VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Main > RV General Discussion/News
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 03-14-2017, 11:04 PM
j-red j-red is offline
 
Join Date: Dec 2015
Location: Lewes, DE
Posts: 268
Default DIY GSM/Cellular Preheater for <$125




Winter is almost over, but it was still <30f outside last Thursday. In order to get a flight in before work, I had to drive out to the airport at 5 AM to plug in the preheater, drive back home (it's only 10 minutes, but still....), and then return at 8 to fly. Leaving it on all the time is out of the question since it's a borrowed hanger and I don't want to push my luck. The alternative of letting the heater run all night the night before would still require a trip out the night before a flight to turn the heater on. If this were 12 months ago, this wouldn't be a problem. You see, a couple of years ago i stumbled across one of these babys: https://tinyurl.com/h4anbkq

Wake up, shoot it a text message, and it turns on any one of three recepticles. Worked great and cost pennies a month! Why am I not still using it, you ask? Because it's a 2g device and as of this past December, the nations 2g networks were largely dismantled it no longer gets service out at the field. TMobile still has their 2g network up for another year or two, and the device works here at home, being closer to town and all, but even here it's spotty. Another downside was that it was only rated for a total of 15a for all three outlets. I never had any problems with my small diy space-heater-turned-engine-preheater, but it was pushing the limits for sure.

Now that N94CR is flying again, it's painfully obvious that I need something similar that works on the current cell networks. Several are available marketed to airplane owners, but the cheapest is almost $300!
And then I found this: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
$115, and free prime shipping. Purchased it on Saturday and it showed up on Monday. I must have gotten the last one from Amazon because they're out now, but it's available from some import company as well...

Here's what you need to know:
1. You have to supply a sim card. It says ATT, but works perfectly fine with my old T-Mobile sim card. In fact, it works far better with the T Mobile around here... I actually purchased an ATT sim and tried it first, but it kept dropping the signal. Hasn't done that at all with the T Mobile.

2. The power requirements for the board are 12v dc, NOT 110v AC which is what you'll be switching with it. A google search for similar items reveals that there are units available with a built-in inverter (Search for something like "GSM-AUTO-AC"....) Instead of sending it back and ordering one of those, I just dug around in the closet for an old power cord for some appliance that used 12vdc and cut the pigtail off.

3. You have to read Chinese! Not really, but the instructions leave a lot to be desired. For instance, it tells you what the led's are assigned to, but not what their flashing patterns mean! There's also a button you have to push on the device before calling it to put your phone number on the "Whitelist" so that you can then control it. That isn't explained well.

4. The wiring diagram is pretty simple, but requires you to make a few pigtails for power input and output. I chopped up an old extension cord and picked up ends from the local big box store for $10 total. There are two 30amp relays inside, and they can be controlled individually to open and close, and even set to turn on for a certain time limit then off automatically.

5. The device is controlled by text messages which have to be formulated exactly perfectly and are quite obtuse. The good news is that there is a free App for iPhone and Android that makes this quite easy.

I got it built and tested tonight and it seems to be working great here at the house. The real test is how well it picks up a signal at the hanger. Verizon gets fine service out there, so it's promising. Included in the package was an external antenna with about 8' of cable to help locate it for best service. I'm hoping the short one that fits inside the box will be sufficient. With any luck, I'll be able to roll back over and snooze comfortably knowing my engine is warming peacefully as well.
__________________
Rebuilt RV-6A N94CR
RV-8 In Progress
2017 Dues Paid

Last edited by j-red : 03-15-2017 at 06:52 AM.
Reply With Quote
  #2  
Old 03-15-2017, 06:14 AM
PaigeHoffart PaigeHoffart is offline
 
Join Date: Jun 2005
Posts: 374
Default

I wouldn't recommend anyone wire a unit like that. The grounds appear to be clipped - they should be properly bonded. You are also switching the neutral conductor instead of the hot. Either error could lead to a shock hazzard.
Reply With Quote
  #3  
Old 03-15-2017, 06:54 AM
merlin3 merlin3 is offline
 
