From philabs!prls!pyramid!hplabs!ucbvax!business.uwo.CA!MBramwel Fri Jan  6 09:25:27 EST 1989
Article 8568 of rec.ham-radio:
Path: philabs!prls!pyramid!hplabs!ucbvax!business.uwo.CA!MBramwel
>From: MBramwel@business.uwo.CA (Mark Bramwell 519 661-3714)
Newsgroups: rec.ham-radio
Subject: pro 2004 mods
Message-ID: <8901051631.AA06073@julian.uwo.ca>
Date: 5 Jan 89 15:16:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 34

Someone recently requested the mod for the Radio Shack PRO 2004
Here it is..........

PS:  How does one post to the packet list??

...........................................................................

The PRO-2004 scanner can be used to receive cellular telephone
conversations.  Originally, the scanner was able to receive in this
band, but at the last minute, it was decided to delete cellular
coverage from the PRO-2004.

The procedure to re-instate the cellular band is simple for anyone
with a pair of cutters, and a phillips screw-driver.

1.  Remove the four screws from the back of the radio, and slide
off the cover from the chassis.

2.  Turn the radio upside down.  You will find a metal box-like sub-
chassis in the center of the main chassis.  Remove the cover and
you will be looking at the CPU, a 64-pin integrated circuit.

3.  Examine the component side of this board, and you will find a row of
diodes and resistors.  On one end of the row you will find a diode
labeled  D-513.

4.  Clip the accessible end of D-513, and pry apart the ends so they
don't touch.  You have just restored cellular coverage to you scanner.

5.  If D-513 is not there, it may be located on the underside of
the circuit board.


*** Information was extracted from POPULAR COMMUNICATIONS Aug 1987.


From philabs!prls!pyramid!oliveb!ames!ncar!boulder!sunybcs!rutgers!elbereth.rutgers.edu!ron.rutgers.edu!ron Fri Jan  6 09:26:24 EST 1989
Article 8572 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!ames!ncar!boulder!sunybcs!rutgers!elbereth.rutgers.edu!ron.rutgers.edu!ron
>From: ron@ron.rutgers.edu (Ron Natalie)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Keywords: mods, scanner
Message-ID: <Jan.5.18.08.54.1989.130@ron.rutgers.edu>
Date: 5 Jan 89 23:08:56 GMT
References: <3749@druwy.ATT.COM>
Distribution: misc
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 10

Adjacent to the CPU chip there is a diode present in the modified
units know as D513.  D513 may or may not be marked depending on the
age of your unit.  D513 will be either next to D512 on the component
side of the board or it will be the on the solder side of the board
in the same place (i.e, next to the leads for D512).  In addition,
to get 30MHz steps when scanning 800 MHz (don't know why you'd want
that ;-).  Press the STEP key then press the RESET key right below
it.

-Ron


From philabs!prls!pyramid!voder!apple!rutgers!mailrus!ames!pasteur!ucbvax!ucdavis!vega.ucdavis.edu!u546025938ea Mon Jan  9 09:21:53 EST 1989
Article 8638 of rec.ham-radio:
Path: philabs!prls!pyramid!voder!apple!rutgers!mailrus!ames!pasteur!ucbvax!ucdavis!vega.ucdavis.edu!u546025938ea
>From: u546025938ea@vega.ucdavis.edu (0040;0000009724;0;340;141;)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Summary: An extra 100 channels
Message-ID: <3455@ucdavis.ucdavis.edu>
Date: 8 Jan 89 02:30:51 GMT
Sender: uucp@ucdavis.ucdavis.edu
Reply-To: u546025938ea@vega.ucdavis.edu (Steve Meyer)
Organization: University of California, Davis
Lines: 23

In addition to the cellular band, your RS PRO-2004 can also be modified for
another 100 channels of memory.  To do this:

     - Take the diode that was pulled for cellular coverage

     - Place it in an adjacent socket (I'm not /exactly/ sure of the #)

Presto!  You now have a 400-channel scanner.  If anyone is interested in the
exact socket number, please e-mail me (this info. was provided by a friend, who
is a PRO-2004 owner).  Also, this mod is available in Pop Comm.

