Re: ATM 3-Vane or 4-Vane Spiders

["Ken Hunter" <kb7h@onemain.com>]

Try using fiberglass vanes (as in printed circuit board material). Leave the
copper on the end to solder it to the hub and carefully file the leading and
trailing edges so that they are rounded somewhat and do the same experiment.
Then get back to us with your results. I'll then make my results known too.

Ken Hunter

----- Original Message -----
From: "Jim Fitch" <jf@arn.net>
To: "'Nils Olof Carlin'" <nilsolof.carlin@telia.com>; <Myosin@aol.com>;
<scot@vquill.com>; <atm@shore.net>
Sent: Tuesday, October 09, 2001 2:49 PM
Subject: RE: ATM 3-Vane or 4-Vane Spiders


>
> >
> > > The mass of the vanes radiates to the sky and is a bit
> > > cooler than ambient air and consequently the vanes are
> > optically much
> > > "thicker" than their physical thickness.
> >
> > Anyone seen this in reality?
> > Nils Olof
> >
>  I insulated two vanes of a four vane spider with Black Flocked Paper to
> see if I could demonstrate any thermal effects on the diffraction
> spikes. Even though the insulated vanes had a thicker profile the
> corresponding spikes appeared dimmer and were thinner and longer. Unless
> I looked at the wrong spikes (I don't think so) I think the temperature
> difference of the vanes does effect the size of the diffraction spikes.
>
> Any other findings?
>
> Jim Fitch
> Amarillo, TX
>
>