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I have been looking on line, and a lot of people recommend the dew buster... But its pretty pricey. Has anyone had experience with the AstroZap dual channel controller? Will that work fine?
Here's the link:
There's also the thousands oaks one, same question:
I was thinking that controller with these heating bands:
OTA -
guidescope -
Also, I read that you shouldn't power the dew heaters with the same battery you use for your scope... Should I have 2 separate batteries, one for mount/laptop/DSLR, and one for dew controls?
Thanks guys!
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
I'm using the Kendrick standard dual channel. I think it's their most basic model.
Most modern dew heaters use a pulse-width-modulator to manage the power. This is basically a square wave generator with a varying duty cycle. (imagine a really fast repeating on-off switch where you vary the ON time from zero to 100 percent)
This method of power control is easy to implement and is low cost. But it can cause electrical noise that may interfere with other equipment. This is why it is sometimes recommended to run off two batteries. I have actually seen this very problem on an old dew controller I had, but I forget what brand it was. In my case, it would cause the hand controller to randomly fail on one of my mounts.
The Kendrick controller says it is "RFI (radio frequency interference) free. A critical feature for astro imagers!", but right after that it also says "Pulse Width Modulation duty cycle control." too. So my guess is that they are using a PWM circuit to manage the power output but they have put a filter on it to reduce or eliminate the electrical noise coming off the PWM circuit. Whatever they did, it works. I can run mine on the same battery as the rest of the gear and there are no problems.
Having said that, I do actually run it on a separate battery anyway. This is to distribute the power draw among my two batteries. The dew controller can take a lot of juice so it and the mount share a battery. All the rest, which is the cooled camera, laptop and USB hub go on the other battery. This seems to work and most nights both batteries draw down at pretty close to the same rate.
If you get a Kendrick, or another like it, you might want to check to see if it has a minimum voltage level. The Kendrick will automatically shut off when the battery drops below 11.6 volts. This is to preserve the battery since deep cycle batteries can be damaged if drawn down too low. This caught me out a couple of times and the controller would shut off during the night without me realizing it. Then the dew would start forming on the optics and I'd usually not even notice until I was done imaging.
This safety feature caused a few lost hours for sure and was a major factor in me deciding to go with two batteries. Which was costly at first but worked out really well in the end since I've not damaged them yet and I've been using them for probably five years now. The other downside is that I have to lug around two big batteries and contend with two separate wiring systems. That took some extra time and money as well. But now that it's done, it's pretty easy to deal with.
Thanks for the info, Dave! That is very helpful information. I was looking at the Kendrick one too... I forgot why I narrowed it down to AstroZap and Thousand Oaks... It might've just been because those are on Amazon lol
Are you using the dual channel controller from Kendrick?
"Unit automatically turns off if voltage drops below 11.1v. At 11.25v the green LED begins flashing indicating unit will turn off in approximately 30-60 minutes." That's for the Thousand Oaks controller. I couldn't find that info on the AstroZap one... But they state on their website it shouldn't be used on anything other than 12 volts.
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
JayTee wrote: ↑Sat Sep 28, 2019 7:37 am
I have a plan for a DIY dew heater if you are interested. Very inexpensive to build and no need for an advanced electronics degree. Let me know.
Cheers,
JT
I would definitely appreciate a look! Thanks, JayTee.
I'm really bad with the mechanical stuff, but I welcome any opportunity to save some money lol
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
So the build involves cutting 3 wires then making two connections by twisting wires together, then soldering those two twists (easy to do). And then a lot of duct tape!
That's pretty much it. I'll post it later today.
JayTee wrote: ↑Sat Sep 28, 2019 7:49 am
So the build involves cutting 3 wires then making two connections by twisting wires together, then soldering those two twists (easy to do). And then a lot of duct tape!
That's pretty much it. I'll post it later today.
Cheers,
JT
I've never soldered anything in my life (nor have I cut any wires, for that matter lol), but I'm willing to give it a shot, as like as what I need to do everything is relatively inexpensive. Thanks, JT!
Thanks for sharing, Dritter. I will look into that one, too.
As always, y'all are very helpful and informative. I appreciate it.
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
I’ve got DIY dew heaters on my main scope and guide scope. Sounds like yours are also nichrome wire (and duct tape).
Cost including the LED dimmer is near nothing. Actually, the dew heaters are probably the most trouble free part of my setup!
Thanks,
Jim
Jim
Scopes: Explore Scientific ED102 APO, Sharpstar 61 EDPH II APO, Samyang 135 F2 (still on the Nikon).
Mount: Skywatcher HEQ5 Pro with Rowan Belt Mod
Stuff: ASI EAF Focus Motor (x2), Orion 50mm Guide Scope, ZWO 30 mm Guide Scope, ASI 220mm min, ASI 120mm mini, Stellarview 0.8 FR/FF, Sharpstar 0.8 FR/FF, Mele Overloock 3C.
Camera/Filters/Software: ASI 533 mc pro, ASI 120mm mini, Orion SSAG, IDAS LPS D-1, Optolong L-Enhance, ZWO UV/IR Cut, N.I.N.A., Green Swamp Server, PHD2, Adobe Photoshop CC, Pixinsight.
