July 22, 1992

PRO-43 800 MHZ Modification   Pat Murphy  Norfolk, Va.

I did the mod on the PRO-43 this morning and was very, very
happy with the results.  Yes it restores all of the cellular
at the 30khz spacing and the reception on 800 MHZ is superior
to anything I've seen so far, including the ICOM R-1.

Let me caution anyone wanting to do the Modification to be
SUPER CAREFUL.  This is a small unit with little working
space and unless you have a steady hand, excellent light,
don't try it.

USE THIS PROCEDURE AT YOUR OWN RISK.  I can only tell you
that I did it this way and it worked very well.

INSTRUCTIONS FOR PRO-43 CELLULAR RESTORATION
1. Remove the battery pack and cover.

2. Remove the four screws on back and GENTLY pry apart.

3. Remove the 6 silver screws from the 1st PC Board.

4. Remove solder from the ground pad and center feed
   conductor of the antenna directly under the antenna on the
   PC Board heat solder on top PC Board and center feed will
   loosen, this is the only really tricky part to this.

5. Disconnect the 2 plugs/wiring harness, make note of the
   color scheme for re-installing.  Harness has 2-metal
   guides on the side....BE CAREFUL NOT TO PINCH WIRES.

6. Lift top board away from bottom, paying careful attention
   the black plug near the bottom of the assembly, gently pry
   this apart.  DO NOT FORCE IT!

7. Remove 2-silver screws from the 2nd PC Board. (remember to
   replace on re-assembly)

8. Remove solder from the four points on the large silver
   shield covering the microprocessor board.  Remove shield.
   Make sure to replace shield on re-assembly as this serves
   as protection from intermod and interference.

9. Near the bottom you will see a row of surface mount diodes
   (very small and square, approx 1/32" long, black with gray
   markings)  These will be in locations marked D1, D2, D3,
   D4, D5.   Some of the locations are blank.

10.Use a very low temp iron (15-watt) and the smallest solde
   wick available, remove the solder from both sides of D4.
   Use hemostats or needle nose (very small) to grip while de
   soldering.  Remove diode D4.  Another method, you could
   use would be to (use magnifying glass) crush and remove D4
   with the needle nose pliers.  Make sure all of the pieces
   are removed and nothing is touching or connecting.
11.Once D4 is removed you will have full 800 MHZ coverage and
   30 KHZ spacing on cellular.

12. Carefully re-assemble unit remembering to double check
    before going on to next step.

 AGAIN - - USE THIS PROCEDURE AT YOUR OWN RISK!!!!

The 800 Mhz reception on the PRO-43 is superb.

When you've re-assembled the unit.  Hit MANUAL, PROGRAM,
LIMIT, 870.00 ENTER, HIT LIMIT UNTIL "H" APPEARS AND THEN
890.00 ENTER.  PUSH THE  "UP" ARROW AND YOUR IN BUSINESS.

With this modification, this really is a great radio.  ENJOY!

Patrick Murphy
Norfolk, Va.


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