Application Notes A. Receiver Audio Level Testing; Transmitter Deviation; Receiver Sensitivity - Motorola R2010D Operator's Manual

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 1 KHz modulation level to 2.9 KHz devia-
tion.
7) With junction box compandor switch in NOR-
MAL mode, adjust radio for 100 m V RX audio
while in DVM/D1ST display on R2008D. Refer
to radio maintenance manual.
8) increase 1 KHz deviation to 8 KHz, read distor-
tion in either DVM/DIST or GEN/MON
display.
9) Data distortion: Using DVM/D1ST display, and
with modulation still 1 KHz at 8 KHz deviation,
measure level at discriminator test point Uunc-
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 1 KHz modulation off. Adjust
code synth output for 8KHz deviation using tone
A and note level at radio discriminator. Dif-
ference in level from that noted with 1 KHz mod-
ulation should be less than 3 dB.
10) Audio frequency response: Bypass the trans-
ceiver com pandor. .. use the Signaling Sequence
display to set tone A to 300 Hz, and tone B to
3000 Hz. 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
15
B. TRANSMITTER DEVIATION
1) Connect R2008D to transceiver unit via the junc-
tion box, as in manual test mode connection.
(Refer to Fig. 13.)
2) Select power monitor mode and execute the fol-
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 TX
audio connector on junction box. Set either 1
KHz level or code synth level using modulation
display and observe deviation on GEN/MOD
display. Use Signaling Sequence display to vary
frequency of tone A or tone B to check deviation
on frequencies other than
I KHz.
Send manual
mode command 13 TX mute to mute transmitter
audio for further tests.
4) Signaling tone deviation can be set by sending the
manual mode command 16, Signaling Tone On,
to the transceiver unit. Set deviation to 8 KHz
measured on GEN/MON display. Manual mode
command 17, Signaling Tone Off, will deactivate
the transceiver signaling tone generator.
5) DTMF deviation can be set by executing manual
mode command 42, DTMF On, and inputting
desired digit such as 06. Adjust the transceiver
for approximately 8.5-9 KHz deviation (roughly
equal to 9 radians peak phase deviation).
6) SAT deviation can be set by executing manual
mode command 32, SA TON, and entering 01.
Set SAT deviation to 2 KHz.
C. RECEIVER SENSITIVITY
1) Connect R2008D to transceiver unit via the junc-
tion box. (Refer to Fig. 13.)
2) Execute the following manual commands:
01 Suspend
09 Load synthesizer (to desired channel)
12 Receiver unmute
3) Connect RX audio (on junction box) to R2008D
sinad input.
4) Set R2008D to generate on desired frequency
(870
+
channel # X 0.03 MHz), with 1 KHz
modulation at 8 KHz deviation.
5) Bypass the compandor on the transceiver unit.
6) Adjust the RF output level on the R2008D for a
12 dB sinad reading in GEN/MON display.
.NOTE: One can expect to see a difference of about 1
dB of RF level between a C-message
weighted sinad measurement and a flat
weighted sinad measurement on the
R2008D, i.e. -115dBm on the R2008D cor-
responds approximately with -116dBm
C-message weighted.