     73,
     Steve N6QGG

Steve Meyer, N6QGG
Student, UC Davis

Internet: smmeyer@ucdavis.edu
Bitnet: smmeyer@ucdavis.bitnet
UUCP: {ucbvax, lll-crg}!ucdavis!smmeyer

P.S.: My apologies if this mod has already been posted; I just got back on the
net after an absense of over 5 weeks   :-)


From philabs!prls!pyramid!oliveb!ames!xanth!mcnc!gatech!udel!rochester!pt.cs.cmu.edu!cadre!pitt!cisunx!chain Wed Jan 11 08:50:18 EST 1989
Article 8688 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!ames!xanth!mcnc!gatech!udel!rochester!pt.cs.cmu.edu!cadre!pitt!cisunx!chain
>From: chain@cisunx.UUCP (Tom Link)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Message-ID: <14816@cisunx.UUCP>
Date: 10 Jan 89 03:58:45 GMT
References: <3455@ucdavis.ucdavis.edu> <2332@prdmgt.Columbia.NCR.COM>
Reply-To: chain@unix.cis.pittsburgh.edu (Tom Link)
Organization: The Zets
Lines: 35

In article <2332@prdmgt.Columbia.NCR.COM> flake@prdmgt.UUCP (joe flake) writes:
>In previous article:
>>your RS PRO-2004 can also be modified for another 100 channels of memory
>>Presto!  You now have a 400-channel scanner.
>
>I've seen several references to this mod.  All omit the details of how
>the keyboard and scanning functions work AFTER the mod.  Specifically,
>a 2004 banks memorys as 10 banks of 30 memories.  You can enable/disable
>scanning a bank by hitting a single digit during scan operation.  Where
>do the new memories go?  Does it become 10 banks of 40 memories, or do
>you now have 3.3 new banks of 30 memories or what?

Info is taken from December 1988 issue of Popular Communications:

the diode # to be added is D510 (if there's a jumper present - remove it)
polarity should point towards the cpu chip.

now instead of 30 channels in each of the 10 memories banks you'll
have 40 channels.

I read some other mods in other issues of Pop com and in 73 i'll
post the after i find them if nobody beats me to it

73 from a non-ham (hopefull a novist soon -- just need the code)
posting his his first post and not knowing if it will work.

-- 
| Tom Link, University of Pittsburgh Computer Science
| BITNET: chain@pittunx
| USENET: ...!pitt!cisunx!chain
| ARPANET: chain%unix.cis.pittsburgh.edu@vb.cc.cmu.edu
| CC-NET: chain::cisunx
| UUCP: {decwrl!allegra,bellcore,cadre,psuvax1}!pitt!cisunx!tjw
| AT&T: 1 (412) 731-6296
| US-MAIL : 310 Surrey Place, Pittsburgh PA 15235-5056, USA


From philabs!prls!pyramid!oliveb!ames!mailrus!ncar!noao!asuvax!nud!xroads!coffin Wed Jan 11 09:14:44 EST 1989
Article 8711 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!ames!mailrus!ncar!noao!asuvax!nud!xroads!coffin
>From: coffin@xroads.UUCP (Chris Coffin)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Message-ID: <539@xroads.UUCP>
Date: 10 Jan 89 14:06:47 GMT
References: <3455@ucdavis.ucdavis.edu> <2332@prdmgt.Columbia.NCR.COM>
Reply-To: coffin@xroads.UUCP (Chris Coffin)
Organization: Crossroads, Phoenix, AZ 85046
Lines: 38

joe flake (flake@prdmgt.UUCP) writes:
> In previous article:
> >your RS PRO-2004 can also be modified for another 100 channels of memory
> >     {details}
> >Presto!  You now have a 400-channel scanner.
> [deleted verbage]
> scanning a bank by hitting a single digit during scan operation.  Where
> do the new memories go?  Does it become 10 banks of 40 memories, or do
> you now have 3.3 new banks of 30 memories or what?
> 
> Any reasons NOT to make the mod other than the obvious warranty issues?
> It seems too good to be true!
> 

I have made the 850MHz, 400 channel, and increased scanning
speed mods to my PRO-2004. You end up with 10 banks of 40
channels each. After doing the mod, you have to reprogram all
your frequencies in again. (no real surprise here). It all works
just fine and dandy! Yes, it is too good to be true, but it is
true and it works great!

Chris

this
is
food
to
fatten
up
the
line
eater


-- 
\  /  C r o s s r o a d s  C o m m u n i c a t i o n s
 /\   (602) 941-2005 300|1200 Baud 24 hrs/day
/  \  hplabs!hp-sdd!crash!xroads!coffin


