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#1 Nathan Schmoekel Jan 14, 2010 09:10 AM

Altimeter links
I keep seeing the question........What altimeter should I get? /or/ What altimeter do you use?

A forum wide search of the word Altimeter used to result in no directly informational threads, just random posts here and there which required too much reading.

This thread changed that and aims to make it easier to find information on the subject of altimeters.

Please post links and any personal experiance you may have with altimeters, or related acessories. I will try to keep editing this first post with those links so the info will be easier to find and fumble through. Lets try to limit the conversation and not tangent too far into complex features of data logging systems which contain altimeters, just provide a link and a bit of basic info and or your experiences (good or bad). Thanks

Links: If you find outdated information here please post or PM me so I can update it.

Winged Shadow Systems- How high Altimeter, http://www.wingedshadow.com/products.html
Related Posts- #2, 48 Winged Shadow Systems is no longer in business, but the web site is still up for informational reference.

Soaring Circuts- RAM 3, http://www.soaringcircuits.com/
Related Posts- #3, 28-33

Magellen, http://www.magtechinc.net/index.htm
Related Posts- #9

Zlog, http://www.hexpertsystems.com/zlog/
Related Posts- #5

Eagle Tree Systems, http://www.eagletreesystems.com/inde...&product_id=60
Related Posts- #6-8

LoLo, http://www.lomcovak.cz/lolo/lolo.html
Related Posts- #23

Altimax Altimeter, http://mysite.verizon.net/resrqa3z/airtek/id66.html

Open Altimeter, www.openaltimeter.org
Open Altimeter- RC Groups Thread, http://www.rcgroups.com/forums/showthread.php?t=1342829
Related Posts- #40-46

Other interesting posibilities

Post# 13 - DYI assistance
Post# 22 - Hitec Aurora telemetric GPS system. http://www.hitecrcd.com/products/new...ic-system.html
Post# 25 - Variometer http://www.pitlab.com/skyassistant-variometer.html

Related Threads
http://www.rcgroups.com/forums/showthread.php?t=1612305 This thread addresses altimeter accuracy...a who's who of experts is in on the discussion.

#2 ScottLister Jan 14, 2010 09:23 AM

I did a mini review of the How High altimeter when I reviewed the arrow pro. You can check it out here: http://www.rcgroups.com/forums/showt...rrow+pro+build


#3 bjue Jan 14, 2010 09:47 AM

I was just starting to look at these too, looking forward to what others have to say. There's also the Soaring Circuits RAM3 http://www.soaringcircuits.com. It's twice the cost of the how high and I don't think it gives the immediate readout, but it will store 18+ hours of data sampling at the 1 sample/sec, and you can select up to 10 samples/sec. You have to offload the data into a pc, but you get get much more than just your peak altitude, you can get your whole flight or your whole flying day recorded, and graphed and you can determine sink rates and other info.


#4 Ralph Weaver Jan 14, 2010 09:52 AM

I have:

RAM 3 which works well and is very small. http://www.soaringcircuits.com/
RC Altimeter Basic, a bit larger but includes read out and electric height limiter. http://www.magtechinc.net/RCAltimeter.htm
Zlog, nice also with display. http://www.hexpertsystems.com/zlog/

I also have a SkyTraceGPS http://www.magtechinc.net/SkyTraceGPS.htm
and a SkyAssitant http://www.magtechinc.net/SkyAssistant.htm but these are a bit too big for HL use.

#5 Guz Jan 14, 2010 11:19 AM

I can relate some info on the Zlog in DLG's.

I have a MOD4 Zlog, which has a micro USB connector soldered on the board for downloading data. It is a nice system. But it looks like they are no longer offering the MOD4, but have gone back to the MOD3, which requires a separate USB dongle to interface to download data (sold separately).

The thing that I have found for using the Zlog to evaluate DLG launch height, is to change the sampling rate. The unit is set by default to sample once ever second, to slow to find your launch height. By increasing the sampling rate to "100 milliseconds" (0.1 sec) either by the software, or pressing the buttons on the unit, you can evaluate your launch height more accurately.

The unit is nice that you can put it in your plane, start logging, and do a set of launches (~27 min till the memory buffer fills up at 0.1 sec sampling rate), take a break, download the data (a laptop is needed, or a small netbook) and then look at how you did.

One nice feature of the software is that with a press of the button after you download the data, it will correct drift. That is, since the unit works off of barometric pressure, during the course of gathering data the general barometric pressure may either increase or decrease and it will skew the data either up or down. So I generally land the plane on the ground, let it sit for a second or two between launches, so when I have the data loaded on my laptop the "fix drift" will be more accurate.

If I'm not concerned about looking at my launch height but want to see how high I can go in thermals, I will change the sampling rate back to 1 second (~4.5 hours of data in the memory buffer).

If you want to quickly see your maximum height you don't have download the data to your computer. Just stop recording, and press a button and the maximum altitude will be displayed on the LCD screen.