Dog and best bud: Jack
Sky: Bortle 6-7
My Astrobin: https://www.astrobin.com/users/Juno16/
I use the Kendrick dual channel as well with their premium heaters but do use a Thousand Oaks 4 channel controller as well.
For longevity and even heat Kendrick is about as good as it gets.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885 EQ: TAL MT-1, Vixen SXP, AXJ, AXD Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102 Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror Eyepieces: Antares to Zeiss The only culture I have is from yogurt My day was going well until... people
But I just plug it directly into the 12V bench supply without a controller. It never gets even slightly warm even though it pulls current. So if I see any misting up of my corrector plate I blow some warm air down the dew shield using a 12V hairdrier!
Awesome thanks JT! I'm nervous lol, but it looks simple enough. Probably a silly question, but this will be fine to put over the ED80 right? I'v seen people put makeshift dew shield over the ED80, but I have not seen a dew heater like this yet.
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
I try to save money on some astro stuff so that I can put some of my limited budget into more important things. Not that dew isn't important. It is definitely a show stopper!
I basically did the same thing as you, except I wrapped the nichrome wire lenthwise. Seriously, the rig works great and really takes only a few minutes to build. Plus, its super cheap.
I even made a spare in case of failure.
Thanks,
Jim
Jim
Scopes: Explore Scientific ED102 APO, Sharpstar 61 EDPH II APO, Samyang 135 F2 (still on the Nikon).
Mount: Skywatcher HEQ5 Pro with Rowan Belt Mod
Stuff: ASI EAF Focus Motor (x2), Orion 50mm Guide Scope, ZWO 30 mm Guide Scope, ASI 220mm min, ASI 120mm mini, Stellarview 0.8 FR/FF, Sharpstar 0.8 FR/FF, Mele Overloock 3C.
Camera/Filters/Software: ASI 533 mc pro, ASI 120mm mini, Orion SSAG, IDAS LPS D-1, Optolong L-Enhance, ZWO UV/IR Cut, N.I.N.A., Green Swamp Server, PHD2, Adobe Photoshop CC, Pixinsight.
Dog and best bud: Jack
Sky: Bortle 6-7
My Astrobin: https://www.astrobin.com/users/Juno16/
The dew heater in the plan is for my C11 which is why it is so long. For my C11 I used 60" of nichrome wire laid out in an "S" on the duct tape. For your 80mm I would use 3 complete wraps using 33" of nichrome wire (I believe the circumference or your 80mm OTA is roughly 11"). This would only take slightly more than half the voltage I use to prevent dew. For my system, I use roughly 9V through the PWM and I use a separate power supply (a 17Ah) jump start battery from Harbor Freight.
I have an old Orion Dew Zapper I bought off of eBay a few years ago. It's a simple plug-in device with no adjustments. The heat tape is held in place with a stretch nylon band. I'm really glad I had it last night...
Gordon
Scopes: Meade LX10 8" SCT, Explore Scientific AR102 Refractor on ES Twilight 1 Mount, Oberwerks 15X70 Binos, Nikon Action Extreme 10X50 Binos.
Eyepieces: ES 68* 24mm, ES 68* 20mm, ES 82* 11mm, ES 82* 8.8mm
Observing: Messier Objects--110/110, H1 Objects-- 400/400. Hundreds of additional NGC Objects. Significant Comets: Kohoutek, West, Halley, Hyakatake, Hale-Bopp, McNair, Neowise. Transits of Mercury and Venus.
2017 Total Solar Eclipse
JayTee wrote: ↑Sat Sep 28, 2019 11:06 pm
Hi James,
The dew heater in the plan is for my C11 which is why it is so long. For my C11 I used 60" of nichrome wire laid out in an "S" on the duct tape. For your 80mm I would use 3 complete wraps using 33" of nichrome wire (I believe the circumference or your 80mm OTA is roughly 11"). This would only take slightly more than half the voltage I use to prevent dew. For my system, I use roughly 9V through the PWM and I use a separate power supply (a 17Ah) jump start battery from Harbor Freight.
Cheers,
JT
Ah cool that makes sense! You use the 17Ah jump starter just for your dew heater, right? how long does that last you?
I'm curious: Do you use a deep cycle battery for your other equipment?
-James W.
Telescope:Explore Scientific 80mm FCD100 Triplet APO Refractor Mount:EQ6-RPro Cameras:ZWO ASI1600mm Pro (Cooled) | Canon DSLR EOS T7i Auto-guiding:ZWO ASI120mm-Mini + Astromania 50mm Guidescope
You use the 17Ah jump starter just for your dew heater, right? how long does that last you?
I've only needed it to work around 4 hours per night. There was one weekend where I had to use it both nights and the battery lasted all the way through the weekend.
I'm curious: Do you use a deep cycle battery for your other equipment?
Yes, I do have a deep cycle marine battery as the source of my power for my power station. But I still use the separate stand alone battery for the dew heater.