Originally Posted by
Payalneg
No problems with rc4 hybrid transponders.
Some loop amplifier for Howards decoder. Best work with 10m loop

OK thanks you Payalneg, it's perfect your loop amplifier it's an alternative for the transistors schema......
For the old amb personnal transponder, Howard looks 24 bits after the valid signal; and he valid the transponder when the 24 bits is repeat 3 times, but how you detect an RC4 tranponder ?