20 May
2018
20 May
'18
11:24 p.m.
At 11:35 AM 20-05-2018, nokoa3116@gmail.com [op25-dev] wrote:
Do the tones not go like voice over radio.
Generally, no.
Is it like a code that the scanner then changes into a beep?
Yes. Tone frames encode a frequency index and a volume level. A receiver has to synthesize the indicated tone/volume for 20 ms per frame. Page 20 has a list of AMBE tones: <http://qsl.net/kb9mwr/projects/dv/codec/TIA-102.BABA-1%20%20P25%20Half%20Rate%20Vocoder%20Addendum%20.pdf> A slightly different list is found on page 58 here: <http://dvsinc.com/manuals/AMBE-2020_manual.pdf> IMBE tone frames are likely similar. --