sailor said:
Hi Rolfw. Thanks for picking up.Just trying to educate myself about dishes.
1. What is better material
Depends on what you want?
Light weight - aluminium.
Low cost - steel
Durability - sheet moulded compound
Rigidity is also important.
No choice there. It has to be parabolic!
3. Is mesh as efficient as solid metal.
No. But that applies only if you compare like with like. In general, if you take a metal dish and punch holes in it, you'll make it slightly less efficient. Holes are for cosmetic appearance.
4. What affects gain and sensitivity.
Oh dear. Shape, rigidity, LNB feed horn matching, LNB shadowing (on a prime focus dish). Generally, an offset focus dish is more efficient than a prime focus dish because the LNB doesn't block part of the signal. But then you get Cassegrain and Gregorian dishes which are the most efficient but have drawbacks (such as size, weight, appearance and cost).
I recommend you read as much about it as possible in books, as I have over the last year or so. It's a minefield. There are dealers out to fleece you and there are people with a little knowledge (but not enough - like me and Rolf!) who might mislead you.
Fred