[nos-bbs] More on these RTS based PTT circuits everywhere

[Boudewijn (Bob) Tenty]

I have the RTS line connected via an resistor to the anode of the diode inside the Optocoupler, with  the cathode in there
connected to ground. In rest RTS is negative.  When I activate PTT in FLdigi, WSJTX, etc. RTS goes positive and Optocoupler
pulls PTT to ground and operates TX as you said. If I quite my programs like the above, RTS just remains negative, no tx is triggered here
after that.  No problem here.

> converts negative logic to positive ...

That is the only thing I shouldn't  have said as RTS is using NRZ.

Bob VE3TOK

On 2021-01-31 21:25, M Langelaar wrote:
> Hey Bob,
>
> > In those other 100s of circuits the Optocoupler already
> > converts negative logic to positive ...
>
> How ? why then when I quite most of my programs like winmor,
> or WinRPR, optocoupler is energized and PTT is taken to ground
> and TX is triggered, unless I'm missing something really obvious :(
>
> Maiko
>
-- 

When you change the way you look at things, the things you look at change 

Max Planck