UBC60XLT-2. UBC68XLT, AE67H
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The Uniden Bearcat 60XLT-2, its UK version, the 68XLT, and its German version, the Albrecht AE67H look the same as the UBC60XLT-1. On the
inside however, things are completely different. In the 60XLT-1, the
discriminator IC can be reached by removing the scanner's back. In the
60XLT-2 / 68XLT, this IC is mounted on the bottom of the main PCB.
This scanner uses an SMD MC3361 receiver IC, and pin 9 contains the
baseband audio.
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UBC60XLT-2 / UBC68XLT
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Location of the MC3361
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The connection to pin 9
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A limiting resistor is connected to the MC3361's pin
9. The PCB has a rather large solder pad at pin 9, which makes
soldering easier. The resistor is fixed to the IC by a drop of
glue.
A piece of insulated wire is connected to the other lead of the
resistor. When the PCB is put back into the scanner, this wire can pass
between the PCB and the scanner's case to the other side of the
PCB. |
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Capacitor connected to the coil's
shield
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Twisted wire from the capacitor to the
3.5 mm terminal
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The discriminator output contains a rather strong 455
kHz component. By connecting the 10 k resistor to a grounded capacor, a
simple lowpass filter is created. I used a capacitor of 2.2 nF,
resulting in a cutoff frequency of about 7 kHz. The IF component is
surpressed effectively this way. The capacitor is connected to the
metal shield of the IF coil, which is grounded.
A 3.5 mm chassis terminal is mounted in the left bottom part of the
back panel. This terminal is connected to the capacitor and
ground. |
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