From philabs!prls!pyramid!decwrl!hplabs!hp-sdd!ncr-sd!ncrlnk!ncrwic!encad!enprt!hburford Wed Jan 11 09:16:10 EST 1989
Article 8715 of rec.ham-radio:
Path: philabs!prls!pyramid!decwrl!hplabs!hp-sdd!ncr-sd!ncrlnk!ncrwic!encad!enprt!hburford
>From: hburford@enprt.Wichita.NCR.COM (Harry Burford)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Message-ID: <433@enprt.Wichita.NCR.COM>
Date: 10 Jan 89 13:48:41 GMT
References: <3455@ucdavis.ucdavis.edu> <2332@prdmgt.Columbia.NCR.COM>
Reply-To: hburford@enprt.UUCP (Harry Burford)
Organization: NCR Corporation, Wichita, Kansas
Lines: 24

In article <2332@prdmgt.Columbia.NCR.COM> flake@prdmgt.UUCP (joe flake) writes:
|>In previous article:
|>>your RS PRO-2004 can also be modified for another 100 channels of memory
|>>
|>>     {details}
|>>
|>>Presto!  You now have a 400-channel scanner.
|>
|>I've seen several references to this mod.  All omit the details of how
|>the keyboard and scanning functions work AFTER the mod.  Specifically,
|>a 2004 banks memorys as 10 banks of 30 memories.  You can enable/disable
|>scanning a bank by hitting a single digit during scan operation.  Where
|>do the new memories go?  Does it become 10 banks of 40 memories, or do
|>you now have 3.3 new banks of 30 memories or what?
|>Joe Flake, N4BGQ

YES, after the channel mod. you will have 10 banks of 40 channels each.
your keyboard labels for the channel banks becomes useless.
hb
-- 
Harry Burford - NCR E & M Wichita, Printer Engineering
PHONE:   316-636-8016                 Amateur Call:  KA0TTY
FAX:     316-636-8889
C-Serve: 76367,151                    Harry.Burford@Wichita.NCR.COM


From philabs!prls!pyramid!decwrl!labrea!agate!ucbvax!ucdavis!vega.ucdavis.edu!u546025938ea Thu Jan 12 08:39:07 EST 1989
Article 8738 of rec.ham-radio:
Path: philabs!prls!pyramid!decwrl!labrea!agate!ucbvax!ucdavis!vega.ucdavis.edu!u546025938ea
>From: u546025938ea@vega.ucdavis.edu (0040;0000009303;0;340;141;)
Newsgroups: rec.ham-radio
Subject: PRO-2004 modification
Summary: 400 channel mod.
Message-ID: <3476@ucdavis.ucdavis.edu>
Date: 11 Jan 89 07:18:25 GMT
Sender: uucp@ucdavis.ucdavis.edu
Reply-To: u546025938ea@vega.ucdavis.edu (Steve Meyer)
Organization: University of California, Davis
Lines: 49

Due to the fact that several people have requested this information, I am
posting the 400-channel mod. to the Radio Shack PRO-2004.

This information was relayed to me by a friend in Los Angeles, who read it
to me verbatim out of _Popular Communications_, Dec. 1988.  Neither he
(a PRO-2004 owner) nor I (not an owner) have tried this mod.


     Take the diode out of 513 (for cellular coverage) and,
     while observing polarity, replace in socket 510.

     NOTE: apparantly, on some PRO-2004's (not most) there is
           a jumper or solder jumper across the two D510
           mounting holes.  It is possible that this is on
           the other (bottom) side of the sub-assembly board.
           In any event the jumper, should it exist, must be
           carefully removed with a desoldering tool.

     Be sure to handle the sub-assembly board and cable connector
     CN-501 with TLC, since even the slightest damage or minor
     crack in the board will result in a scanner good for use
     as a boat anchor.

   LOCATION: the diode is located on PC-3, near restart switch SW-101

This modification will now provide the user with 400 channels of scanner
memory.  These will be divided into 10 banks of 40 channels, thus making the
keypad notation inaccurate.  This is the only operational effect the mod.
has.

OTHER DIODES OF INTEREST:    D-510   400 channel mod.
                             D-512   Installed on Australian/European versions
                             D-513   Cellular lockout
                             D-514   Supposedly increases scan rate above
                                     16 channels/second
                             D-515   In-factory install (?)


I hope this helps, and good luck with it.

