

Article 14531 of rec.ham-radio:
Path: philabs!prls!pyramid!decwrl!ucbvax!pasteur!ames!mailrus!sharkey!indetech!mdc
>From: [email-masked] (Mark Copple )
Newsgroups: rec.ham-radio
Subject: PRO-34 Novice Notes (mods)
Message-ID: <[email-masked]>
Date: 28 Sep 89 18:57:22 GMT
Reply-To: [email-masked] (Mark Copple )
Distribution: usa
Organization: Independence Technologies, Inc. Fremont, CA
Lines: 255
Disclaimer: Author bears full responsibility for contents of this article

  Yesterday afternoon I received the mods instructions for the Pro-34 scanner
to add complete 800mhz and 66-88 mhz coverage. I was so excited that I 
started dissassembling the beast at my office with the tools at hand. One of the
tools NOT at hand was a soldering iron and for lack of a lighter and a sewing 
needle I postponed the completion of the mods until I got home. Once completed
I verified previous operation and then checked to see that the mods worked. Yup
I am much pleased with the results.  I would like to thank Sam Jones for his 
original Mods instructions.

  The Following instructions are a result of a request for the coverage mods for
the PRO-34 scanner. I made the assumption that the requester had never opened up
their scaner before. 
  The instructions below are for those that don't like to completely dissassemble
every new electronic toy they buy just to see how it works. Nor is it for the
guy that has been building their own equipment since the days of the first 
tube diode. This set of instructions assums a moderate level of skill with a 
soldering iron, and some simple hand tools. It is aimed at those who just want
the additional coverage from the mods but havn't been building kits for a decade.
 lets just call these ....

                 "NOVICE NOTES" FOR PRO-34 MODIFICATIONS

1.  Remove the 4 small phillips scres on the back of the unit

2.  Remove the batter cover and battery holder from the case.

3.  Remove the two knobs on the top of the case (Volume &  Squelch)

4.  The Case has some pressure fit points, These are at the bottom of
    the case and you need to be a bit careful in forcing the two halves
    of the case shell appart. Once you have the pressure fit points 
    at the bottom released, angle up the bottom of the case until
    the battery sepperation wall is clear of the internal metal frame, and 
    slide towards the top of the unit, place the back half of the shell aside.

5.  Now you will see the RF boad mounted to the metal support frame, The 
    BNC (antenna) conector leads and the volume control power switch leads
    are soldered directly to the board. Carefully desolder these 4 connections.

6.  At the bottom of the RF board there is a IF Can transformer that has a small
    wire as a groundign strap soldered directly to it. Desolder this as well.

7.  There will be some wires from the volume controle knob to the PC board that
    are socketed. Remove the plug from the RF board (needle nose pliers work)

8.  There will also be a similar wire (small sheilded ) from the squelch control
    to the RF board wich is also Socketed. Remove the plug from the RF board.
    (Again Needle Nose Pliers work good here)

9.  Remove the 4 thredded stand-offs from the RF Board (these Hold the RF board to
    the internal mettal frame and are where the screws that hold the back of the
    case on go.) Use a nut driver or Needle Nose Pliers.

10. Now there the RF board is mostly free. The only thing holding it in is the row
    of connector pins on its botom side that plug into the logic board. You will
    need to pry this board up gently. Be warned that the bottom side of the RF 
    board is just chock full of Very Small surface mounted components. So use 
    something non-metalic and smooth to do the prying with.

11. Now that you have removed the RF board, place it along with the case shell back

12. The Internal Metal support frame is now exposed. there are 3 small phillips
    screws holding the mettal frame to the bottom Logic board (actually, these
    screws go through the logic board and into the front half of the case.)
    2 of the screws are near the top, and 1 is at the bottom of the metal frame.
    remove these 3 screws.

13. There is a small socketed wire that leads from the small power pc board on the
    metal frame that goes under it and is pluged into the Logic board. Lift
    the metal frame up and remove the power plug from the PC board. Place the 
    metal frame with the rest of your parts pile.

14. You are have the component side of the  Logig board exposed now. There are
    2 small phillips screws at the bottom of the PC board (where the Battery 
    compartment WAS) Remove them.

15. Once you have the the last 2 screw removed the Logic board is free. The
    speaker wires lead from the speaker to the logic board on the bottom side.
    These are soldered in but there is enough play in them to allow you to
    make the mods.

16. NOTE: The keyboard lock switch is a funky little piece of plastic with
    a sliding stainless metal contactor that is just wedged inbetween the
    front case and the logic board. Remove both the switch contacts and the
    plastic switch. (best know it now or loose them in the carpet)

17. On the component side of the PC board you will see lots of nifty surface
    mounted components, a fat little barrel capacitor (used for maintaining the
    channel freqs while you change the batteries.. and make modifications :)
    near the edge of the PC board you will see a couple of small diodes moutned
    vertically. These will be labeled on the PC board as D10 and D11, you will
    also see a place for another diaode to be soldered in but was not 
    installed at the factory.. this is D9.

