PDA

View Full Version here: : Telrad dew shield...worth the investment?


togo54
28-11-2005, 01:14 PM
While observing tonight in dropping temperatures my Telrad went from dewed up to frozen over in a matter of minutes. Is a dew shield for the Telrad worth the investment considering the humidity (and winter) here in the Pacific Northwest?
Thanks
Tom

rmcpb
28-11-2005, 01:26 PM
Well, not being familiar with your conditions I can only say that my Telrad is essential for my observing and is protected at all costs. I have made a dew shield that is simply a piece of cardboard that is velcroed in a loop over the whole length of the Telrad. This protects the finder from falling dew and is very simple and cheap to make.

I'm sure that the commercial heaters and shields are probably better but not for the cost :)

slice of heaven
28-11-2005, 01:44 PM
Dunno about that, 10yrs of foggy screen and wet rags was more than enough for me, the dew heater is value for money.

ving
28-11-2005, 02:12 PM
i'd say yes.

togo54
28-11-2005, 02:32 PM
Thanks for the replies folks.
It's currently 26 F outside now (I'm not into metrics) :). The inside of the windshield of my 2001 Dodge Ram Quad cab will be frozen when I get up to go to work in 8 hrs. Dew gets everywhere...:(

acropolite
28-11-2005, 04:10 PM
I'd say move to Oz Tom, the weather and skies are better here...:D

rmcpb
29-11-2005, 09:59 AM
With weather conditions like that I would put in a formal protest to someone. Don't know who, but SOMEONE :)

togo54
29-11-2005, 02:07 PM
rmcpb
I put in a formal protest to the local weatherman....but as we all know, weathermen are idiots worldwide :).

acropolite
Believe it or not...moving to the land of OZ has been a dream of mine for the last 30+ years (even before the Crocodile Dundee movies) :). Unfortunately I'll have to hit the lottery before it will happen.

wavelandscott
29-11-2005, 03:49 PM
Togo54,

Some sort of dew prevention device is in order...I have used one of the store bought dew shields and dew shield +...they work well. Are they any better than when I used an old foam can holder (stubby holder)?...I am not sure...yes, they do look nicer but it is no more (or less) functional than the foam and the foam does make a statement of its own...do get something for dew.

If you have electricity with your scope, you can buy (or make) a heater...Moonlite used to sell them...I can't remember who makes them now.

Lastly, yes, Australia is a great place to live but so is the PNW...oh sure, the beaches are better here and the climate is more moderate for most of the country (compared to PNW) and...after more thought, you are right to begin with...Australia is a better place to live...

RAJAH235
30-11-2005, 09:22 PM
Tom, see attached for details of Telrad Heater....... The 2 supply wires are Supa Glued to the inside of the 45 deg grooves on both sides & routed to the centre of the unit. A small slot is cut in the centre of the lid, where it slides home & the wires taken to the socket which you mount in the side of the box.
If you need a bit more heat, use 39 or 33 Ohm resistors. All are just 1/4 watt types.
Specs.> 12 volts @ 50 mA / 600 mW.
HTH. :D L.