know that his transmission is now terminated, and the radio returns to scan the channels for
receiving.
Caution:
If the Tx status keeps on engaging for more than 30 seconds*, the transmission is
automatically shut off and the radio returns to scan the channels for receiving. (*programmable
factor)
7. On the radios that have been receiving the message, the channel scanning is restarted when they
receive the End-of-Transmit signal. If the radio(s) can not, or failed to, receive the End-of-Transmit
signal, the channel scanning starts after 2.5 seconds* from the end of carrier wave being tuned in.
(*programmable factor)
8. When the Group #16 is selected by Group Selector Switch, the radio can be used as conventional
simplex two-way transceiver by simple PTT or VOX operation on this channel. This function can be
used for All Call of all radios in a Group.
9. To inactive particular Group(s) for Tx/Rx can be programmed though the frequencies are
programmed on all Groups’ channels. When the Group Selector Switch selects the inactive Group #,
the operator hears alerting signal as “Poop, Poop” for letting him know that the Group selected is
out of order.
10. When the battery runs low (voltage detection), the operator can hear short alerting tone such as
“Pu!, Pu!” for letting him know that the battery replacement is on order. When this tone is heard,
replace the battery
immediately.
Remarks:
This Low Battery alerting tone can be heard only in the Transmit status and may be
resumed in the Receive/Stand-by status. This is due to high current consumption required for
transmission. In any status when the Low Battery alerting tone is heard, it is requested to replace the
battery.
SET-UP
1. Hands tighten the Antenna by turning it clockwise on to the Antenna Connector on the top panel of
radio.
Caution:
There are 2 types of Antenna depending on the frequency bandwidth programmed on the SR21
radio.
#1:AT390 for 380-446MHz
#2:AT450 for 446-512MHz
Be sure to use the right Antenna for optimizing the performance. Use of wrong Antenna will make
insufficient coverage of communication area, and may cause malfunction of radio due to excessive load
put on the transmitter.
2. Mate the key guide of audio connector of Headgear or Ear Mic with the AF Connector (6 pin) on the
top panel of radio and press in. Turn the Lock Screw clockwise until it is firmly tightened.
3. If required, unscrew (turn counterclockwise) and take off the water-sealed cap on the Program
Connector (7 pin) on the top panel of radio, and mate the key guide of the audio connector of Remote
PTT Switch and press in. Turn the Lock Screw clockwise until it is firmly tightened.
Caution: Be sure to securely tighten the Antenna and all other audio connectors on right
position. Insufficient tightening of Antenna and connectors may cause improper
performance of waterproof.
