5.0 Application Notes; Receiver Audio Level Testing; Transmitter Deviation; Receiver Sensitivity - Motorola R-2002A Manual

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5.0 APPLICATION NOTES
A. RECEIVER AUDIO LEVEL TESTING
1) Connect R2008D to transceiver unit via junction
box. (Refer to Fig. 13)
2) Disconnect duplex generator output if con-
nected. -
3) Select generator function and execute the follow-
ing manual mode commands:
01 Suspend
09 Load synthesizer (enter desired channel)
12 RX unmute
4) Set R2008D to desired channel (870 MHz plus
.03 X channel
#)
ex. 879.99 MHz equals channel
333.
5) Connect RX audio BNC connector on junction
box to Vert/Sinad input on R2008D.
6) Select GEN function on R2010D. Adjust the out-
put level to -50 dBm
to
simulate a strong signal.
Adjust I KHz modulation level to 2.9 KHz devia-
tion.
7) With junction box compandor switch in NOR-
MAL mode, adjust radio for 100 mV RX audio
while in DVM/DIST display on R2008D. Refer
to radio maintenance manual.
8) Increase 1 KHz deviation to 8 KHz, read distor-
tion in either DVM/OIST or GEN/MON
display.
9) Data distortion: Using DVM/DIST display, and
with modulation still I KHz at 8 KHz deviation,
measure level at discriminator test point (junc-
tion box test point for AMPS bus compliant
radios, internal radio test point for others). Us-
ing Signaling Sequence display, input 9999.9 Hz
for tone A. Turn I KHz modulation off. Adjust
code synth output for 8 KHz deviation using tone
A and note level at radio discriminator. Dif-
ference in level from that noted with I KHz mod-
ulation should be less than 3 dB.
10) Audio frequency response: Bypass the trans-
ceiver compand or. Use the Signaling Sequence
display to set tone A to 300 Hz, and tone B to
3000Hz. Using a constant deviation level of 2.9
KHz check the level at the RX audio jack.
Typical output levels are:
300Hz 331 mV
1000Hz 110 mV (REF)
3000Hz 33 mV
AUDIO RESPONSE IS -6 dB/OCTAVE
DEEMPHASIS
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B. TRANSMITTER DEVIATION
l) Connect R2008D to transceiver unit via the jUJ
tion box, as in manual test mode connectic
(Refer to Fig. 13.)
2) Select power monitor mode and execute the f,
lowing manual mode commands:
01 Suspend
09 Load synthesizer, enter desired channel
07 Carrier on ·
14 TX unmute
3) To check deviation, connect mod out jack to l
audio connector on junction box. Set eithet
KHz level or code synth level using modulati
display and observe deviation on GEN/M(
display. Use Signaling Sequence display to v;
frequency of tone A or tone B to check deviati
on frequencies other than 1 KHz. Send man·
mode command 13 TX mute to mute transmit
audio for further tests.
4) Signaling tone deviation can be set by sending
manual mode command 16, Signaling Tone (
to the transceiver unit. Set deviation to 8 K
measured on GEN/MON display. Manual me
command 17, Signaling Tone Off, will deactiv
the transceiver signaling tone generator.
5) DTMF deviation can be set by executing man
mode command 42, DTMF On, and inputt
desired digit such as 06. Adjust the transcei
for approximately 8.5-9 KHz deviation (roug
equal to 9 radians peak phase deviation).
6) SAT deviation can be set by executing ma11
mode command 32, SATON, and entering
Set SAT deviation to 2 KHz.
C. RECEIVER SENSITIVITY
I) Connect R2008D to transceiver unit via the jl
tion box. (Refer to Fig. 13.)
2) Execute the following manual commands:
01 Suspend
09 Load synthesizer (to desired chan
12 Receiver unmute
3) Connect RX audio (on junction box) to
R2~
sinad input.
4) Set R2008D to generate on desired frequ€
(870
+
channel # X 0.03 MHz), with I I
modulation at 8 KHz deviation.
5) Bypass the compandor on the transceiver ur
6) Adjust the RF output level on the R2008D f
12 dB sinad reading in GEN/MON display.
NOTE: One can expect to see a difference of abc
dB of RF level between a C-mes
weighted sinad measurement and a
weighted sinad measurement on
R2008D, i.e. -115dBm on the R2008D
responds approximately with -116c
C-message weighted.