Need help finding replacement OMT/Feedhorn

I hope someone can help you with the parts you need.

The picture on this page may help clarify your requirements VSAT feed assembly

The Prodelin 1132 dish has an f/d ratio =0.8 and needs the matching, large, feed horn diameter, which is slightly larger than the older feed horns for older f/d=0.6 dishes which have poor cross-pol performance.

The OMT assembly shown has the important transmit reject filter located in the LNB side arm to protect the LNB.  There is a supplementary filter, in this example, in the transmit port to further suppress spurious power from the transmit BUC.

Please will anyone help with hardware parts ?

Best regards, Eric.

The ebay feed horn is too small diameter.  It looks like a Prodelin receive only horn for use with f/d=0.6 antenna reflector.

The ebay OMT/filter appears suitable, but you need to verify if the circular waveguide joint will match up with the Prodelin Feed horn as shown in my picture. Do you have such a correct Prodelin horn now ?

The Patriot part is intended for use with a Patriot dish, not Prodelin.  I don't know if is suitable.  If it is for a Patriot dish with the same F/D as your Prodelin, then it would be worth a try but your problem will then be getting the focus right.  The phase centre of the feed (its focal point origin) is not normally documented for public use.

The feed horn and associated dish should be regarded as a strictly associated with one another and always bought simultanously.  If you mix and match you will either get low gain or high sidelobe interference, or both.   If you use too small diameter feed the beam will be extra narrow but gain overall will be low because much power gets wasted past the side of the dish.  Sidelobe interference, ground noise and cross pol will be high.  If the feed is too large then the beam will be broad and the gain will be low because only the middle of the dish gets illuminated.  Sidelobes and antenna noise temp and cross-pol will be low however.

The correct feed for the dish will give the best results.

Best regards, Eric.

I don't understand.

The transmit BUC normally has a square flange and rectangular waveguide.

The transmit input port on the OMT is also a square flange and rectangular waveguide.

Have you got one of the new Andrew TRIAs which combine a BUC and LNB in the same device?.  These units have a circular waveguide interface that goes to the feed horn via an adaptor flange.  No OMT or filter is needed.  It looks really neat.  The Andrew TRIA should come with a separate accessory box containing a set of interface flanges to suit all feed types plus two dongles to set whatever LNB LO frequency you want and even co-polor or x-pol operation in some models.

Best regards, Eric.