From: [email protected]
Newsgroups: rec.radio.shortwave
Subject: Realistic PRO-2022 Cellular Restoration
Message-ID: <[email protected]>
Date: 30 Sep 91 13:50:04 GMT
Sender: [email protected]
Lines: 49


       Cellular Restoration on the Realistic PRO-2022

The Realistic PRO-2022 certainly is a look-alike for the all-time
popular, but now-discontinued, PRO-2005. But is the similarity only
cosmetic? What tricks can be done to increase the utility of the
lower-cost 2022, now availible from Radio Shack and Grove Enterprises?
Of the greatest interest, can cellular phone coverage, censored at the
factory, be restored? Yes.

After removing the two upper back screws and the top lid, locate the
black cable just behind the front panel. Adjacent to the cable are
four diodes locations: D42, D43, D44 and D45.

       D42     is not present; installed, it adds the 68-88 MHz
               European mid band (which includes the US 76-82 MHz
               mid band), removing the US 30-54 MHz low band. Even
               if a switch were installed to allow the diode to be
               selected, additional components and realignment are
               necessary for that higher frequency coverage. Don't
               do it!

       D43     is present, allowing the 800 MHz band to be received;
               the diode may be deleted so that the same microprocessor
               may be used in scanner modles which don't have that
               800 MHz capability. Don't touch it!

       D44     is present, deleting the cellular mobile and base
               frequencies. If one lead is cut, total 806-960 frequency
               is restored, including 30 kHz steps in the cellular
               band. Keep in mind, however, that mobile telephone
               eavesdropping is prohibited by the Electronic
               Communications Privacy Act!

This modification may void your warrenty; it is best to cut the lead
carefully, gently separating the gap slightly so that it may be resoldered
in case the radio needs warrenty repair later.

       D45     is not present; installed, it makes the cellular 30 kHz
               increments change to 12.5 kHz. A small SPST switch
               connected in series with one lead of a 1N914 or 1N4148
               could allow selection of the 25 kHz step interval in
               those areas which utilize that channel spacing.

To do this, it is necessary to unsolder a shield under the circuit
board which covers the solder pads for the diodes. Such a modification
should only be attempted by someone familiar with electronic circuitry.

[Excerpted from Monitoring Times, June 1990, page 89.]