mechanical polarotor

Very interesting
 
i work again on my polar system .
I designed my system based on the same principle as DiSEqC rotors (LNB changers).
The assembly is powered by the 18V cable, and the controls are in DiSEqC format for adjusting the skew.
I've included a 0° initialization system upon power-up.
This device is compatible with universal (H/V) LNBs or older single-polarity LNBs.
The position is adjustable between +90° and -90°.
cardpol2.webp
 
today i build my mechanical polarotor for me and for an italian friend .
i drawn a board to decode an non-refenced diseqc command , this order send the skew value.
my board decode and manage a 18V motor (with pulses) to turn a wave guide made of aluminium tube .
The tube is guided by nylon parts and rotated by a toothed pulley.A cam is fixed to the pulley to automatically find the 0° point.
The 18V power supply is taken from the LNB-Changer cable (the changer function is always active).

























 
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today i build my mechanical polarotor for me and for an italian friend .
i drawn a board to decode an non-refenced diseqc command , this order send the skew value.
my board decode and manage a 18V motor (with pulses) to turn a wave guide made of aluminium tube .
The tube is guided by nylon parts and rotated by a toothed pulley.A cam is fixed to the pulley to automatically find the 0° point.
The 18V power supply is taken from the LNB-Changer cable (the changer function is always active).



























Outstanding work, truly excellent, well done.

Couple of questions if you can please help?
1. Have you a picture of the unit mounted on a dish please ?
2. Can the polarotor be powered by your positioner or would the positioner need a modification ?
 
Outstanding work, truly excellent, well done.

Couple of questions if you can please help?
1. Have you a picture of the unit mounted on a dish please ?
2. Can the polarotor be powered by your positioner or would the positioner need a modification ?
1-soon
2- polarotor is powered with 18V (motor is 24V) ,power is taken from either lnb changer ouput or positioner internal wire to rear connector .
i made 2 firmware : use only lnb changer cable (power + command) or 18V from posi + skew command (5v).
the second one is ready to use with all posi !! the first one need an update for the posi firmware .
 
1-soon
2- polarotor is powered with 18V (motor is 24V) ,power is taken from either lnb changer ouput or positioner internal wire to rear connector .
i made 2 firmware : use only lnb changer cable (power + command) or 18V from posi + skew command (5v).
the second one is ready to use with all posi !! the first one need an update for the posi firmware .
Amazing job!
 
The origin of this project is the need to use a universal LNB with an EGIS motor (AZ EL).
During azimuth rotation, the LNB must tilt approximately 45° at its east and west ends.
I copied the principle of DiSEqC motors:
- Command transmitted via 22 kHz
- 18V power supply provided by the cable
- Automatic alignment by a cam at the 0° point.
I had to fabricate many plastic and aluminum parts on a lathe.
I also used JLC aluminum printed circuit boards.
I created an entire software package for my positioner on a small circuit board.
I haven't calculated the cost, but it's not negligible; however, it was a very motivating challenge.
 
Could you possibly "create" the same for Ka band?
 
Could you possibly "create" the same for Ka band?
To receive all up there on Ka band will require four polarities and at least two LNBs to capture the various bands.

I would suspect there is a depolarising mechanical waveguide out there for the mid-band frequency but I've not seen one in the flesh.
 
Yes, depolarizers exist. Without one, it's essentially pointless. Unfortunately, all polarization states are covered in the Ka-band, so H, V, L, and R depolarizers are needed.
I modified Gilat LNBs so that two bands are always possible and both linear and circular operation is possible. They work very well.
 
Could you possibly "create" the same for Ka band?
My solution is suitable for an installation where the Ku band is in the center (I put the C band next to it).
For the Ka band (which I don't have!), you just need to use a smaller waveguide, and why not two parallel waveguides (one linear polarized, the other circular)?
But there are four Ka bands!
So which band should you choose?
 
I found aluminum tubing with an inner diameter of 10.6mm, which corresponds to the Ka band values.
But I only see LNBs with a WR42 input.
Are there Ka feeds, orthomode feeds, etc.?
If anyone has the dimensions of a Ka feed for PF, I'd be interested.
I ordered a SAORSAT LNB with the intention of modifying it!
 
It is for Directv original Ka-band multi-LNB-s only. It upconverts Ka-band output (250-750 MHz) to receiver's 1650 - 2150 MHz range.
 
With the motorized polarizer, it can be used with two types of mounts and two types of LNBs:
- Equatorial mount and AZ-EL mount (Egis).
- Dual-polarization LNB (Universal) and single-polarization LNB (Norsat).
1- Universal LNB on a polar mount with or without correction.
2- Universal LNB on an AZ-EL mount (Egis) with correction.
3- Single-polarization LNB on a polar mount with horizontal and vertical correction.
4- Single-polarization LNB on an AZ-EL mount (Egis) with horizontal and vertical correction.
 
I found aluminum tubing with an inner diameter of 10.6mm, which corresponds to the Ka band values.
But I only see LNBs with a WR42 input.
Are there Ka feeds, orthomode feeds, etc.?
If anyone has the dimensions of a Ka feed for PF, I'd be interested.
I ordered a SAORSAT LNB with the intention of modifying it!
Whilst for an offset dish, the dimensions within the last page may be of use.


Btw if you are looking to fit the Saorsat LNB on the end the WR42 suffix is irrelevant
 
I redesigned my interface board to mount it on the LNB bracket.
I designed it to support two types of interfaces:
either for an EGIS motor (24V power and Skew signal)
or for a DiSEqC controller (of my own design) connected to the line intended for the LNB changer (18V power).
mot01.webp
 

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