John
Enthusiast.
- Joined
- Jan 1, 2000
- Messages
- 3,742
- Reaction score
- 5,545
- Points
- 113
- Location
- North Nottinghamshire.
- My Satellite Setup
-
Elite 2.2 PF - CM1.8 - CM1.2 - Gibertini 1.25.
Ku - Ka -C & Ext C.
PC cards-TM5402 receivers.
Promax FSM.
- My Location
- North Nottinghamshire.
This is not something new - the ease of a changing polarity mod on these stock 18 GHz Hughes broadband units was looked into some years ago by forum members Vipersan & Llew - - - This is my version of making it a motorised operation controlled from the shack.
The first part of the mod is to remove the Horizontal polarity top half of the Hughes OMT, and use the bottom 'Tx' part of the OMT as a mounting 'foot' onto the main support rail for the other components. The unused ports on the OMT being bunged with absorber and then a metal sealing plate. The OMT will now be operating as a circular to rectangular WR42 transition to suit the WR42 Norsat 18GHz pll lnb. How much of a impact on performance / mismatch of the OMT will have to be observed when final testing is done with comparisons made with un-modded 18GHz units.
The drive motor for rotating the Hughes polorizer is a low RPM 12 volt unit which is reversable and is controlled with a speed controller for added speed control.
Still waiting for some drive cogs and bits to come from China etc but here's a few pics of the project start.
The first part of the mod is to remove the Horizontal polarity top half of the Hughes OMT, and use the bottom 'Tx' part of the OMT as a mounting 'foot' onto the main support rail for the other components. The unused ports on the OMT being bunged with absorber and then a metal sealing plate. The OMT will now be operating as a circular to rectangular WR42 transition to suit the WR42 Norsat 18GHz pll lnb. How much of a impact on performance / mismatch of the OMT will have to be observed when final testing is done with comparisons made with un-modded 18GHz units.
The drive motor for rotating the Hughes polorizer is a low RPM 12 volt unit which is reversable and is controlled with a speed controller for added speed control.
Still waiting for some drive cogs and bits to come from China etc but here's a few pics of the project start.