Portsdown 4 PTT not working?

[radiogareth]

I'm just putting together my 'mule' PD4 and want to include a PTT controlled closing relay contact....Just like I did on my first PD4.
But I'm getting nothing on Pin 40....
https://wiki.batc.org.uk/Portsdown_4_GPIO_Connections
Am I going mad.....its just got a 1k to a small switching transistor BC337 base which them does the harder work.
Don't think I need to 'enable' the facility., it should just go to TX. I will test later with a new RPi but from memory I have to date not used any of the GPIO since I installed it 6 months ago (was just a touch-screen in a box for Pluto and MT RX duties).

Gareth

[radiogareth]

So I tried a brand new RPI4.....PTT on pin 40 also does not work.....
I'm hoping its something simple.....
Gareth

[M5TXJ]

Hi Gareth

How long are you waiting? My Portsdown 4 with Pluto only keys the PTT relay (same setup as you except using a 2N7000) after approx 8 seconds.

73 Dave

[radiogareth]

Longer than that Dave.....very odd....
Gareth