     73, Steve N6QGG

Steve Meyer, N6QGG
Student, UC Davis

Internet: smmeyer@ucdavis.edu
Bitnet: smmeyer@ucdavis.BITNET
UUCP: {ucbvax, lll-crg}!ucdavis!smmeyer
Packet: n6qgg @ kg6xx-1


From philabs!prls!pyramid!decwrl!labrea!rutgers!rochester!pt.cs.cmu.edu!cadre!pitt!cisunx!chain Thu Jan 12 09:38:25 EST 1989
Article 8764 of rec.ham-radio:
Path: philabs!prls!pyramid!decwrl!labrea!rutgers!rochester!pt.cs.cmu.edu!cadre!pitt!cisunx!chain
>From: chain@cisunx.UUCP (Tom Link)
Newsgroups: rec.ham-radio
Subject: Re: PRO-2004 Mods
Summary: summery of Mods with some added -- S-METER -- FASTER SCAN
Message-ID: <14852@cisunx.UUCP>
Date: 11 Jan 89 18:16:29 GMT
References: <14816@cisunx.UUCP>
Reply-To: chain@unix.cis.pittsburgh.edu (Tom Link)
Organization: The Zets
Lines: 84

In article <14816@cisunx.UUCP> chain@unix.cis.pittsburgh.edu (Tom Link) writes:
>I read some other mods in other issues of Pop com and in 73 i'll
>post the after i find them if nobody beats me to it

Well, nobody beat me to 'em so I'm back

here a list of the diode functions as printed in Aug 1988 edition of 73
by KB6LCN

d-510  in circut      - scanner will have 400 memories (10 x 40)
       not in circut  - scanner will have 300 memories (10 x 30)

d-512 in circuit - it will step  30 kHz from 825-844.995 and 870-889.995
      removed    - "   "    "   12.5 "  "      "          "      "a

d-513 in circut  - will not scan 825-844.995 MHz or 870-889.995 MHz
      removed    - will scan all of 800 MHz band

d-514 in circuit     - scanning rate increases to 20 channels per second
      not in circut  - scanning rate in 19 ch/sec (alt 8 ch/sec)

!!!! WATCH POLARITY !!!!

in Aug 1987 Popular Communications Bill Cheek gives the bet details to 
bring back the lost 800 MHz Freqs. and poinsts out that in the replaced
bands the defalt skip rate for a search is 30 MHz however if change 
it with the step key you need to press the RESET key on the front
keypad to return to 30 MHz increment step.  (RESET is to to be confused 
with the RESTART button on the rear of the unit).

he also gives modifications for an S-meter

S-METER

1 - locate transister q-9 (far frount right area of the radio, just 
    under the sloaping front panel.

2 - drill a 1/4" hole in the rear chassis of the radio

3 - install a RCA jack in this hole

4 - Install on lead of a .10-uF ceramic disc capacitor to the center 
    lug of the RCA jack and the other lead to ground lug of the RCA 
    jack 

5 - clip off all but 1/4" of leads of a 10-K ohm resistor.  Carefully,
    soder one lead to the collector (center lead) of q-9.
    !!! pretin all leads and use a low watt iron with sharp tip 

6 - solder a 12" wire to the free end of the 10-K resistor.  Slip a 1"
    section of insulated tubing over resistor and wire to prevent 
    shorting.

7 - connect free end of the wire to the center lug of the RCA jack

8 - connect a voltmeter capable of reading between 1 and 3 volts,
    DC (digital or analog to a RCA plug.  red wire to center, and
    black wire to the shell.  shielding in not needed.

connecting the rca jack and plug will now give you a measurement
of the recievers intermediate frequency automatic gain control (IF AGC)
the auther said the the range will be between + 1.87 volts DC with
no signals present to +2.6 volts DC for a strong signal.  he also 
suggested that a digital voltmeter with 2 or three decimal places
gave better resolution.

I ordered the scanner when Radio Shack's catalog announced it
and got it as soon as it came in an etirnity later.  I restored the 
lost 800 MHz freq about a year and a half ago and have not found any 
problems.  I'll probable do the other mods this weekend.

If any else knows mods let us know.

73 from a hopefully soon to be novist trying to study code

-- 
| Tom Link, University of Pittsburgh Computer Science
| BITNET: chain@pittunx
| USENET: ...!pitt!cisunx!chain
| ARPANET: chain%unix.cis.pittsburgh.edu@vb.cc.cmu.edu
| CC-NET: chain::cisunx
| UUCP: {decwrl!allegra,bellcore,cadre,psuvax1}!pitt!cisunx!tjw
| AT&T: 1 (412) 731-6296
| US-MAIL : 310 Surrey Place, Pittsburgh PA 15235-5056, USA


From philabs!linus!raybed2!ewb Mon Jan 16 09:04:26 EST 1989
Article 8822 of rec.ham-radio:
Path: philabs!linus!raybed2!ewb
>From: ewb@raybed2.UUCP (EUGENE BALINSKI)
Newsgroups: rec.ham-radio
Subject: PRO-2004 MODS  HERE THEY ARE !!!
Keywords: AGAIN !
Message-ID: <1255@raybed2.UUCP>
Date: 12 Jan 89 14:34:39 GMT
Organization: Raytheon Co., Bedford, Mass.
Lines: 87


