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Old 11-15-2012
Frogwatch Frogwatch is offline
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Re: Folding fabric satellite TV dish

Yes, I have done the numbers especially since weird optics is my occupation.
FIRST for Hellosailor. my fabric is more conductive than most metal dishes. Hence, for microwaves it is more reflective.
Figure accuracy is not much of an issue either. For a mirror to achieve best performance, its shape does not have to be better than 1/4 wavelength accuracy (Rayleigh proved it) and that means about 1/2" here. I will easily be better than 1/8 wavelength accurate.
When the fabric is taut, it is very strong and is held rigidly in the frame. It is not a wimpy umbrella-like frame. NASA used that for being lightweight, after all, no wind on the moon. Also notice its poor figure accuracy.
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