Dew cap/shield

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Dew cap/shield

Postby webboid » Sun Jul 25, 2010 9:13 pm

I wonder if someone could tell me what the best material to make a dew cap for a Skymax 127 would be. Thanks in advance!
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RE: Dew cap/shield

Postby revs » Mon Jul 26, 2010 9:10 am

I've been wondering the same, actually :)

BUMP!
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RE: Dew cap/shield

Postby brianb » Mon Jul 26, 2010 9:43 am

Camping mat ... cheap & very effective. Roll into a (slightly undersized) cylinder & stick the edge down with duck tape. The stuff is slightly elastic, making it a few mm undersize will make it stay in place without slipping or drooping. Or use Velcro for an adjustable fitting that can be stored flat.

Ordinary corrugated cardboard is also good except that it disintegrates after a few soakings. Painting it improves the life. (Outside white, inside flat black)

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RE: Dew cap/shield

Postby webboid » Mon Jul 26, 2010 10:16 am

Thanks very much...all makes sense.
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RE: Dew cap/shield

Postby revs » Mon Jul 26, 2010 10:33 am

Yeah, cheers. How long should it be?
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RE: Dew cap/shield

Postby brianb » Mon Jul 26, 2010 1:03 pm

[quote]How long should it be?
[/quote]
For maximum dew protection, about 4x the diameter. This is too much when there is a wind blowing, the great thing about making your own is that you can have a range of different lengths to suit different conditions. 2x the diameter is a good compromise, 1x the diameter is good when there is a wind blowing. Most commercial dew caps are far too short to be effective, and are often made from a material which is a good conductor of heat (metal) which reduces their effectiveness.

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RE: Dew cap/shield

Postby sftonkin » Mon Jul 26, 2010 1:36 pm

Make the whole thing about 5x the diameter, then slip it up and down the OTA to achieve a length that is suitable for the conditions.

Alternatives to foam mats:
[*] The plastic that A4 and A3 document Wallets (folders) are made from.
[*] Corrugated plastic (estate agents' boards are often made from this) -- same structure as corrugated cardboard, only it's plastic.
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RE: Dew cap/shield

Postby revs » Mon Jul 26, 2010 4:40 pm

OK cheers guys ;). I'll see what I can dig out.
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