Kirisun DM588, Service Manual

Page: 25 / 151

DM588 Service Manual
Item Environment
Measurement Tool and Method
Index Requirement
Test Device Test Point Tool Method
7. 4FSK
error
Digital
MOD1
Set
general-purpose
tester to TX
state.
(After resetting
the tester, TX
TEST is set by
default.)
General-purpose
tester
Connect
antenna
interface of the
radio to RF
IN/OUT interface
of the tester
PC
1) Run the debugging software on the
PC, and set the tester to adjustment
mode.
2) Go to the DMR test interface. Set
the RECEIVER frequency of the
tester to a low transmitting frequency
of the radio.
3) Decrease the Digital MOD2 to 0,
adjust the Digital MOD1 so that the
Symbol Deviation reaches about
1944±100Hz, adjust Digital MOD2,
and observe whether 4FSK Error
decreases. Repeat adjusting finely
Digital MOD1 and Digital MOD2 to
get an ideal 4FSK Error.
3) Test high-frequency and
medium-frequency channels using
the same method.
4FSK ERROR<5%
1944±100Hz
Digital
MOD2
22