Join Date: Jul 2014
Location: ohio
Posts: 134
Default

They sell a unit on amazon that requires no wiring and works perfectly for like $40.i use it and it works great.
__________________
Justin
Rv-6, o360, whirlwind cs prop, old paint and panel
Rv-4,o-320,prince prop, mgl avionics screens - sold
Reply With Quote
  #4  
Old 03-15-2017, 06:58 AM
j-red j-red is offline
 
Join Date: Dec 2015
Location: Lewes, DE
Posts: 268
Default

Thanks for the input. Just so no-one gets led along in the wrong direction, I removed the wiring photo. After wiring an airplane, DC circuits are on the brain, I guess... The unit is switching the hot, not the neutral, but that's because I used the white wire for the hot and black for the neutral in the receptacles which must be opposite of standard protocol. I'll do what you suggest with the grounds.
__________________
Rebuilt RV-6A N94CR
RV-8 In Progress
2017 Dues Paid
Reply With Quote
  #5  
Old 03-15-2017, 06:59 AM
rleffler's Avatar
rleffler rleffler is online now
 
Join Date: Jun 2006
Location: Delaware, OH (KDLZ)
Posts: 3,986
Default

There are also 120v versions available from the Chinese manufacturer. I don't have the link handy at the moment, but if somebody wants it, please send me an email. (No PMs)
__________________
Bob Leffler
N410BL - RV10 Flying
http://mykitlog.com/rleffler
Reply With Quote
  #6  
Old 03-15-2017, 07:00 AM
j-red j-red is offline
 
Join Date: Dec 2015
Location: Lewes, DE
Posts: 268
Default

Merlin3,
Are you using the white and blue unit I linked to first? If so, I have one but can't use it here because it only works on the 2g network which doesn't exist where I'm located anymore. If that's not the one you have, please share!
__________________
Rebuilt RV-6A N94CR
RV-8 In Progress
2017 Dues Paid
Reply With Quote
  #7  
Old 03-15-2017, 07:03 AM
j-red j-red is offline
 
Join Date: Dec 2015
Location: Lewes, DE
Posts: 268
Default

rleffler,
I referenced those, and would definitely recommend that anyone making one of these go that route. I would have if I had realized the possibility when I bought this.
__________________
Rebuilt RV-6A N94CR
RV-8 In Progress
2017 Dues Paid
Reply With Quote
  #8  
Old 03-15-2017, 11:36 AM
merlin3 merlin3 is offline
 
Join Date: Jul 2014
Location: ohio
Posts: 134
Default

Yep i am using a similar unit and it still works on 2g here. Have you looked to see if they have one that will work on newer network?
__________________
Justin
Rv-6, o360, whirlwind cs prop, old paint and panel
Rv-4,o-320,prince prop, mgl avionics screens - sold
Reply With Quote
  #9  
Old 03-15-2017, 01:05 PM
RV6_flyer's Avatar
RV6_flyer RV6_flyer is offline
 
Join Date: Jan 2005
Location: NC25
Posts: 3,032
Default

Quote:
Originally Posted by merlin3 View Post
They sell a unit on amazon that requires no wiring and works perfectly for like $40.i use it and it works great.
Can you post a link to the unit?
__________________
Gary A. Sobek
NC25 RV-6
Flying
3,300+ hours
Where is N157GS
Building RV-8 S/N: 80012

To most people, the sky is the limit.
To those who love aviation, the sky is home.
Reply With Quote
  #10  
Old 03-15-2017, 07:00 PM
rv7charlie rv7charlie is offline
 
Join Date: May 2006
Location: Pocahontas MS
Posts: 3,196
Default

I never saw the diagram. But for those who don't know, in the A(lternating) C(urrent) world in the USA, black is hot, white is neutral, and green is ground. For 220V AC 'single phase' (which is really 2 phase), red is typically the 2nd hot wire. 3 phase 208 typically has blue for the 3rd phase hot. There are other variations, but AFAIK, black will never be ground.

https://www.google.com/webhp?sourcei...e+color+code&*
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 06:01 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.