BC200/205XLT CELLULAR RESTORATION

Note: It is unlawful to monitor cellular telephone conversations. It is possible to monitor signals from the deleted

ranges even without conversion.

Simply add 21.7 MHz to the deleted frequency and enter the higher (image) frequency. Reception is virtually identical

in strength to that which would be heard on the deleted frequency. The frequencies deleted at the factory may be

restored, but the procedure must not be attempted by anyone unfamiliar with electronic circuitry. Grove Enterprises

assumes no liability for damage caused by this procedure. The modification will void your warranty.

TOOLS REQUIRED: Small Phillips screwdriver, small wire cutters.

1. Slide off the battery pack and remove the antenna from the scanner.

2. Using a small Phillips screwdriver, remove the two screws from the back of the scanner, the two screws which hold the

battery retaining spring at the base and the spring itself.

3. Carefully pry the bottom of the rear cover from the radio and remove the cover.

4. Locate the two small screws at the base of the circuit board and remove them. Gently pull the front panel

from the mainframe at the base and separate them.

5. Locate the (64 pin quad flatpack) microprocessor IC labelled "UNIDEN UC-1147" and the 10k ohm

(brown-black-orange) leadless resistor positioned above the letters "DEN" on the IC.

6. Using miniature wire cutters, cut the resistor body in two without disturbing anything else near it.

If the left solder pad comes loose, it may be peeled from the board. Brush or blow away any residue.

This completes the restoration.

REASSEMBLY

7. Insert the top of the front panel into the slot under the volume/squelch control panel and, noting carefully the

alignment of the dual inline 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 with the holes in the plastic standoffs

below them. Insert the two screws and gently tighten them.

8. Replace the back cover by inserting the top of the cover into the slot under the volume/squelch control panel;

press the cover into place, insert and tighten the screws.

9. Reposition the battery retaining spring (slotted side toward notched hole), insert the two remaining screws

and gently but securely tighten them.

10. Slide the battery pack into place; switch the scanner on to make sure the display comes on. If not, the battery is

discharged or the dual-inline connector was misaligned during assembly (see step 7).

Assuming the display comes on, press: MANUAL, 845.0, E; within two seconds, the frequency 845.000 should

appear on the display. Cut the resistor located just above the UC1147 chip rated at 10k.

............................................< 10k >

...........................___________________

...........................I........UC 1147..............I

...........................____________________

Modification for Putting BC-220XLT In AM Reception Mode

I have come up with a crude mod for the BC200xlt scanner to allow AM reception in the 136 to 174 range.

Why would I want AM in this range you ask? well I attend several Air shows during the year and the

Thunderbirds use 140 mhz area fregs. As we all know the Uniden switches to FM in this range, causeing very

distorted reception (slope detection). Somebody else may have already thought of this idea (you?) but here goes.

Break the AIR Trace between dual diode D31 and IC1 pin 8. Connect the center of a single pole - double throw

mini switch to the trace leading back to IC1 pin 8. Connect one of the other poles to the trace leading back to D31.

This is the "Normal" mode(This just restores what you have cut). Now connect the other pole to the VHI (VHF HI)

line at a easy to locate point. This is the "AM" mode. What will happen now is when AM is selected the VHF and

VHF air band will all be in the AM mode. UHF and others are not affected. When in the normal mode everything is

just like it always was. I have done this mode over a year ago so it's still a cloudy in my memory. But it works like this:

The microprocessor sends a high to Q7 to select the AIR mode, by routing the VHI signal around D31 by means of the

switch the AM detector is reselected. Normaly D31 blocks out the VHI signal allowing FM in the VHF HI range.

I hope my explaination of this mod is clear. It does take some delicate surgery to do. I also hope I haven't duplicated

anyone elses idea.