User's Manual

MaxonSM5102Radio
2.2 Alignment
WARNINGS
Any repairs or adjustments should only be
made by, or under the supervision of, a
qualified radio-telephone service technician.
CAUTION
This radio contains static sensitive devices.
Static safe precautions should be observed,
in particular we would recommend the use of
a suitable floor mat, table mat, bonding cords
and a wrist strap. The soldering iron should
have an earthed tip.
Care should be exercised in the handling of
static sensitive components and they should
always be transported in the correct
containers.
Never remove, or insert, static sensitive
devices with the power applied.
2.2.1 Disassembly and Re-assembly of
the Radio
In order to carry out the following Test and
Alignment procedures it will be necessary to
gain access to the inside of the radio.
Care should be exercised when opening up
the radio for maintenance or repair.
Removing and replacing the main cover
Turn the radio over, so that the radio is
upside down.
Remove the four chrome screws.
Lift the cover off.
Replace the main cover by reversing the
above procedure.
Removing and replacing the front panel
Firstly, remove the main cover, as described
above.
With the radio upside down, remove the two
black screws which hold the front panel to
the base of the radio.
Turn the radio the normal way up. Remove
the three screws which secure the front panel
to the radio. It is important that you note that
one of the screws is different as it secures
metal and not plastic.
Remove the front panel.
Replace the front panel by reversing the
procedure.
Rx VCO
a. Select Channel 1.
b. Check that the VCO tuning voltage at
TP1 is >1.8V
c. Select Channel 3
d. Check that the voltage at TP1 is <10V
e. If the voltage is >10V it will
be necessary to repeat paras a to d,
reducing the voltage set in para b nearer
to 1.8V.
Tx VCO
For UHF only
a. Select Channel 1.
b. Set the PTT switch to on. Check that the
VCO tuning voltage at TP1 is >1.5V.
c. Set the PTT switch to off. Select
Channel 3.
d. Set the PTT switch to on and check that
the voltage at TP1 is <10V.
e. If the voltage is >10V it will be
necessary to repeat per as a to d,
reducing the voltage set in per a b nearer
to 1.5V.
f. Set the PTT switch to off.
TCXO
a. Select Channel 2.
b. Set the PTT switch to on.
c. Using the frequency counter, adjust the
TCXO control, so that the transmit
frequency is within +/- 100Hz of the
required frequency.
d. Set the PTT switch to off.
If no further alignment is to be carried out, it
may be necessary to reset the squelch.