Need to Clean / Paint feedhorn

[fortyfives]

Just picked up a used Chaparral Corrotor 2 with C & Ku lnb's to replace my old Chaparral c-band feed horn. I have a couple of questions I hope y'all can help me with.

First of all, there is some corrosion (white powdery) down the feedhorn throat. What can I use to clean this out with? It's not bad but I'm guessing the corrosion will degrade the signal. Also, is there something I can use to lubricate the probe that won't hurt it or degrade signal.

What is best to repaint the outside of the feedhorn with? Gray primer?

When I mount the new feedhorn, I'm hoping I can just slide the old feedhorn out of the scalar ring that is currently mounted on the dish, and just slide the new one in since they are both Chaparral's . I currently have the c-band LNB pointing at about 5 o'clock with the dish at the top of the arc. Should I mount the new one with the c-band LNB also at about 5 O'clock?

Thanks,

John

 

[awh]

The white powdery stuff down inside the feedhorn throat probably isn’t going to hurt anything to just leave it alone, chances are that you might do more damage should out hit the probe inside trying to clean it out (I forget what the official name of that thing is! But, I think you know what I mean by ‘probe.’ ).

The angle that the feedhorn is mounted is determined by the polarotor, not the LNBs - you should have a template that came with the original feedhorn and it should work just fine for your new feedhorn as well... if you can’t find the template, (and this is from memory, but I think it’s accurate) point your dish due south and the axis of the polarotor should be about 10 o’clock - it’s not critical, just make sure that when you set skew that you can go well beyond the optimal setting so that the polarotor servo isn’t hitting it’s hard stops in either the horizontal or vertical settings.

Tony
Home Page - http://www.cyberspace.org/~awh/
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[mkm4]

I'll reiterate DON'T TOUCH THE PROBE!!!
It's real easy to screw it up.

Here is the Chaparral Feedhorn Guide:
http://www.chaparral.net/support/trouble/feedhorn.html