POTY reflector dimensions

[M5TXJ]

Hi all,

In the original drawings for POTY the reflector is shown as a circle of 105mm diameter. I see that suppliers such as Passion Radio are selling POTY kits with an almost circular (4 straight edges) reflector. I'm assuming this is because 100x100mm material is easier to source, can anyone confirm these non true circular reflectors are 100mm across the flat edges?

73 Dave.

[radiogareth]

By " non true circular" I assume you mean square
Be interesting to know as its (a) less waste metal in the making and (b) I have some 100mm wide copper sheet from another job and (c) saves me messing about with the 4-Jaw chuck....
Gareth

[g0mjw]

There was a reason I specified 105mm dia. Mess about with the original design at your own risk.

Mike

[M5TXJ]

Hi Mike,

I understand that, I'm just wondering the rationale behind the different reflector.

73 Dave.

[g0mjw]

I think you are right - 100mm stock was cheaper to get hold of. I don't know what the effect is on the pattern or circularity. Might be OK, might not. It's all about the wavelength.

Mike

[keng8vdp]

Some LNB arms & LNB clamps are such that the LNB (poty) is very close to the support arm. (the holder doesn't sit very high above the arm) this means the reflector on a Poty fouls against the support arm. Even worse with a circular reflector. You can make it fit BUT it might end up not being quite at optimum focal point.
I found the squared off type allows greater clearance as you can position one of the "flats" towards the arm giving slighly better positioning of the focal point. Other than that, if you have a type that prevents this the only solution is to modify the arm.
Hmmmm, such fun !

A Bacon sandwich can make problems less problamatic.

Ken