Old SMW feedhorn compatibility with modern H&V C120 LNBs?

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This is the feedhorn off the SMW OA-1050 I got recently.
I have an inverto Red Quad LNB that I would like to try it on.

Looking at the LNB end of the feedhorn, the waveguide seems squared off.
Does this mean that only one polarisation (e.g. horizontal) comes through? Is that what the Fe-rotor fitted to the feed horn is for?
Indeed, in the old SMW LNB only seems to have a single antenna inside to match.

If so, I supposed it will only work with H or V polarised transponders.

Am I correct in this guessing?
 

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Ok, so I slapped the feed horn on the inverto, and put it on the dish.
12207V (Sky News) came in as with any other LNB, but not a sniff of 10773H (BBC1 etc)
I then tried to turn the feed 90 degrees, but the feedhorn mounting holes seems to be 'keyed', ie. slightly offset so that the feedhorn only goes on one way...
Anyway, with two screws there was still nothing (above background radition) on 10773H, and a 10db reduced signal on 12207V.
Maybe the rotor (which needs a hacksaw to remove) does something, or maybe the feedhorn only works in one direction without the rotor.
In any case, on to other experiments...:)
 
Yes, that's a rectangular WR75 output from the XFR-45 to the LNB. Depending on how you mate it to the Inverto, you will only get a fixed polarity, H or V. If you have a receiver with ferrite control to the polariser, if it's mated in the horizontal plane, twisting the polarisation will block the wave when you switch the LNB polarity in your STB. So you would have to re-mate the XFR-45 90 degrees.
 
Ok, thanks Llew for clearing that up.
It sounds a bit cumbersome to use the XFR-45, the main goal was to use the 0.5 f/D ratio of the feedhorn to get full illumination of the dish.
I think I will park the SMW OA-1050 endeavours here then (1m dish not fun enough), and re-use the mount for the CM instead, but that's a whole new kettle of fish.
 
Drill it out, the template is already apparent from the images.

(and rip out the ferrite stuff as well)
 
Channel Hopper said:
Drill it out, the template is already apparent from the images.

(and rip out the ferrite stuff as well)
Click to expand...
How precise does this need to be?
Can this be done "by hand", or does it need to go into a shop with the proper equipment?
Dish might turn usable...
 
Have a go, you can't do much harm at all if you are careful.
 
Well now, I wasn't relly thinking free-hand drilling :)

I think I will ask my father in-law - they have a pretty elaborate set of drills where he works (seal factory). I'm sure they have something to remove the ferrite stuff with as well :)
 
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