

Article 10444 of rec.ham-radio:
Path: philabs!prls!pyramid!amdahl!bnrmtv!brandt
>From: [email-masked] (Adrian Brandt)
Newsgroups: rec.ham-radio
Subject: Re: Another PRO-2004 mods request
Summary: Here are some Pro-2004 modifications
Message-ID: <[email-masked]>
Date: 16 Mar 89 18:45:27 GMT
References: <[email-masked]>
Organization: Bell Northern Research, Mtn. View, CA
Lines: 51

In article <[email-masked]>, [email-masked] (Jay M Novello) writes:
> Since Radio Shack is discontinuing the PRO-2004 and cutting the price back
> to $299.00, I'd like to make a request for somebody with the cellular 
> modification to this fine set in a text file to please post it.

1. Remove the 4 philips screws on the back of the unit that
   hold the case onto the chassis.

2. Slide the radio out of the case by pushing it out the front.
   Or, put another way, slide the case back, off the radio.

3. Once you've eased the radio out, turn it upside down with the
   front toward you.

4. Locate a board with "PC-3" stenciled on it in big white letters.
   It is roughly in the middle of the radio near the back.
   There is a rectangular, highly reflective (mirror-like) metal
   cover covering most of this board.

5. Gently remove this metal cover.  It is held on by being press-fit
   over little metal dimples.  A little careful prying will do the
   trick here.

6. Once the cover is off you should see the main CPU chip on the
   right, a resonator crystal (501-X I think?) in the rear right
   corner, and a vertical row of diodes to the left of the CPU chip.
   Some of diode positions will be lableled like this  D-509, D-510,
   D-511, D-512, *D-513*, etc.  I don't remember exactly which ones
   are labled or not, but that's not so important right now, you
   should get the idea.

7. The diode D-513 is labled (I know) and this is the beastie that
   disables the cellular phone frequencies and their 30KHz search
   step size.  Snip this diode with diagonal cutters (or whatever).
   Make sure the snipped wire ends are not touching, and viola!
   You've got full 800MHz coverage on your Pro-2004.

8. You may want to test it at this point.  (Try entering 880 MHz or
   some other previously disabled 800MHz frequency, and verify that
   you don't get an ERROR.)  Re-assemble.

PS: There is a TURBO-Scan mod where you can up the scan speed to
around 30ch/s by replacing the resonator crystal in step 6 with a
10MHz version.  Also, by soldering in a diode in what would be diode
position D-510 (if it were labled) you can add 10 channels to each
bank for a total of 400 ch.  The problem with this is that then the
keypad's labelling for channel banks becomes incorrect.  You should
get and verify the complete details on the mods in this "PS" because
I can't supply you with complete instructions that I am 100% sure
about on these.  I'm just letting you know they're possible...