18. You must now move diode D11 to the place where D9 is labled. As you have
    probably noticed by now there is a tin cover over about 1/2rd of the
    PC boards solder side. The edge of the tin cover nearest the diodes has
    2 metal tabs soldered to the PC board. Desolder these 2 tabs and gently
    bend the metal cover way from the soder side of the PC board. This will
    expose the board enough to let you get your soldering iron in to where
    the diode leads are.

19. Desolder the D11 diode from the bottom while pulling it away from the board
    on the top  of the board using neadle nose pliers on the LEAD only.

20. Now heat up the D9 solder pads and insert the diode (the same way it was 
    oriented in the D11 location)

You Have Completed the Mods for complete 800mhz band coverage and 66-88mhz band
coverage.

Follow the same steps backwards (20->1)and replace "remove" with "replace"
and "desolder" with "solder"

N.B. These instructions are from last night, All the steps are in correct order
as well as the general information. The diagrams are from memory so components
may not be in the exact location indicated, but they will be very close.

LASTLY, Now that you have made the mods, you can use the warranty card to
light the Bar-B-Q Grill with.

####################################### DIAGRAMS #################################  

       BNC Connector             RF Board
   __ /                         /       internal metal frame
    |- ============================= /
   --  |                            \                         Logic Board
       |_____________________________|                       /
      ===============================================================

              SIDE VIEW OF RF-BOARD, METAL FRAME, LOGIC BOARD

                                               ---------------------------------
                                              |        L E G E N D
                                              |---------------------------------
       _____________________________          |   X1   BNC lead
      | @                      X5 @|          |   X2   BNC Sheild Lead
      |_                      --   |          |   X3   Power Switch Lead
     --_X1                   |  |  |          |   X4   Power Switch Lead
      |                       --   |          |   X5   Groundig Strap to RF Can
     ---X2             __          |          |  --
      |                --1         |          | |  |   RF Can Xtransformer with
      |                            |          |  --    ground wire soldered to it
      |                            |          |  _
      |         __                 |          | ( )    Channel Memory Capacitor
      - X3      --2                |          |  -
      - X4                         |          |  __
      | @                      @   |          |  --1   Plug from Squelch Control
      |____________________________|          |  __
                                              |  --2   Plug from Volume Contol
            TOP OF RF-BOARD                   |
                                              |   @    Threaded Stand-off
                                              |
                                              |   *    Phillips Screws
       ______________________________         |
      |*                     |    || |        |   0    Diode (vertical mounted)
      |                      |    || |        |
      |                      |____|| |        |   :    Solder Location of D9
      |                            | |        |        (where you move D11 to)
      |                             \|        |
      |                             *|        |
      |                             /|        |
      |                            | |        |
      |                            | |        |
      |                            | |        |
      |*                           | |        |
       ------------------------------         |
                                              |
     TOP OF INTERNAL METAL SUPPORT FRAME      |
                                              |_______________________________

       --------------------------------------------------------------
      |                                                            *|
      |                                                             |
      |                                                             |
      |                           _                                 |
      |                          ( )                                |
      |                           -                                 |
      |                                                             |
      |                                                             |
      |                                                             |
      |                D9  D10  D1                                  |
      |                  \  /   |                                   |
      |                  :00 <--                                   *|
      |_____________________________________________________________|

                 COMPONENT SIDE OF LOGIC BOARD

################################################################################

Here are the mods just as received from the MODS mail server

================================================================================

Date: 4 Apr 89 14:24:01 GMT
Subject: PRO-34 Scanner Modifications

    In  the  May 1989  edition  of  Popular  Communications  is a
"Letter  to the Editor" on the Radio Shack PRO-34 Scanner.  Below
is the text of that letter.

                  PRO-34 Scanner Modification

    In regard to the information  presented (March Issue)  on the
handheld Radio Shack PRO-34 scanner,  my own observations  on the
modifications have been:

1. To restore missing 800 MHz frequencies, remove D-11.

2. To add 66 to 88 MHz  (European Coverage),  install a diode at
   D-9.

3. D-10 must remain in place for full 800 MHz coverage.

4. If a diode is added at D-13 it cuts out aero band, also seems
   to affect 800 MHz channel spacing.

5. D-12 added dosen't seem to have any affect.

6. Only D-10 and D-11 are factory installed.

    I  wish to thank you  for a fine and informative  magazine. I
have had much reading enjoyment.

                             Sam S. Jones,
                             Rebel Antenna,
                             Falls Church, VA

--

Enjoy... Mark D. Copple
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