Dew Settings - UK

[AstroKane]

Hi All - I recently added a dew system to my setup. I picked up the HitecAstro Dew controller with Astrozap straps which will be used on my SW ED 80.

I would be grateful for any advice on dew settings - particularly if you use this device and especially for folks in Southern UK .

•  Do you have them on all the time, or
•  A certain temp relative to dew point.
• Do you often employ them for summer sessions, or more autumn and winter.
• What settings should I be using, this device doesn't seem to display a temperature.

Many thanks for any tips/advice.

Clear Skies

Kane

[souls33k3r]

Personally on a hot summer night i wouldn't bother with it but come winters i start at about quarter and then gradually increase in through the night. Never had a dew problem when i used to own the HitechAstro dew controller.

Now that i have bought the Pegasus Powerbox, i let the sensor worry about that.

Hope this helps.

[2STAR]

Hi, I have the Kendrick Dew Control and  a dew strap, If using in the winter on my SCT I turn it on low setting ( doesn't show what temp) and increase as and when necessary depending on how much dew is around.

I haven't  used a dew strap on my 80mm refractor yet, but come the Autumn/winter I will use as above, although the refractor is not as prone to dew as the big SCT.

Some folk reckon that warm air currents can be generated by too much heat on the OTA being transferred internally, but I have not experienced that personally.  

Just turn it on low and keep your eye on the glass and adjust accordingly, it all depends on the individual conditions each night.     

It's also worth buying a small cheap hairdryer in case of sudden mist up

eric

[Paz]

I've learned settings by trial and error but as a rule the minimum heat you can get away with the better as you can run on a smaller battery that way. Over time the amount I use heaters has got less and less as I've learned what is necessary.

Worth noting is that as well as heating to stop dewing up when outside there is also the potential in colder weather to use heaters to stop your kit dewing up as soon as you bring it inside where it is warm, and this latter point I apply to my eyepieces, I keep them nice and warm in winter as it doesn't affect the views but does mean I can pack things away quicker.

[AstroKane]

Cheers for that input gents, sounds like it's a bit of trial and error until you become accustomed to your personal rig - that's great. I just didn't want to launch in with newbie mistakes.

I am that summer preparation phase, gearing up for another winter season! You know the drill! ?

Clear skies 

Kane 

[Jkulin]

For Refractors I wasn't so critical about how much heat I pumped out until I started getting problems with my primary on the Reflector.

Following some advice I had from @peter shah, I bought a Kendrick Controller for it and when it chooses to work (See my review) it does stop any distortion of the primary, I used to use a secondary heater, but have just purchased from dewheater.com one of their new dewshields with built in heater as it doesn't touch the mirrors and should stop any dew.

For my refractors I try to maintain no more that 10 degrees difference from the ambient and the temp reported on the front of the lenses, I did this buying some cheaper LCD temp probes with LCD display as below, I have one on all 3 of my scopes under the main dew heater: -

https://www.ebay.co.uk/itm/Mini-LCD-Digital-Temperature-Thermometer-Outdoor-Indoor-Meter-Probe-UK-Stock/302604262698?hash=item46749e9d2a:g:1QwAAOSwcIJa6W7L

£2.38 each and now with a quick glance I can tell the temp of the dew heater, if it goes up too much then I turn it down, the display is mounted on the side of my OTA and easily read.