Dish warped?

[timo_w2s]

I've noticed this summer reception on my 80cm clear plastic dish has been a lot worse than usual but it doesn't seem like it's moved however if I pull the dish together from the sides to make it more curved I see signal levels go back to what they used to be. As a temporary fix I've placed two blocks of wood that push it away from the wall by about 5-10mm each side (see photo).

It's been quite a hot summer and my balcony often gets over 35C hot and even more in the sun, especially when it's closed with glass panels off like a greenhouse. The plastic is quite flexible. Anyone think my dish might be flattening out in the heat?! I've been thinking of replacing it with a TD88 (it should just about fit on my balcony) for a while, and I'm hoping this would hold its shape plus give me a bit more gain. I can't physically go bigger than that, there just isn't any room.

Any thoughts on what is going on?

 

[Lazarus]

The shape of the surface, allied with the architecture of the rim, should be inherently resistant to warping, so I'd be surprised if that's the root cause.

But I can't offer another explanation, either!

 

[Channel Hopper]

I notice there are a few cables appearing from the front of the dish, the LNB and associated clamps may have something to do with the warping, however any plastic dish is going to be affected adversely by temperature extremes

 

[timo_w2s]

There are 6 LNBs on the LNB arm but I've added an extra support to take the weight (as seen in the bottom of the photo) but the LNB arm itself doesn't touch the plastic parts of the dish as it is fixed directly to the back bracket. I can wiggle the arm (when my extra support is removed) without moving the dish face so it shouldn't influence it too much.

 

[timo_w2s]

The shape of the surface, allied with the architecture of the rim, should be inherently resistant to warping, so I'd be surprised if that's the root cause.

But I can't offer another explanation, either!

Perhaps this type of thin plastic is just too flexible? The structure doesn't seem to offer much in the way of stability if I poke it with my finger but being plastic it always bounces back to its usual shape, or at least I thought it did...

It's given me 4 years of service without any obvious changes in reception and it's been through a couple of other hot summers but perhaps not as prolonged as this year.

Oh well, need to find a supplier of dishes here in Helsinki (in the past I've brought my dishes with me from the UK).

Edit: (The casual satellite user looking at high power satellites isn't going to notice these minor changes, but when I'm trying to get every last drop of signal this change means a loss of channels)