Kendrick dew control

[Granada]

I've been recommended Kendrick controller and straps by a number of people, however their gear is quite pricey. Wondering whether it's really worth the price and if I should just bite the bullet or if there are cheaper alternatives that people have found to be just as good?

[xelasnave]

I was in the same boat.
Things I thought of doing.
Buy a strip on EBay.. cheap but I know nothing more but no controller.
Use a Peltier device the heat the area...no controller...I HAVE ONE AND IF YOU TAKE OFF THE FINS YOU HAVE THE ACTUAL UNIT sorry I hit caps and I think you could merely tape it on ota somehow.
I purchased a small windscreen heater/ fan for $45 that blows heated air from below the scope and it seems to work...but I have bought a strap from Bintel but no controller and will switch it off and on...until I get sick of it and buy the controller as well...I do wonder how many amps will be needed however.
Alex

[Xeteth]

I have very little experience with any dew control yet, but I was going to purchase a Kendrick set once I get my new telescope. It is pricey, but from what I hear they are the premier brand to go with. They have a 'premier' device they are currently developing which should release in the upcoming months, it has dew control, wifi, a bunch of handy features and also has a built in stepper controller. I'll be waiting for them to release it then I'm just going to bite the bullet and purchase that.

They also have a powered 12v USB hub which I will pair with it - all together this should be a really neat solution to dew control, focus control and help with cable management.

[peter_4059]

I've had the original Kendrick Premier controller for many years and it works well. The power cable became brittle over time and I had to open up the controller to fix that but not a big deal. The thing I like about it is it measures ambient temp and humidity and then controls heater output to maintain a fixed heater margin above the dew point so you never have to adjust anything and it only applies heat when it is required. Mine also has a pc interface to allow settings to be changed from the computer however I have found the serial coms a bit flakey more recently - not sure if that is Wind 10 update related.

With what I have learned about Arduino more recently, it wouldn't be difficult to build a similar dew controller at a fraction of the cost however I still use the Kendrick one while it is working.

[Granada]

Thanks everyone. I think Kendrick sounds like a good idea, although I might have to settle for one of the cheaper models. Sounds like a good investment

[xelasnave]

You sold me I will get one. Thanks.
The little heater fan also seems to keep the scope drier so I will keep it in the mix and observe it's effects on that annoying dew on the gear.
Alex

[Startrek]

I use a variety of Kendrick dew straps with an Orion 4 channel Dew Zapper for my 3 rigs
6” f6 newt on an EQ6-R Mount
8” f5 newt on an EQ6-R Mount
12” goto dob
Never had any issue with dew for 2 years since I’ve had them
Oh and I have 2 locations , Sydney and South Coast NSW
Thumbs up for Kendrick a great Canadian astro company ( not cheap but do the job properly)

[Sunfish]

I have one of the small Kendrick two channel four port controllers I purchased from a fellow IIS member along with a strap and it is a great thing. Very compact and Velcro holds it on the mount and saves dew , mould and and a little refocusing.

I looked at making my own strap with resistance wire and a little sewing which would be interesting. The controller I have measured at a voltage cut down to 6 v or so for each channel and a total maximum of 7 amp I think although it is rated to much more and cuts out on low voltage input .

I suppose a strap could be powered by my drill battery USB port at 5v. ? I also have a 100 mm computer CPU fan with a speaker cable plug on the end which I can plug into the controller.

[ChrisV]

You could build my one!

It's been going strong since 2016. An Arduino and a few bits and pieces. Feedback control of heater, so you just start it up and never have to think about it. I've got some updates which I should upload - includes a PC interface if you are so inclined. I use nichrome wire for heaters.

http://www.iceinspace.com.au/forum/showthread.php?t=144679
https://github.com/ChrisV77/TelescopeDewHeaterController

[Merlin66]

Granada,
The Kendrick controller works very well. I use it to control the heater on my C11.
Ray,
Yes, easy to make a wire heater, sewn between two strips of velcro.
I made one for my 12" Meade...
Only difficulty is making off the ends of the wire to connect the power lead.