Power antenna connection from Sony head unit

[Ed/L152]

I'm installing a new head unit in 90's Jeep Cherokee, replacing a tired Sony CDX-L400X with a Sony MEX-N5200BT.

The wiring is pretty straight forward, except for the vehicle's power antenna connection. Supplying 12v to this wire makes the antenna extend, and disconnecting it makes it retract. The old unit has a pinout that only energises when the tuner function was enabled, but whilst the new unit has a pin labelled "power antenna/power amplifier control (REM OUT)" it is 12v continuously whenever the unit is switched on regardless of input mode.

Is there a way to change the behaviour of this pinout so it is only energised when tuner is selected? I'm not using an external amplifier.

[Penelope Stopit]

If you can find a very clever radio man he might be able to do the job, there is no quick way
You could wire in a manual switch so as to use it only when the tuner is being used

[Blinkybill]

Unfortunately most manufacturers have dropped the separate ANT and Remote turn on outputs and combined them, only option really to use a switch inline as mentioned