But I finally managed to find a way to install a screw driver antenna on window by using a suction cup lifter.
ATAS-120 on window with suction cup lifter
ATAS-120 is tilted so that the end is extending away from the roof.
With this configuration, I can operate on 7 MHz and higher bands by just touching a TUNE button on FT-991.
ATAS-120 can also transmit and receive on 144 MHz & 430 MHz bands. (ground plane radials are attached)
According to the specification, this suction cup lifter boasts a lifting capability of 50 kg (110 lbs), and so I believe the weight of ATAS-120 is ok.
