Importance Of Dew Heaters

[Keshdogga]

Hey IIS,

I've been taking the time over this rainy period to get those few little accessories that will make life just that bit easier when imaging. So far I've gotten myself a Bahtinov mask which should arrive soon :D:D but now i'm also thinking of investing in some dew heaters. The two times i've been able to get my gear set up I've had a hair dryer handy that was more than useful but It's pretty inconvenient. So anyway, I was wondering if someone could send me to the right place for some decent dew heaters that'd suit my SW ED80. I'm taking the easy way out here and asking the forum first instead of doing more of my own research but I think peoples opinions are the best way to make these kind of decisions :) Thanks for the continuing help everyone :thumbsup:

Cheers
Casey

[erick]

A Thousand Oaks controller and DewNot heater straps. That's my recommendation, Casey.

[Keshdogga]

Thanks for that Eric :thumbsup:

What size straps would suit an ED80? I think the OTA has a exterior diameter of 110mm so would a single 5'' strap work or is it common to have several straps of different and identical lengths?

[[1ponders]]

I have both Kendrick and Thousand Oaks (4 port both) and they work a treat. When you get a strap they are normally marked "for a 3" (75mm) scope" or for a 4" (100mm) scope". Easy way is when you order your controller just tell the store you want a dew strap for an ED80. They will know what size.

[Alchemy]

Ive got a couple of the digifire Kendrick systems.... Probably overkill for a single scope, but they work a treat ( both have 4 ports each and have 10 settings each channel) , you can buy smaller units with the straps as previously recommended.

[Keshdogga]

Thanks for clearing that up Paul, It's actually on your recomendation that I'm looking into dew straps :)

Checked out the thousand oaks page http://www.thousandoaksoptical.com/dew.html Is there any place in Aus that deals them? My Astro Shop has them for $189 but maybe ordering from the US could prove cheaper given the exchange rate :shrug:. It's $109 from the US without postage. Postage would be the killer here I assume.

Also, same situation with the Dew-Not http://www.dew-not.com/Order_Form.htm Is there an Aussie dealer anyone knows of?

EDIT: Forgot to ask, would I need more than one strap per scope?

[erick]

Even with the postage, you will currently do better buying from a US dealer. Just google the items and I'm sure a number of options will come up. Just work through the dealers to see who can supply all you want in one parcel with the best postage.

[[1ponders]]

try www.optcorp.com . Be careful though it is a very very very dangerous site ;)

[[1ponders]]

astrozap, thousand oaks, kendrick

http://www.optcorp.com/productList.aspx?uid=&pg=0&kw=heater&st=2

[[1ponders]]

http://www.optcorp.com/ProductList.aspx?uid=105-288-289-291
http://www.optcorp.com/ProductList.aspx?uid=105-288-289-450
http://www.optcorp.com/ProductList.aspx?uid=105-288-289-290

[Keshdogga]

Wow thanks for the links Paul :thumbsup::thumbsup: Says the Thousand Oak is on backorder :sadeyes: haha, but no hurry. Would the Kendrik Firefly range be noticably different to the Astrozap range ( http://www.optcorp.com/product.aspx?pid=105-288-289-291-6331 verses http://www.optcorp.com/product.aspx?pid=105-288-289-291-12513 )? Says they use a lower power. I'm going for cheap here as you may have guessed :lol: Looks like Optcorp is the way to go though =]

[Louwai]

I have all Kendrick heaters. I love them. :D

1 x Premier Ctrlr
1 x Digi-fire 10 ctrlr
2 x Digi-fire 7 ctrlrs
+ all up about 15 straps of varying sizes, + 2 x Telrad heaters & 3 x Laser pointer heaters.

All this is for 4 scopes.


If you decide to use Kendrick I'd suggest contacting Kendrick directly. They are a great help & will provide sound advise on what to use. http://www.kendrickastro.com/astro/index.html

[[1ponders]]

:thumbsup: @ Bryan

[acropolite]

I bought the Thousand Oaks controller from Star Optics a couple of months ago for $149, they had a special price at the time, it may be worth checking to see if the offer is still running.

I had one dew strap already, I bought 2 more from Bintel as it was hardly worth the trouble ordering from the US.

[jamespierce]

Dew Buster controllers for us, with some Kendrick and some Dew Not straps... it will be Dew Not from now on though.

[Liz]

Funny, none of us up here in Townsville have any dew control devices. :shrug:
We have terrible problems with dew, part and parcel of living in the tropics. Our scopes and books etc. get quite saturated, but we take it in our stride as part of our observing routine. Its always like it.
We stop every hour or so, cover everything up and chat for awile, then back to the scopes later on.
I actually bought a little $10 hairdryer from Repco recently, so may help a bit this year. :D
Lots of $$$ for those controllers and strips, yikes!! Who knows, may go down that path at some stage. ;)

[jamespierce]

Cheap compared to driving to the middle of nowhere to observe and having your session ended after 45min with dew on everything !

[Liz]

:lol: Yeah, I know, but the glass does clear after some chat, so we can start agin, and sometimes itsa nice break.

will look into it though, and the dew Not Dew seem a bit cheaper, but its the controllers that bring the cost right up.

[erick]

If you do electronics or has a mate that does, a controller can be built with a 12V speed controller circuit, a box to mount it in and some bits - for around $40-50 max.

