It must be replied right after it has been received the first time.
It does not matter if this happens a bit later, even a second later.
Thanx to Hans Wigger for providing recording from his B-Netz tester to
figure this out.
Connect to the oscillator of the transmitter - good girl!
You need to enable pre emphasis in this case.
Connect to the discriminator of the receiver - good boy!
You need to enable de emphasis in this case.
-W <file.wav> writes a wave file of received audio
-R <file.wav> reads a wave file to feed into decoder
This way you can record a phone and later debug without a phone
and radio equipment.
Andreas Eversberg