http://www.windytan.com/2019/03/beeps-a ... radio.html
Todo esto aplicado a las frecuencias de PMR446 , pero por supuesto puede ser extendido a cualquier PMR analogico.
Muy curioso el squelch tail elimination tone (STE) basados en subtonos no standard 55, 62, and 260 Hz. Lo interesante es que yo conocia un sistema distinto usado para este mismo fin en sistemas basados en repetidores comerciales que cambian la fase del subtono PL al final de la transmisión para cerrar el audio muy rápidamente.
En el manual del tipico Baofeng UV-5R podemos encontrar mas información, y un subtono STE adicional.
Off Topic
35 - STE
Transceiver - Squelch Tail Elimination
This function is used eliminate squelch tail noise between UV-5Rs that are communicating directly (no repeater). Reception of a 55 Hz or 134.4 Hz tone burst mutes the audio long enough to prevent hearing any squelch tail noise.
Note: When enabled and T-DCS is set to OFF the radio sends a 55 Hz tone for about 1/4 second when the PTT key is released.
Note: When enabled and T-DCS is not set to OFF the radio sends a 134.4 Hz tone for about 1/4 second when the PTT key is released.
Note: Set to OFF before communicating through a repeater.
Note: Recommended setting is OFF
Transceiver - Squelch Tail Elimination
This function is used eliminate squelch tail noise between UV-5Rs that are communicating directly (no repeater). Reception of a 55 Hz or 134.4 Hz tone burst mutes the audio long enough to prevent hearing any squelch tail noise.
Note: When enabled and T-DCS is set to OFF the radio sends a 55 Hz tone for about 1/4 second when the PTT key is released.
Note: When enabled and T-DCS is not set to OFF the radio sends a 134.4 Hz tone for about 1/4 second when the PTT key is released.
Note: Set to OFF before communicating through a repeater.
Note: Recommended setting is OFF
Mas información: http://www.repeater-builder.com/micor/reverseburst.html