This controller kit, at $18, is the cheapest I have found and drives a couple of heaters well:-

http://secure.oatleyelectronics.com//product_info.php?products_id=625&osCsid=27c5650086c88c3fa2045cf9826d fd13

[Liz]

that looks good Eric.

http://www.cloudynights.com/item.php?item_id=23

http://www.thousandoaksoptical.com/dew.html

http://www.dew-not.com/Order_Form.htm

What path are you going down Casey?

[Carlz]

between all the companies, are the connections all universal? say if i bought a kendrick controller, will the heater bands from bintel or thousand oaks still fit it?

[Rick Petrie]

Hi Carly
I have just fitted a Kendrick Dew Controller to my new scope.
Most of the dew straps, secondary heaters and Telrad dew heaters and others should have a standard RCA jack connection to the Dew Controller.
If you or Michael or someone you know is handy with soldering connections you can add whatever you like. Jaycar and other electronics stores have all sorts of fittings.
I have modified mine by this method as I had to adjust the lengths of cords to suit my scope and make tidy.
If you need help just call.
Cheers Rick:thumbsup:

[[1ponders]]

not a prob, certainly for Kendrick and TO

[Keshdogga]

Hey Liz. I've kinda taken to the idea of buying all the dew equipment from the same place in particular Optcorp. Controler's looking to be Thousand Oaks and Kendrik Firefly's are looking like the go for the heaters =] I was wondering if there was a 12V AC to DC converter available with the cigerette lighter attatchment too?

[erick]

Errr.... ? Explain than question a bit more, please? Just describe what you want to do. There'll be a solution.

[Keshdogga]

Haha sorry Maybe I asked for too many things in one. Forget i said AC to DC :lol:. Just a 12V power pack or something with a cigerette lighter socket. I don't actually own a car and all the Dew controllers look like the only source of power they get is from the car battery via the cigerette lighter socket. I was just hoping the controller would just plug into an AC power port but seeing as it doesn't appear that way I'd be quite stuck if I wanted to use the Dew system at home. Am i completely wrong here?

EDIT: Realised I didn't answer the question haha. I want to use the Dew control system with an AC power supply or a battery. Hope that answers it =]

[Carlz]

Thanks Rick :) I am looking at buying dew accessories for mine, but was worried about if i got different parts from different manufacturers that it wont fit/work. same with Michael, he got a controller and a couple of bands but now needs more so hes worried too. Thanks heaps for your help :)

[erick]

Yes, they all seem to come with a "cigarette lighter" plug to connect to a 12V DC source. That plug could be cut off and replaced with some other form of plug to connect to a 12V DC source, but the controller might be relying on a fuse in the "cigarette lighter" plug for over-current protection. Hopefully not, but that is worth investigating.

The question is - how much "power" are you going to need? Both measured as amps (A) to be drawn and, if you are going to use a battery to supply it, the total amp x hours (AHr) to be supplied.

A couple of small heater straps won't draw many A. See:-

http://www.dew-not.com/specifications.htm

The small ones typically draw no more than 0.5A at full blast.

So let's allow for a total current draw of 2A. Work out what yours will be. Playing safe would be to work out your maximum likely, then double it!

Most people would use a small sealed lead acid rechargeable battery, such as this 7.2Ahr one sold by Jaycar:-

http://www.jaycar.com.au/productView.asp?ID=SB2486&CATID=18&form=CAT&SUBCATID=250

You'll need a charger for it:-

http://www.jaycar.com.au/productView.asp?ID=MB3517&CATID=18&form=CAT&SUBCATID=250

And you will need a cable to connect it to the cigarette lighter plug:-

http://www.jaycar.com.au/productView.asp?ID=PP2007&keywords=cigarette+lighter&form=KEYWORD

You didn't think of all these extras, did you - this hobby is like that! Sigh!

You''l probably get a good 5-7 hours power from that battery running a couple of small heater straps at 1/2 to 3/4 power.

But you want to draw power from mains 240V AC? You need a power supply, mains operated, 12V DC out. In that case, you forget about AHr and concentrate on the A that the power supply can deliver.

There are neat ones that have a cigarette lighter socket already and supply more than enough power for your needs. Eg:-

http://www.jaycar.com.au/productView.asp?ID=MP3470&CATID=27&form=CAT&SUBCATID=381

BUT, you should be careful not to let it get wet outside - try to cover it with a box to keep dew off it.

[Keshdogga]

Thanks for the fantastic advice Eric, I think the Mains 240V to 12V DC Out ( http://www.jaycar.com.au/productView.asp?ID=MP3470&CATID=27&form=CAT&SUBCATID=381 ) looks like the way to go for me :thumbsup: It'd save buying in 3 parts as well. And yes "You didn't think of all these extras, did you - this hobby is like that! Sigh!" Truer words were never spoken :lol:

So just an overview:

Controller: Thousand Oaks
Straps: Kendrick Firefly Range (not sure on quantity) Need to buy straps for the SW ED80 and my Williams Optics 72mm
Power supply: http://www.jaycar.com.au/productView.asp?ID=MP3470&CATID=27&form=CAT&SUBCATID=381

[erick]

Let me just check with the more expert electronics guys out there. Do you all agree with the power supply I am recommending - for up to four heater straps - perhaps 2-3A max current draw from the dew controller?

And that it is kept under cover - doesn't get rained on, or excessive dew on it?