The Zlog does get it's power from the receiver. Now if you don't have an open servo channel on your receiver, not to worry (example: you use a 4 channel Rx). It is a pass through device. That is, you disconnect a servo, plug the Zlog into that channel on your Rx, then plug the servo into the Zlog and the servo functions as normal.

One thing I have found, is DON'T use the Zlog as a pass through for your battery to the Rx. It can't handle the current for some reason (even though the specs says it can) and it cut power in and out randomly. At least mine has this issue, it may have been corrected in newer versions.

The one down side of the Zlog is that is big. It won't fit in some DLG's (the Stobel for example).

I've been having fun lately with my fellow pilots, when we all catch a good thermal and have generally maxed out. I will yell "OK, everyone, take a guess at how high my plane is!" Everyone yells out what they think (example: 5-6 hundred feet). Then after I land I look up what the altimeter says and let everyone know. It's amazing how far off we can be (myself included). So far CptSnoopy has been the most accurate.

#6 tai626 Jan 14, 2010 11:50 AM

1 Attachment(s)
Stand alone altimeter from Eagletree:


Weight = 4g.

#7 tai626 Jan 14, 2010 11:57 AM

This one has the real time read out:


Yes, it is more complex. and weight more: 28g. The weight is ok. To throw high you need a ballast anyway.

The Hitec Aurora 9 will have the similar feature for later this year.


#8 flyingj Jan 14, 2010 12:15 PM

The only issue I didn't like with the Eaglstree 4g is the 4' resolution.

#9 bjue Jan 14, 2010 12:35 PM


Originally Posted by Ralph Weaver (Post 14068805)
I have:

RAM 3 which works well and is very small. http://www.soaringcircuits.com/
RC Altimeter Basic, a bit larger but includes read out and electric height limiter. http://www.magtechinc.net/RCAltimeter.htm
Zlog, nice also with display. http://www.hexpertsystems.com/zlog/

I also have a SkyTraceGPS http://www.magtechinc.net/SkyTraceGPS.htm
and a SkyAssitant http://www.magtechinc.net/SkyAssistant.htm but these are a bit too big for HL use.

The SkyTrace is a very cool device, see here http://www.bayrc.com/boards/viewtopic.php?t=5026

Also, down toward the bottom of this page http://www.bayrc.com/boards/viewtopi...=4925&start=45

#10 bbbp Jan 14, 2010 05:09 PM

Altimeter Software
I like the RAM3 software, with the start and end markers to determine the time of any single throw. And the Zero Start / End do work well for getting the plots straightened out for printing.

The ZLOG unit fits in my Lighthawk I cargo bay and the readout is nice for seeing in the field your altitude.

On my larger sailplane the SkyTraceGPS is the most fun, 3d KML files shows exactly whre your flight went, overlaying Google Earth photos and terrain! It needs a faster sample rate and I usually lose lock for a couple of seconds in steeper turns.

I had to mount it outside the fuselage (too much carbon). I built a bubble pod from some plastic packing material. Heated it up and stretched it over the unit & plane canopy, and taped it down.

On another aside, I have excellent service on my RAM3 from Randy Brust. I tried to download my battery instead of the Ram3 and fried the cable. It was fixed and returned for the price of postage!

Bob P

#11 Noel Robbins Jan 15, 2010 12:53 AM

Thanks Nathan for starting up this thread. -Noel R.

#12 Nathan Schmoekel Jan 15, 2010 12:09 PM

Thanks all for contributing. ...And your welcome Noel. (His post on the Predator II thread inspired me to start typing).

I know there can't be many more altimeters out there besides what has been posted so far, but I'd like to get this thread over 20 (usefull) posts.

The thread links that bjue provided in post #9 are definetly in allignment with the intentions of this thread. Those are the kinds of things people might like to see before they decide to buy one or another brand. Links to reviews and other usefull comentary will also be cataloged into POST#1.

I would like to see more personal accounts from people who are using altimeters. Problems you may have had, features you really like, maybe some of you had one kind and changed to another to solve a personal need?? Stuff like that...

Keep it comming, but also keep it focused....Thanks!!


#13 Stuart B Jan 15, 2010 01:42 PM

if you want to write your own software to create one (there is a good start for the software already written supplied with it) is this

http://www.ti-estore.com/merchant2/m...30-Chronos-915 although even with the ineternals only, might be too big for dlg.

I have one I want to play with (when I pull my thumb out)


#14 frostyspeed Jun 05, 2010 05:13 PM


Originally Posted by tai626 (Post 14069652)
Stand alone altimeter from Eagletree:


Weight = 4g.

Do you just plug this into your rx? Is there a way to download to a pc or does it only show you peak alt?

#15 Nathan Schmoekel Jun 05, 2010 06:18 PM

My understanding is that the Eagle Tree stand alone unit only gives the peak readings unless they are also attatched (in flight) to the E-logger. In other words the stand alone altimiter by itself has no way to memorize all flight data, just the peak.

For DLG the unit is only usefull for launch height data, provided you are launching and then landing without catching a better ride....

If you are looking to record full flight data the Ram-3, Magelan, and Z-Log are the choices. Check to be sure, but I think most of those also give some indication of peak altitude with out a PC.

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