I have an Eclipse 7 Q-PCM, software version 12

Most people seem to recommend that the crystal or RF module is removed when a trainer cable or a PC interface is connected to the transmitter. I've heard that some transmitters automatically disable the RF module when a PC interface or the student end of a trainer cable is connected.

If I have to remove the RF module every time I use the simulator, I'm afraid the connectors will fit rather loosely after a while. The best would be to use the Tx as it is (just connect the interface cable).

When I connect the PC interface (with the antenna collapsed and the RF module and crystal IN the Tx), the indicated voltage goes up by .2 to .3 volts. I also got 6-7 hours operating time from one charge. The way I see it this indicates that the RF module is off. Higher voltage means that the load went down. 6-7 hours op. time is impossible if the Tx is transmitting. If I switch on both the Tx and Rx and then connect the PC interface, the servos quit responding as if I switched off the Tx. This confirms that the Tx isn't transmitting when the PC interface is connected.

But; I'd like to be on the safe side and ask.

Tell me the truth

I always unplug me module to be on the safe side. You can do this thousands of times with no problemss.

Mike.

...but is there a circuit that switches off the RF components when the interface is connected, or isn't there?

If there is such a circuit, unplugging the module is totally unnecessary.
If there isn't, what causes my Tx (both Flash 5X and Eclipse 7) to stop transmitting when I connect the interface? Is something wrong?

No.

Hitec Eclipse 7 switches RF off when pins 4 and 5 of the student connector are connected together
(short-circuit). Hence no need to remove the RF module, except on or near the flying field, as an additional security measure, because removing the connector will immediately generate the RF,
maybe provoking a plane crash.
We use this with an active cable to PC when RF is not needed (looking at transmitter settings in real time by connecting to a PC, running a simulator like FMS), and we leave it open if we record a real flight on a portable PC.
Refer to (simple)PCM under NEWS/ARTICLES at
[link]http://www.jdm-nivelles.be[/link]
for more info on the active cable and the softwares we use. All FREEWARE.
Philippe