Check and adjust TX
•
Connect power meter/dummy load.
•
Select frequency (70.450.000).
• Press PTT
Check output power - set to 25W max using preset pot on RF board near 25D
connector.
•
Check frequency - adjust TCXO in centre screened compartment.
•
Check/adjust peak deviation using the preset pot to the front/left side of the screened
area.
Set to 2.5-3.0 KHz peak.
Check and adjust RX
•
Connect signal generator set to:
Frequency 70.450MHz,
Modulation FM 3KHz deviation,
Level 10uV.
•
Open squelch.
•
Adjust RX PLL preset tuning pot, rear of TCXO compartment on RX side, peak for
best signal - often approx 1/4 turn clockwise so that wiper is at 3 O’clock (towards
RX side of set).
N.B. There is a proper test point to measure the voltage, but this approach normally
works well.
•
Peak RX tuned circuits (the two section and three section filters) for best sensitivity,
reduce signal generator level as necessary.
•
Adjust gain reduction preset between the two filters, for best sensitivity.
Turn clockwise until you each the end of the track, and the signal drops significantly,
then turn clockwise for best signal.
• Close squelch and adjust Squelch preset (in front of front left corner of screened
compartment) for best operation.
Typically better than120dBm for 12db SINAD.
Reassemble the set
• Before reassembling the set it is worth checking the lithium battery to ensure that
settings are remembered by the set while it is disconnected from power.
o The battery should have a voltage of approx 3.6 Volts
N.B. The official replacement battery is quite expensive, a watch or computer
battery can be used – instead of mounting the battery inside the set, insulate it
and, mount it behind the front panel on fling leads.
o The chevron jumper pad adjacent to the battery should be jumpered with a blob
of solder
• As all good instructions say, reassembly is the reverse of disassembly!
Enjoy!
N.B. at frequencies of 70.000MHz and below you will get the error led on and the diagnosis
of RX VCO limit.
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General