Dew prevention set up advice

[Guest Ryall]

Howdy all,

the time is near upon me when I shall have a fair amount of spare cash to spend on my anti dew kit for me 300p. I have a pretty good idea of what I need but I would welcome some advice in general. now please correct me if I'm wrong but I need to the following:

1 power supply - I was thinking of splashing some cash on http://www.telescopehouse.com/acatalog/Sky_Watcher_17Ah_Rechargeable_Power_Tank.html

but I have been given a car battery which I've been told should serve but I'm not the tech type and I wouldn't know how to connect it up to everything else. :S

1 Dew Controller - something along these lines http://www.telescopehouse.com/acatalog/Orion-Dew-Zapper-Pro-4-Channel-Dew-Prevention-System.html

it's only a four channel but unless I'm mistaken don't I need 5 channels? one for telrad, one for the 9x50 finder, one for the EP, and two for the secondary/primary mirrors? can you get splitters? or a another standalone controller?

The heater strips - This is where I'm most confused which ones do I shop for? I can see there are telrad specific ones and EP specific ones but Would appreciate some advice on which ones would best suit my 300p

extras - plastic box to store the power supply and extras to prevent them getting dewey? Anything else I might be forgetting?

Are these set ups relatively easy to rig up considering I've never done it before.

Thanks all,

Ryall

[BAZ]

Four channel dew controller.....How much?

Have a look at this one, it does the same job and is reliable. Dave also does a good back up service as well, just in case you have problems in the future.

http://www.firstligh...controller.html

Iam not sure which heaters would suit, but I have one Astrozap which works well.

Also a car battery will do, just make sure there is a fuse, 10 amps should do, in the main supply line. So if anything goes, it doesn't cook everything else. The only disadvantage is that you will need a trailing cable, which is dead easy to trip over, or pull out of stuff on the scope. But I did this for a good while, and it's way better than dew.

I'll keep an eye out for a battery for you, they are a bit sparse at the moment.

[Brantuk]

One of Baz's 40'ish ah PSU Batterys (free) will do the job for your dob. It'll run all your dew requirements all night and more - the badged power tanks are way overpriced - don't get one you'll be paying mostly for the name - and dew control will flatten them too quickly.

If you keep your eyepieces warm in your pocket for 10 mins before use you'll mostly find you don't need a dew band for them. I have one in use and one warming in my pocket all the time. The others stay well covered in a closed case (or in the tent/car) so they don't get dewed up.

You'll need a heater for the secondary cos it's exposed - also use a dew shield (DIY with cheap camping mat under a fiver) - and a heater strap for the finder or telrad (whichever you use). What you'll want for the primary is a fan on the back blowing ambient air over the mirror. A small 12v one usually does the trick - no heat band required.

I reckon you'd get away with a two channel controller for the finder and secondary - if you add in a telrad heat strip then a splitter should suffice. Wire a 12v fan direct to the battery. Martyn (Baz Snr) will advise on wiring any non standard connections - his 300P is well dew protected.

(crossed posts lol)

[BAZ]

Most of mine was already on the scope when I bought it. The controller is a home made one, by the guy who owned it. It has blown up a number of times, latterly at Kelling, but has been repaired again.

On the secondary there are two ceramic resistors attached by what I suspect is Araldite. I would use Silicon, it's easier to get off if the resistors fail.

I also made a Telrad heater with a smaller 3 Watt ceramic resistor, and this works a treat.

If you get a 2" eye piece heater, just hanging it on a 1.25" will do, it saves mucking about, I do, and don't generally have any problems.

If it's really dewy, no amount of heating will stop it. At EMS1, I had to give up in the end as dew had got between the lenses elements in the eyepiece, probably from my breath.

When I remember the password to my Photobucket account, I'll post a link so you can see what Iam banging on about.

[Daz Type-R]

Remember you may need 2 for the finder. 1 for the front of the finder and 1 for the eye end of the finder, cause I have a RACI, the eye end points upwards, dewed up like a good un.

For me, dew band and equipment wise,I have 2 x finder, 1 x Telrad, 1 x secondary, 1 x ep, all hooked up to a Kendrick dew control with 2 channels and 4 ports with 1 port running a splitter. All dew bands are Kendrick, and everything running off the world famous Baz battery.

[Guest Ryall]

Thanks for the advice fellows hopefully will be getting everything I need next week.

Edit: is this one of the heater strips I need? http://telescopehouse.com/acatalog/Kendrick_12___Dew_Heater_Strip.html

Ryall

Edited November 2, 2012 by Ryall

[Brantuk]

Yep that's the ones - the big brand ones are expensive - you can get cheaper but then like all things - quality and durability varies.

[catman161]

Remember you may need 2 for the finder. 1 for the front of the finder and 1 for the eye end of the finder, cause I have a RACI, the eye end points upwards, dewed up like a good un.

For me, dew band and equipment wise,I have 2 x finder, 1 x Telrad, 1 x secondary, 1 x ep, all hooked up to a Kendrick dew control with 2 channels and 4 ports with 1 port running a splitter. All dew bands are Kendrick, and everything running off the world famous Baz battery.

Hey daz,

I am looking into dew control for my 200P do you have any links to all the kit you use as I am at a loss as to what exactly I need. I also have RACI finder, only really use the Hyperion zoom with 2 inch adaptor. I imagine I'd need the same as you seeing as our setup I very similar. Any help would be much appreciated. Cheers

[Guest Ryall]

Another quick question: are all heater strips compatible with all dew controllers do they plug happily into one another? So if I got a hitecastro 4 channel dew controller would kendrick heater strips plug into it?

Ryall

[Daz Type-R]

Yes.

[Daz Type-R]

As quoted from FLO's website..........

"The Hitec-Astro four channel controller allows you to connect and control output to four individual heater strips (not included). Most heater strips (also known as tapes or pads) from all the major manufacturers are supported via standard phono type sockets."

[Guest Ryall]

Thanks.

[Guest MrsR]

This will all make sense to me one day soon I am sure !

[+RonC]

I've replaced my RCI finder with a RDF for the winter, less hassle!!

[Daz Type-R]

Hey daz,

I am looking into dew control for my 200P do you have any links to all the kit you use as I am at a loss as to what exactly I need. I also have RACI finder, only really use the Hyperion zoom with 2 inch adaptor. I imagine I'd need the same as you seeing as our setup I very similar. Any help would be much appreciated. Cheers

Hi Felix, sorry, just realised I never answered your question.

Felix.

I sourced all my dew stuff from Altair Astro, I have got.....

Kendrick 4 port 2 channel dew controller - controls the lot - wired up to a 38A/H baz battery - http://www.altairast...&cat=243&page=1

Kendrick premium 2" dew heater band - for the EP - http://www.altairast...&cat=243&page=1

Kendrick firefly 2" dew heater band - for the front of the finder - http://www.altairast...&cat=243&page=1

Kendrick firefly 0.965" heater band - for the ep of the finder - http://www.altairast...&cat=243&page=1

Kendrick firefly Telrad heater - heats the Telrad - http://www.altairast...75&cat=0&page=1

It is all a bit pricey - but I have never had to cut an observing session short yet with this lot - even when other people with dew stuff have!