Rob2160

Just my findings onRangetesting a JR 11X.

Please note this is not in any way a criticism of Futaba FASST or Spektrum, I have radios from both of these companies and they have all worked brilliantly and flawlessly for over 12 months and Thousands of flights..I have range tested Futaba and Spektrum equipment with great results that have inspired complete confidence in its use.. and a 100% reliability record confirms this.

But the 11X is something ELSE!...

I walk range test every new TX / RX or combo.. and any new installation in a Heli or Fixed wing..

Futaba FASST, Spektrum DSM2 / DSMX and JR DSMX all get well over 2000 meters clear line of sight (I don't bother checking further than that anymore..)

The reason for my range tests are not to test 2.4Ghz, but simply to test that any new TX / RX are actually not faulty out of the box before I fly with them...

(I picked up a faulty Spek RX this way and binned it without ever using it, thereby preventing a possible loss of a Helicopter)

But I digress..

Anyway, I also have a "Short version" of my range test, where I place the TX in my sunken loungeroom and walk around a large oval outside our house.

At the far extreme of the oval I am approximately 500 meters from the TX which is behind 3 brick walls and about 30 trees..

My Futaba FASST does not have reception at this point.. Neither does my Spektrum DX6i / DX8 with AR6200 and AR8000 combos...

The JR11X on the other hand has GREAT reception at that point with an AR8000 and also with an E-Flite Ultra Micro Beast.

These three videos confirm it..

Vid 1 - when I first bought the radio.. -

http://www.youtube.com/watch?v=2Gl6e25m9WU

Vid 2. Tonight with the UMX Beast (I only did another range test because I had opened the TX to adjust the spring tension on the sticks)

http://www.youtube.com/watch?v=rdT2lUY57Kk

Vid 3 Tonight Part 2.

http://www.youtube.com/watch?v=PcdmIvLWrig

A.T.

Transmitters are limited to the actual RF output permitted and so all generally have, within lineof sight,equal range.
The receiver is themain limiting factor, except with 2.4Ghz the type of signal generated has animpact, and during range tests, the power down RF level.
When comparing range tests, the power down output should be verified to be all 10% of full power or make allowancesaccordingly.
AFHSS by Hitec has proven to be the least effected by obstacles.

Good reading:
Range Test - Comparative Range Test data on multiple systems **
note that the JR/Spektrum systems, used in this test, has twice the TXRFoutput permitted in other countries so the result must be downgraded accordingly when read by those in Uk, Europe &Asia etc.
Range of Transmitter and Receiver
Receiver - Operating Range
Receiver - Operating Range - Full vs ParkFlyer vs Backyard.
Range Problem
and especially for those still using 27<75mhz.
Range Problem - Transmitter Antenna cleaning
<dl> <dt>1. 2.2KM Rx was inside the car
"Today I did a car ground range test. Full power, not range check dedicated mode. Very impressed ! 2.2km ground level !!!
And must stop the test because of the field iregularities, even if we choosed a very flat area, the car passed behind a small (2-3m) hill
that blocked the signal completelly. I guess that this system can do more than 4km in the air ! I wrote system and not Aurora,
because was a module mounted on a T9C.
Did I mentioned that the Rx was inside the car, placed in the back, having direct vision to the transmitter via the rear window? "

2. An interesting Video of a Heli model with full telemetry, sitting in ground effect and demonstrating a range of 4/10th's of a mile
or about 2,112 feet. Keep in mind this is with many large obstacles in the way! The 2.4GHz scenario has changed somewhat?
Range test using Segway & GPS

AFHSS - Power Down for Range Check is 1mw - tested to at least 1/4 mile.

and much more under
"Receiver Operating Range, Range Test & Range Problem Solving" at
Alan's Hobby, Model & RC FAQ Web Links

Alan T.
</dt></dl>

fizzwater2

My Feedback: (61)

at 2000 meters I would assume one isn't using the "power down" range test mode. To the original poster - is that a correct assumption?

Does anyone have the details on just how far down the power is on each brand's range test mode?

Also - if you're doing comparisons between brands on the power down mode, don't forget that the effective range is a square root function of the power ratio- not linear. For example, 2 times the power will only give you equivalent signal strength at 1.414x the distance. It takes 4X power to double the distance.

Rob2160

These range checks are in full power not power down mode.

I got much more than 2000 meters with 2.4Ghz when I tested to extreme ranges.. but I will never fly further than 500 meters in any conceivable situtation so if it still works at 2000 meters that is good enough for me..

Here are my very first range tests when I switched to 2.4. I was just curiious what range they would provide and was very impressed...


http://www.rcuniverse.com/forum/m_98...tm.htm#9829320

Rob2160

Thanks for the great info Alan, I look forward to reading those links shortly..