ICOM 7400 (746PRO) TX DISABLE for SWL use.
 

I am wondering if there is a way to comlpete disable transmit functions on a
IC 7400 for SWL use with random wire antennas shared with other receiver.
I have already lowered the RF POWER to minimum, i have attacched a dummy
load to VHF connector, i have attached a wire antenna with impedance
tansformer (16:1) on ANT1 connector and obviously no Mike connection.
I have to be sure that radio does not go in TX with TRANSMIT button and / or
antenna tuning function.

There is some setting trick or hardware mod to obtain TX complete disable ?

Thanks !