Motorola M110 User manual

Motorola M110/MC micro aligment (VHF)
1. ALIGMENT
Note: Key the radio while making adj stments or meas rments.
1.1 GENERAL
Perform all adj stments at a s pply voltage 13.2 ~0.1 volts dc, nless the instr ction call for a
different voltage.
Interpret instr ction to t rn controls clockwise (CW) or co nterclockwise (CCW) to mean »as viewed
from the component side of the circ it board«.
Pict re A and B show the locations of the components.
When yo perform any of the t ne- p proced res given in sections 1.2, 1.3, 1.4 and 1.5, the radio
m st be completly assembled except for the chassis cover, top cover of the synthesizer compartment,
and the radio sleeve. When yo have completed the t ne- p, install the synthesizer cover, chassis
cover and sleeve before testing the radio against specifications following the proced res given in
sections 1.4, 1.5, 1.6 and 1.8 .
The following test eq ipement is recommended for aligning and servicing the MC micro radio:
R2001D Comm nication System Analyzer
or
R2200B Service Monitor
GTF180A Mobile test set with
GTF244A Adapter cable for MC micro
PFT4053A Psophometric filter
FTP3005B Select 5 test nit (not rq ired with R2001D)
R1001B Power s pply
or
S1347D Power s pply (for radios with 10 watts or less power)
R1037 Digital m ltimeter
or
R1024B Digital m ltimeter
1.2 TO ADJUST THE TRANSMITER
(1) Preset the following pots:
* HI PWR R453 F lly CCW
* LO PWR R455 F lly CCW
* VOLT LIMIT R463 F lly CW
(2) Adj st the radios dc s pply voltage to 13.2 ~0.1 VDC (12.6 VDC for MAU1, six-watt model).
(3) Select the channel with highest transmit freq ency.

(4) Connect the radio anrenna o tp t to an acc rate RF power meter that provides a 50-ohm load.
(5) Connect a dc voltmeter from the steering line test point (SL) to gro nd. Meter impedance sho ld
be 11 megaohms or more.
(6) Key the radio and adj st coil L210 ntil the voltage reads 7.0 VDC
(7) Select the channel with the lowest transmit freq ency. Key the radio and verify that dc voltage is
at least 2.5 VDC
(8) Select any transmit channel. (If radio has the MAB889 slaved RF power option, select any high
power transmit channel).
(9) Key the radio and adj st R453 (HI PWR) for:
Model number Power se ing
MAU0 1.0 W
MAU1 6.0 W
MAU2 10.0 W
MAU3 25.0 W
(10) Switch thro gh all channels (all high power channels for MAB889). On each channel key the
radio and note the power o tp t.
For MAU0, MAU2 and MAU3 models note tha channel that gives tha minim m power o tp t;
for MAU1 models note the channels that gives
The maxim m power o tp t. If more than one channels gives tha same maxim m or minim m
power, chose any one of those channels.
(11) Switch thro gh all transmiot channels (all high power channels for MAB889). On each channel,
key tha radio while watching tha dc voltage at Pin 4 of connector P6, or at test point CV on the
command board. Record the n mber of the channel that gives the greatest voltage and what voltage
is. (If more than one channel gives the same maxim m voltage, chose any of those channels). If it
is greater than 10.0 VDC, go to step 14 if not go to step 12.
(12) On the channel that step 11 shoved to have the highest dc voltage, t rn R463 f lly CCW. T rn
R453 f lly CW.
(13) Key the radio. Adj st the voltage limit pot R463 for a dc voltage 2.0 higher than voltage level
recorded in step 11, as meas red at Pin 4 of P6 or at test point CV
(14) Set the channel selector to the chennel that was noted in step 10. Key the radio and adj st R453
for:
Model number Power se ing
MAU0 1.1 W
MAU1 5.6 W
MAU2 10.7 W
MAU3 26.8 W

(15) Verify that all channels (all high power channels in MAB889) prod ce at least 1.0, 10.0 or 25.0
watts as appropriate for MAU0, MAU2 and MAU3
models. Verify that no channels prod ces more than 6.0 watts for MAU1 models.
(16) If the radio has option MAB889 (slaved RF power level) select any low power channel. Key the
radio and adj st R455 for an o tp t power of 1.0 watt
(or other specified power setting) for MAU1 and MAU2 models. Verify that the RF power o tp t
on all low power channels is between 0.7 and 1.4 watts.
Readj st R455 slightly if necessary. For MAU0 models, adj st R455 for an o tp t power of 0.1
watt or some other specified power level. Verify that
RF power o tp t on all low power channels is between 70 and 140 mW.
1.3 TO ADJUST THE REFERENCE OSCILLATOR
(1) Connect the radio antenna o tp t to an acc rate freq ency co nter thro gh a s itable atten ator.
(2) Select any trasmit channel.
(3) Key the radio and adj st L151 (all models except those with 2 ppm stability) or R163 (models
with 2 ppm stability) ntil the exact transmit freq ency (~100 Hz) apears on the co nter.
(4) Check all transmit channels to verify that the correct transmit freg encies have been programed.
1.4 TO ADJUST THE DEVIATION
(1) Connect the radio antenna o tp t to a mod lation analyzer or test receiver thro gh a s itable
atten ator
(2) Connect an a dio oscilator to the mocrophone a dio inp t thro gh the circ it in fig re C. Set the
oscillator frq ency to one kHz and the o tp t level to
800 mV RMS.
(3) Preset pots R302 (VCO MOD) and R305 (REF MOD) f lly CCW.
(4) Select any transmit channel. For PL models select channel that transmit PL.
(5) Key the radio and adj st the VCO MOD pot R302 for appropriate deviation level:
Channel spacing Devia ion se ing
25 kHz ~ 4.6 kHz
20 kHz ~ 3.7 kHz
12.5 kHz ~ 2.3 kHz
No e
If + and – deviation readings differ, se only the higher reading.
(6) Change the a dio oscilatror freq ency to 200 Hz and maintain tha o tp t level at 800 mV RMS.

