User's Guide

18
Radio Firmware Features
The receiving radio will mute its speaker before loss of a carrier is
detected, upon receiving the TPL reverse burst.
If the TPL Reverse Burst is programmed to None (disabled) via the
CPS, then the TPL reverse burst will not be transmitted at the end,
upon the PTT button release. If the TPL shut-off code is not
transmitted, then the receiving radio will not mute its speaker before
loss of a carrier is detected, unwanted noise (squelch tail) during loss
of carrier detection will be heard.
Table 2 shows the result of squelch tail elimination on the receiving
radio based on the TPL reverse burst setting on transmit and receive
radio.
When Reverse Burst is enabled in the CPS, the TPL Reverse Burst
that is transmitted at the end of the transmission changes the phase
prior to the removal of the carrier to eliminate the squelch tail.
There are 2 formats in use:
- Advances the phase of the tone forward 240 degree
- Advances the phase of the tone forward 180 degree
This setting is programmable in the CPS.
Table 2: Squelch Tail Elimination Results
TPL Tx Reverse Burst Setting Squelch Tail
Elimination
TPL Tx Reverse Burst
on Transmitting Radio
TPL Tx Reverse Burst
on Receiving Radio
Standard Yes
Non-Standard Non-Standard° Yes
Standard No
PM1200.book Page 18 Thursday, June 21, 2007 3:58 PM