8' Channel Master questions...

[McGuyver]

I will be getting a free 8' Channel Master fibreglas dish, complete assy. It's in great shape but I did notice that the surface of the dish has lost much of the glaze, tiny strands of glass are showing on the surface. I'll have to dismantle it to get it home, it looks like they used high quality hardware such as stainless steel for everything.

Does anybody know exactly what is used on the surface of the fibreglas dish to act as a reflector? I was thinking if the surface is degraded, I could paint it with a galvanizing paint first then a flat gray over that to form a metallic/reflective surface. Does this sound crazy or do you think it would work?

Would it be worth while for me to set it up for C/Ku-Band or should I keep it all Ku?
Any input and/or suggestions would be appreciated.

 

[turbosat]

The surface roughness prob won't affect its ability to reflect a satellite signal. I think I would just stick a c-band lnb on it and see how it works. Really depends on how it was made, I think I read somewhere that some fiberglass dishes actually have a metal mesh layer imbedded in the fiberglass, and how big that mesh was will determine how/if it works for KU. I have a 12' I never put together, too dang big/heavy to mess with!!

 

[caddata]

....what is used on the surface of the fibreglas dish to act as a reflector?....

Early ones used screen wire embeded while the later ones used a carbon fiber polyester cloth as the reflecting surface. Not all will be compatable with KU reception, and there's no way to tell other than hooking up a Ku feedhorn to test it.

Harold

 

[gabshere]

yes it seems some fiberglass dishes are hits and others are misses , but this is a channel master and they are/was a mainstream dish builder so maybe it will be good luck post some pictures of it when you get a chance...
i don't think a metalic paint will work, but thats just me thinking i think i remember something about painting big dishes... but maybe someone else will chime in.

 

[McGuyver]

8' Channel Master dish

turbosat, gabshere & caddata, thanks for your input, I will post some pics of it sometime soon, I'll be taking some shots before I dismantle it. The fibreglass is a light beige color, does this give us a clue to a particular type or model?

It did appear to have some sort of reflector material embedded but I didn't look that close to see what it is. Doesn't the reflector surface need to be metallic or can it be of various materials? I always thought that it had to be of a metallic property.

The donor told me it was a Ku-band dish, he didn't mention anything about C-band, so this could be a big +

The reflector is a 4 part sectional with what appears to be a stainless steel LNB mount. I'm really impressed with the quality of this BUD, and the pole mount is a slip over design that cover the entire mounting post.

If it works well, I may just brush a coat of resin on the surface to seal the glass again, then I would dull the finish with steel wool to prevent sun glare, does this sound kosher?

 

[caddata]

Doesn't the reflector surface need to be metallic

McGuyver:

A conductor doesn't have to be metal. Carbon is a conductor, although highly resistive. The brushes in electrical motors are carbon.

Second generation (1980's) FRP (Fiber Reinforcd Plastic) dishes used a carbon impregnated polyester cloth (roving) as the reflective surface. First generation FRP dishes that used metal screen weren't very accurate, the screen laid as it wanted. Not necessarily holding the parabolic curve.

I'm not sure what the current generation of moulded dishes use these days.

Harold