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Re: [APML] Home made Dew Shield?
Thanks Bert, I have been very happy with the wire. On scopes I have made
some permanent heaters by first running a ring of tape around the body of
the scope as close to the lens as possible. This provides an insulating
surface that heat can still get through. Then I get the desired length of
wire and coil it around the scope making sure no two turns touch each other.
Once this is done I cover the wire with a second wrapping of gaffer tape. On
top of this I put some adhesive lined foam tape.
The end result can be seen here at
http://www.tradepart.com/techinfo/scopeheaters.jpg
You can see a band of foam around each les on the two scopes. At the end of
the Nichromium wire I attach a normal wire that goes to the battery. The
whole system works very well. Last weekend I found the blue scope had dewed
and thought my faithful system had been beaten by the weather. Happily it
was a bad connection and after a quick repair it cleared itself in about
half an hour.
Regards
Monte
----- Original Message -----
From: "Bert Katzung" <katzung1@attbi.com>
To: <astro-photo@seds.org>
Sent: Wednesday, August 14, 2002 8:26 AM
Subject: Re: [APML] Home made Dew Shield?
> Hi People:
> I am just coming into this thread, so I may be repeating information, but
> here are a couple of good sources for home-made dew zapper information:
> http://www.seds.org/billa/dp/dewpower.html
> http://users.netconnect.com.au/~taylor19/workshop.htm
> http://webhome.idirect.com/~rsnow/scopeheater.html
>
> Source of nichrome heating wire in rolls:
> http://www.omega.com/ppt/pptsc.asp?ref=NI60&Nav=temh03
> The temperature/resistance specs for this wire may be found at:
> http://www.omega.com/Temperature/pdf/NI60.pdf
>
> Hope this is useful---
> Bert
>
> Bert Katzung
> katzung1@attbi.com
> www.astronomy-images.com
>
> ----- Original Message -----
> From: "Monte Wilson" <montezinho@bigpond.com>
> To: <astro-photo@seds.org>
> Sent: Tuesday, August 13, 2002 2:06 PM
> Subject: Re: [APML] Home made Dew Shield?
>
>
> > All I know is the stuff I used is 14ohms per metre. So I guess you might
> > want 4ohms per foot. The slightly thicker wire will be easier to work
> with.
> > I would call them and tell them what you are doing they will have some
> > thoughts.
> >
> >
> >
> > ----- Original Message -----
> > From: "Roland Roberts" <roland@astrofoto.org>
> > To: <astro-photo@seds.org>
> > Sent: Wednesday, August 14, 2002 5:30 AM
> > Subject: Re: [APML] Home made Dew Shield?
> >
> >
> > > >>>>> "Tim" == Tim Hart <Tim.Hart@haworth.com> writes:
> > >
> > > Tim> That is VERY cool! I've even found a supplier!!
> > > Tim> http://www.wholesalepartsandfilm.com/wire.asp
> > >
> > > Okay, so where do I find specs for Nichrome wire? In particular, this
> > > supplier has wire from 0.032" to 0.040" and some specified as "soft"
> > > others as "1/2 hard".
> > >
> > > Then there is also Nichrome ribbon....
> > >
> > > I'm assuming there is a resistance value of the form
> > > ohms/(cross-section x length) that I can use to calculate the
> > > resistance of my wires....
> > >
> > > roland
> > > --
> > > PGP Key ID: 66 BC 3B CD
> > > Roland B. Roberts, PhD RL Enterprises
> > > roland@rlenter.com 76-15 113th Street, Apt 3B
> > > roland@astrofoto.org Forest Hills, NY 11375
> > >
> > > -- APML Archives at <http://astro.umsystem.edu/apml/> ---
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> >
> >
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> >
>
>
>
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