(7) Key the radio and observe tha waveform on an oscilloscope connected to demod lated o tp t of
a test receiver. Test receiver sho ld be non-deemphasized and there m st be dc co pling between
the test receiver and the scope. (AC co pling is s itable if the corner freq ency is 2 Hz or lower.)
Adj st R305 (REF MOD) for the flattest sg are-wave response with minim m tilt.
(8) Ret rn the a dio oscilator freq ency to one kHz, 800 mV and repeat step 5.
1.5. TO ALIGN THE RECEIVER
No e
Adj st the transmiter VCO and reference oscilator before aligning the receiver
1.5.1 Receiver VCO
(1) Connect a high impendance (11 megaohms or greater) dc voltmeter from steering line test point
(SL) to gro nd.
(2) (Radios withmore then one receive freq ency) Select the channel with highest receive freg ency.
(3) Adj st the receiver VCO coil (L201) ntil the voltage meters reads 7.0 VDC.
(4) Select the channel with the lowest receive freq ency and verify that test freq ency is at least 2.5
VDC.
1.5.2. Receiver
(1) Find the t ne- p freq ency , ft ne as follows:
(a) On single channel radios and m lti chanel radios with a single receive freq ency: ft ne = freceive
(b) On m lti chanel radios that have a receive bandwidth of two MHz or less: ft ne = freq ency of
highest freq ency channel
© On m lti channel radios that have a receive bandwidth greater than two MHz b t less than or
eq al to fo r MHz find fmid where:
fmid = (fhighest + flowest) : 2
If one of the radio channels has a freq ency within 500 kHz of fmid perform the t ne- p on that
channel. If not yo m st either get a t ne- p PROM
programed to fmid or program the t ne- p freq ency fmid into the radio (EZ models only). EV
models contain a preprogramed t ne- p channel, accessed by
temporarily sho rting the TEST pins on the command board.
(2) Set the channel selector switch to the channel of the t ne- p freq ency as determined in step 1
above
(3) Connect a two ohm resistive load acros Pin 4 of J5 (hot lead) and Pin 5 of J5 (gro nd lead).
Monitor the a dio o tp t across this load resistor.

(4) Preset the sl gs of L1 thr L7 for ft ne fl sh with the circ it board.
(5) Connect a dc voltmeter from the local oscilator test point (LO) to gro nd.
(6) Peak the injection filter coils L6, L5 and L7 in that order, for maxim m dc voltage typiclly
between 2.1 and 3.5 VDC. Repeat ntil yo cannot make the dc voltage increase any farther.
(7) Connect an RF signal generator to the anrenna connector and adj st it to generate an nmod lated
on channel signal strong eno gh to q iet receiver.
(8) Connect an ac voltmeter with bandwidth of at least 500 Hz (an HP331A distortion analyzer) from
the IF test point to gro nd. Increase the RF generator o tp t ntil the ac voltmeter idicates
approximately 30 mV. Adj st the RF filter colils L1, L3, L4 and L5 ntil the voltmeter peaks.
Red ce the generator`s RF level as necessary to maintain approximately 30 mV RMS on the
meter d ring this process. Repeat the adj stmen ntil yo can get no f rther increase in voltage.
(9) Set the RF level of the generator 1 mV. Mod late it with 1 kHz at 60% of f ll system deviation.
F ll system deviation for channel spacing of 25 kHz is
~ 5 kHz; for 20 kHz ~ 4 kHz; for 12.5 kHz ~ 2.5 kHz. Adj st the vol me control to get an a dio
level of abo t one volt RMS acros the 2 ohm load. Slowly peak the q ad coil, L54 for maxim m
a dio o tp t.
(10) Adj st the sq elch as follows:
(a) Preset the sq elch control R59 CCW.
(b) Apply an on-channel RF signal at a level of one mV. Mod late with a one kHz tone at 60% of
f ll system deviation.
© Adj st the vol me control for 1.7 volts RMS across the two ohm load.
(d) Red ce the RF level ntill the CCITT-weighted SINAD is 10 dB.
(e) Enable the carrier sq elch mode with the front panel switch.
(f) Slowly t rn the sq elch control CW ntil the a dio is sq elched (m ted) then very slowly t rn
CCW ntil the radio j st nsq elches ( nm tes)
(g) Red ce the generator RF level to zero slowly increase the level ntil the radio j st nsq elches and
verify that tha CCITT-weighted SINAD at this RF level
is between 8 and 12 dB SINAD. Readj st R59 slightly if necessary.

Pic ure »A«
Aligmen poin s on RF board

Pic ure »B«
Aligmen poin s on command board

Pic ure »C«
Connec ing Audio Oscilla or o microphone
This is a transcript from service manual, there might be some tipo errors in the text, so I
can not overtake any responsibility of any sort of the possible damages to your radio.
Beno, s56kzn
AUDIO
OSC.
47 F
16 V
560 ohm
5 %
¼ watt
TO J5 PIN 6
(OR TO J1001 PIN 4)
TO J5 PIN 2
(OR TO J1001 PIN 5)
HI
GND
+