IIRC, RS-232 standard allows logical "1" to be anywhere between -3 and -15...-20 volts, and logical "0" from +3 to +15...+20 volts.VK3KYY wrote: ↑Mon Dec 19, 2022 8:29 amI had not previously come across 10V RS232.
I have seen 20V RS232 using native voltages, but that was a long time ago..
The problem with the 10V signals from the module I bought was that the signal is inverted as well as being higher voltage.
If it wasn't inverted a simple voltage divider would have fixed the problem.
However 3.3V or 5V signals down a couple of meters of wire seems to be OK
Inverted signal is not a big deal - use a small BJT or MOSFET to invert it once again. One extra part compared to a divider.
Or if you have access to GPSr PCB - you may just remove or bypass the TTL-RS232 level converter. Most likely it's max3232 or similar IC.