RAM2 Altimeter

Willie Findlay - Dec 2009

This piece of kit actually belonged to George Whelan, but after he installed it in my Easy Pigeon one day, I played about with the data which gives an interesting insight to what’s happening up there.

The Recording Altimeter for Models is made by Soaring Circuits (US) and the RAM3 is the latest version. It can currently be purchased for $79 with details on their website www.soaringcircuits.com.

As you can see it is not particularly big and fits easily inside most models. It can either be powered from its own source or via the receiver. Without going through the actual workings of the gadget other than to say when switched on it zeros itself to ground level at your location and starts from there. It can be set to record height from 1 to 10 times per second and will do so for up to 18 hrs which is longer than the average flight.

Once your flying is done, the RAM3 connects to your computer and using Flightview software (available free from the website) the collected data is downloaded and converted into CSV format for export to spreadsheet software such as MS Excel. A graph of the flight can be produced as done for this flight (see opposite).

The graph shows that with my brushless set up the Easy Pigeon can climb at a rate of over 800 ft/min. I would say that was not bad and the 30 sec burn got me up to 429 ft. I obviously got straight into lift and thermalled up to 800 ft and managed to stooge about for around 4 minutes with minimal height loss (40 ft/min).

I then ran into two clear patches of heavy sink and fell out of the sky at 300 to 400 ft/min and despite a rally near the end, the Pigeon returned to terra firma after 12 odd minutes. What the graph shows, is that if I managed to stay in the better air and continued my descent around 40 ft/min I would have gained a flight of around 24 minutes. I suppose if a GPS plotter was used to overlay the RAM3 data, you would gain some knowledge as to the movement of the thermal, or in this case, where the thermal didn’t go, but where the plane did, and thus how to avoid the sink. I guess that’s what you call experience !!

RAM3 Specifications Size: 3/4" long x 5/8" wide x 3/8" high Weight: 21/4 grams Resolution: 1 foot Sample Rates: 1, 2, 5, or 10 samples/second Memory: Over 18 hours at the low rate Interface: Serial port - cable included. Power Supply: 3.1 to 15 volts Current Draw: 5 milliamps Operating Temperature: -4F to 140F (-20C to 60C)

Footnote - I later bought this piece of kit from George and it is now in the hands of Neil Davidson after I upgraded to the RC Altimier #2 Basic which includes a time/height limiter function and is now used in eSoaring competition. George And Norrie also use this kit and it was used in the Club Glider for the 2011 Club Trainer Competition.