PRO2006.1

Radio Shack PRO-2006 Scanner Mods
by Mark A. Day  N4OQK @ CHO

Introduction

The PRO-2006 is probably the worlds most versatile scanner to date.
Modifications are easily implemented, and upgrade performance over stock
units tremendously. Enjoy, and keep scanning!


Mod#1 : Cellular restoration
Parts : NONE

        To restore the missing CMT frequencies, merely clip diode D502.
        It is located in the upper left corner of the CPU/display board.


Mod#2 : Scan rate increase
Parts : 16Mhz. Quartz Crystal - fundamental cut

        Replace CX503 (12Mhz) with a 16Mhz crystal, clip diode D503 (near D502)
        The unit now scans at around 40 channels per second.


Mod#3 : Squelch hysteresis suppression
Parts : 100-200K ohm 1/8w resistor

        Locate R152 (33K) on the linear PCB (main board). This is a tricky
        resistor to get to, since it is on the bottom side of the board.
        Remove this resistor, and replace it with a 100-200K resistor. The
        higher the resistance, the less hysteresis will be present. I found
        100K gave me all the razor-sharpness I was looking for, without
        sacrificing performance.


Mod#4 : "S" meter output
Parts : 10Kohm 1/8w resistor, 0.1 uf capacitor

        Locate D33 on the linear PCB. Solder in the 10K resistor to the ANODE
        of this diode. Note this is not the same as TP2. Connect a wire from
        the free end of this resistor to a rear panel jack (RCA). Solder the
        0.1uf capacitor from the jack's center terminal to ground. Output on
        this jack follows the AGC voltage. Negative for no signal, goes
        positive when a signal is present, increasing with signal strength.
        A 1Volt full scale panel meter makes a good "S" meter


Mod#5 : Increased headphone audio
Parts : NONE

        Locate resistor R228 (27 ohm) on linear board (near IC7).
        Remove this resistor and replace it with a jumper wire.