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Old 19-08-2012, 10:19 PM
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Nico13 (Ken)
Galaxy Hunting

Nico13 is offline
 
Join Date: Jul 2009
Location: Geelong region.
Posts: 947
Home made dew straps

Further to my early trials with a proto type single dew control I had made a 4 channel controller that is working well but I had also made my dew sraps to go along with the whole setup.
So I thought I'd better show the making of the straps as well as the cost saving is significant.

The Nichrome wire I got from Jaycar a 4 metre pack for around $5.00 did the job (13.7 ohm per metre)
I made two different type of straps, the first were taped directly to the scopes with a layer of duct tape as an insulating base with wire over that and then more tape to hold it in place, a terminal block and a connector and it was done.

After I had made the four channel controller I had added a new guide scope to the mount so another strap was needed so I decided to see if I could make a removable one and so the first layer of tape was fitted sticky side out wire added and a couple of layers of tape over the top with a Velcro strap added into it to allow easy removal.

Average wire length has resulted in about a 15 ohm load and running those at 6V or less about half of the controller output of 12V they are putting out 2.4 W at 0.4A.
But typically running at around 4V giving about 1W output at 0.26A and working very well at that.

The first shot is the Stuck to the scope version on my ED80, the next couple of shots are of the removable one fitted to the ST80 guide scope.
The one on the SCT 8" is also stuck down. I may make these removable at some stage.
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