ..
perhaps it's down to the quality of the dish then..
For example I can lock BBC News at 0.8W with the inverto and click 4 above and below without totally losing lock..
This I cannot do with say Muvi Mux at 7W in Ka ?

Personally I think a lot is to do with the target area of the feed horn ..
Ku feeds are twice the diameter of Ka feeds...so pointing needs much more accuracy.

Saorsat installers generally put the Ka feed at the focus of the dish and the Ku lnb as the offset ..
aligning the Ka first and leaving the Ku till last ..it being considered not so critical.

Thinking about it ...2 clicks is about right then for 0.2 degrees ..
I find 10 clicks is approx 1 degree of shift ..
Now I don't know about your system ...but I find I can lock a strong Ku signal within half a degree ..ie approx 4 or 5 clicks and maintain a lock over about 0.8 degrees ...
This I simply cannot do in Ka ...
Have you ever tried Ka Huevos ?
Setting up Ka data satellite links for say Hughesnet or Tooway ...is almost an artform ...and often requires specialist installers.

 

[RimaNTSS]

Once I made test on my 1,5m PFA. I selected 11034V 27500 3/4 from 13*E and started to move antenna by clicking of positioner. Measured signal by Sathero 100 and DM8000. So got fist locks at signal level about 30 and that was side-lobe. After 7 clicks got lock again and on 15-16th cklick signal was at maximum level. See the diagram.

 

[Captain Jack]

CJ, what's easier, position your 3 LNBs so they are all tracking the arc correctly, or use an elevation actuator and twin V-boxs to switch between them?

To be honest, I haven't really touched my elevation actuator since installing the 1.5m Gibby. I only ever use it to eek out weak signals, so I'd say my offset C-band LNBs are tracking the arc fairly accurately. BUT... like VS says, C band is far more tolerant to misalignment than, say, Ka, so it's not a fair comparison here.

 

[Huevos]

Once I made test on my 1,5m PFA. I selected 11034V 27500 3/4 from 13*E and started to move antenna by clicking of positioner. Measured signal by Sathero 100 and DM8000. So got fist locks at signal level about 30 and that was side-lobe. After 7 clicks got lock again and on 15-16th cklick signal was at maximum level. See the diagram.
View attachment 67961

That is not elevation adjustment. How many clicks from centre just depends on the degree to click ratio.

Also I don't understand why the highest frequency LNB is not the focal LNB.

 

[RimaNTSS]

That is not elevation adjustment.

Of course not. I do not have elevation actuator, do not see need for that for small antennas (smaller than 2 meters).

 

[Vipersan]

That is not elevation adjustment. How many clicks from centre just depends on the degree to click ratio.

Also I don't understand why the highest frequency LNB is not the focal LNB.

IT IS ..at the focus ..
ie the XMW Ka band D is at the focus ..
but there is at least one other Ka lnb 5 degrees offset ..and another yet to be fitted also a few degrees offset (Norsat 9000A) ..
Plus the Ku offset by 3 degrees ..as this is not so critical and therefore more tolerant..
The SL3 and the XMW cannot both occupy the focus ..and since the SL3 operates in Ka A and Ka B ..this was chosen to be an offset..
imo ..the most sensible setup I can achieve.

 

[Captain Jack]

I reckon you should get a dish for every LNB you have

 

[Vipersan]

I reckon you should get a dish for every LNB you have

If I had as much acreage as AS ...believe me I would ..
;)
Life is a compromise ...
So is my hobby in a Terraced house backyard

 

[RimaNTSS]

But if there is real need to have elevation adjustments by actuator, than degree per click ratio should be something like 50 or even more clicks per degree. For that reason mechanics should be designed differently than just attaching actuator instead of elevation control screw. IMHO

 

[Vipersan]

But if there is real need to have elevation adjustments by actuator, than degree per click ratio should be something like 50 or even more clicks per degree. For that reason mechanics should be designed differently than just attaching actuator instead of elevation control screw. IMHO

Totally agree Rima ..
but sadly compromise is the best I can achieve..

 

[Huevos]

If I had as much acreage as AS ...believe me I would ..

How many acres is that?

And I know CJ is joking but have to agree (if it were possible).

 

[Vipersan]

How many acres is that?

And I know CJ is joking but have to agree (if it were possible).

I'll let AS answer that ...but I know he has enough area to take in strays ...much like someone with a donkey sanctuary...
lol