One of the most important steps to perform when you have new tx/rx equipment is to do a range check.  Range checks verify that the radio equipment is working properly, and help prevent costly crashes.

This thread will discuss ways of properly doing range checks, not only on PPM/PCM systems, but also on 2.4 systems.

What are the steps involved in a range check ?

The usual steps involved in the range check of a normal PPM/PCM system are :

1) Make sure the engine is off for nitro models, and the motor is preferablt disconnected for electrics.  This prevents the models from taking off, in case of a loss of signal.

2) Make sure that both the tx and rx are powered on.

3) Collapse the antenna fully, and walk away from the model, moving a control surface (rudder is a good choice).

4) You should be able to walk 100feet without feeling any glitches on the control surface movement.

In the case of 2.4Ghz systems, since the antenna is not a collapsible type, the range check is done using a "low power mode" (on supported radios).

Quote from: anwar on March 24, 2009, 12:30:52 AM
2) Make sure that both the tx and rx are powered on.

3) Collapse the antenna fully, and walk away from the model, moving a control surface (rudder is a good choice).

Never keep your PPM TX ON with the antenna collapsed for a long time. For range check, do not exceed the time of ~30 secs where TX is ON and antenna collapsed. I would walk with the TX OFF and then turn ON at the spot where I want to do range check and keep the TX ON/Antenna collapsed time as mimimum as possible.

All this is because the TX pumps a good amount of power into the antenna. By design, the antenna is matched to the internal circuit when it is fully extended. If it is collapsed then the part of the power returns back to the internal circuitry and damages/degrades the components. Its just like throwing a ball against a wall...  In due course of time, you will end up with a dead TX.

Modern TX have inbuilt circuits to avoid this... but these protection circuits take the toll instead of the costly RF amp components... In any case, there is a risk of damage to the TX.

-Ismail

On my Spektrum DX6i, there is a menu item for range check.  Once that mode is selected, then by pulling in the trainer switch, i can go onto low power mode.  The Rx should work fine for 30 feet atleast on low power mode with the trainer switch pulled in.

Chan

in futaba 2.4ghz system, there is a power down option........ we use that option to check the range...... 

Religiously do the range checks with each model every time you take it out to field before flying.
Will save you tons of possible trouble