Speeding up the scan/search rates for the Uniden BC-200/205
XLT
You will need a small crystal or ceramic resonator in the
600-800
kHz range.
1. Disassemble the unit to access the microprocessor area.
a. Slide off the battery pack.
b. Remove the two screws from the rear of the scanner and the
two screws that hold the battery retaining spring at the
base. Then remove the spring.
c. Carefuly pry the bottom of the rear cover from the scanner
and remove the cover.
d. Locate the two small screws at the base of the circuit board
and remove them. Gently pull the front panel from the main
frame at the base and separate them. If you separate them
between the two layers. Remember that for later reassembly;
the pins will have to be lined up perfectly before you slip
the sections back together.
2. Search around the logic/CPU board (Uniden calls it the
"MICOM
PCB Assembly"), and locate Y-201, which is a little rectangular
component. This is the stock 400 kHz resonator. Your
replacement can be a bit larger if necessary, but not grossly
so.
3. Carefully desolder and remove Y-201. Put it in safekeeping
because you may want it for something else someday.
4. Install (solder) your newly procured replacement clock
resonator, be it a crystal or another ceramic resonator, where
Y-201 came out.
5. Reassemble: Insert top of the front panel into the slot
under
the volume/squelch control panel. Carefully noting the alignment
of the dual in-line connector at the bottom of the board with
the mating socket, press the front panel firmly into place. Be
sure that the holes at the bottom of the circuit board line up
two screws and tighten them
6. Replace the rear cover by inserting the top of the cover
into
the slot under the VOLUME/SQUELCH control panel. Press cover
into place. Insert and tighten the screws.
7. Reposition the battery retaining spring (slotted side toward
notched hole). Insert the two remaining screws and gently
tighten them.
8. Slide the battery pack into place. Switch scanner on to
ensure that the display comes on. If not, the battery may be
discharged or the dual in-line connector may have been
misaligned during reassembly (step 5). Another possibility
would be that the new resonator either doesn't work, is
unsuitable, or may have been incorrectly installed. Another
possibility (if you installed something greater than 800 kHz
is that it's just too fast.
Assuming that the display comes on, leave the antenna
disconnected,
and run a speed test. Speed in channels-per-second equals the number of
channels divided by the time in seconds. Using a Murata-Erie 800 kHz
Note that the channels must have frequencies programmed into
them.
"Empty" or 0000.000 MHz channels run faster and throw off the
calculation.