Uniden UH810S Owner's Manual page 18

Operation
channel by channel, if desired, but for Master Scan to work effectively
each radio in the group must have the same channels in its GS memory.
To add/remove channels from GS SCAN Memory, refer the section
above.
RX only Channels (CH22, CH23, CH61, CH62 and CH63)
will not be included in MASTER SCAN Mode even though
stored into GS Memory. Also channels for which Duplex
NOTE
Setting are On will be skipped in MASTER SCAN Mode.
To operate in MASTER SCAN mode,
1. Press [MENU/MEM] 7 times.
2. Press ▲ or ▼ to change the setting to M.SCAN (Master Scan),
SCAN (Open Scan) or GS SCAN (Group Scan)
3. Press & hold [MENU/MEM] to save and exit.
To change MASTER SCAN settings,
1. Press [MENU/MEM] key 8 times. The M.SCAN setting ashes.
2. Change to the following setting by pressing
P-: Master Scan uses current CH in GS memory
P1: Master Scan uses CH09-20 in GS.
P2: Master Scan uses CH21-30, 39, 40 in GS.
P3: Master Scan uses CH49-60 in GS.
P4: Master Scan uses CH61-70, 79, 80 in GS.
UNIDEN UH810S/UH820S
▼ or
18
Handheld UHF-CB Transceiver
▲ .