Dear list

I have a big problem locking  Patriot  1.8 M dish on Nss703. The EIRP is just too low.

Any ideas  why  ?

If the satellite EIRP is too low in your country or geographic area for a 1.8m dish you will need a larger dish.  Find the beam coverage map for your beam - you may at the beam edge or outside it.

Since you have a 1.8m dish, I would guess that you expected it to work.  Was the size suggested by a service provider ?  Do 1.8m dishes nearby work satisfactorily receiving the same carrier from the same satellite ?

If a 1.8m dish is expected to work where you are then the problem is not insufficient EIRP from the satellite, but some receive problem at your dish.

In this case check:

Dish assembly.  Is the rim flat to 2mm ?  Use crossed fishing lines.  Is the surface join at any segment joint smooth?.   Is it in focus ?   Check dimensions and documentation - feed support struts must be in correct holes etc.  Never 'force' a dish during assembly.  It should fit together delicately and perfectly without any stress.

Feed: Do you have correct type of polarisation (linear or circular)?.  Is the polarisation set correctly (starting position and then adjustment angle in the case of linear) ?

Check for water in the feed, crossed waveguides, crossed gasket, poor F connectors & moisture corrosion in cable.

Is the dish pointed and peaked up ?

If you are using the modem as a signal detector check the programmed tuning and symbol rate.

If C band, there is a possibility of interference from local terrestrial communications.

Best regards, Eric.