    I guess it's time to post this article again. As always do these mods
at your own risk. I assume no responsibility.  73 & good listening
                                               
                                              Gene WA1UXA






    In response to numerous inquiries I am posting a short overview of the 
mods to the Radio Shack PRO-2004 scanner. First, all mods are done at
your own risk. I assume no responsibility. I do not know what effect they
(the mods) will have on any warranty, however I would think they would
probably void it. Also, one of the mods restores coverage of the cellular
phone frequencies. It is ILLEGAL TO LISTEN TO CONVERSATIONS IN THIS BAND !
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Therefore my supplying info to you does NOT in any way constitute an invitation
to break the law. You are on your own! 

    These mods are detailed in the following articles:
a) POPULAR COMMUNICATIONS AUG 87, PP 18-20
b) MONITORING TIMES OCT 87, P 53
c) MONITORING TIMES DEC 87,P 60
I suggest strongly that you obtain the back issues and read through the letters
or articles. I also suggest you subscribe to the mags. They supply a lot of    
great info and freq lists. Now the mods.
 
1) Restoring 870 MHz coverage.
First treat the radio as if it were CMOS, that is make sure you and it have no
built up static charges. UNPLUG THE RADIO FROM THE AC OR DC POWER SOURCE AND
ANTENNA !!!!!!!! Take the radio out of the case by removing the 4 screws on 
the back. Carefully invert the radio. Locate a box-like sub-circuit. It's 
near the switch marked "restart". The sub-circuit should be marked PC-3.
Carefully pry off the cover of the metal box. Inside there will be a 64 pin dip
IC. This is the radio CPU. Be careful not to touch or short out any leads on
the chip. Near the chip there will be a row of diodes marked D-502 to D-515.
If D-513 is present, cut one lead, separate it so they will not touch, and 
magic, 870 Mhz is restored. If D-513 is not there and you still do not have
870 coverage, then a little more work is in order. Locate the 9 pin connector
"CN-501". Carefully remove it from the sub-circuit. Unscrew the screws holding
PC-3 to the main chassis. Carefully invert the sub-circuit board (PC-3).
Locate the one lone component on that side of the board. If it is a diode,
as it should be, then cut one lead and separate them as above. Re-install the
sub-circuit with the screws on to the main chassis. Reconnect the 9 pin 
connector. Do NOT put the cover back on just yet ?!  

                     2&3)   400 CHANNEL and SPEED MOD !
       On the top of the sub-circuit board, locate the slot for D-513. Count
backwards from there until you get to the space for D-510. Install a diode
at D-510 in the same polarity as the rest of the diodes. There, you now 
have 400 channels instead of 300 ! Now install a diode at D-514 and you have 
increased the scan speed to 20 channels/sec from 16 ch/sec. Carefully re-
assemble the metal box. Make sure everything else is as it should be.
RE-invert the radio so it is right side up. 
 
                        4)  THE SQUELCH MOD !!
    Now, locate a sub-circuit box under the sloping front panel. It should 
have many alignment holes in the top. Pry the cover off very carefully.
Locate IC-2 in the left side of the pc board. It should be marked IC-
10420. Locate R-148, a 47 K ohm resistor between pins 12 and 13. 
Cut a lead of this resistor, But be sure to leave enough lead on both
sides of the cut to solder to. Patch in a 100K ohm resistor. Make sure
there are no solder balls or short circuits. Now your squelch will operate
more smoothly.      
           
         Again, I STRONGLY suggest you obtain the above mentioned
magazines for more details. Addresses appear below. Please ignore any 
mis-spellings, mis grammer, etc. Good luck and good listening !!!
                                                     73
                                                 Gene WA1UXA

PS, make sure you re-install the metal cover and re-install the radio in the
case !!!!!!!!!!!!!!!!!!


Addresses:     Popular Communications
               76 N Broadway
               Hicksville, NY. 11801
                          
              Monitoring Times
              140 Dog Branch Rd
              P.O. Box 98
              Brasstown, NC. 28902

                          Standard disclaimer applies !!!!!!!!!!!!!!!!!!!


From philabs!prls!pyramid!amdahl!bnrmtv!brandt Sun Mar 19 14:02:03 EST 1989
Article 10444 of rec.ham-radio:
Path: philabs!prls!pyramid!amdahl!bnrmtv!brandt
>From: brandt@bnrmtv.UUCP (Adrian Brandt)
Newsgroups: rec.ham-radio
Subject: Re: Another PRO-2004 mods request
Summary: Here are some Pro-2004 modifications
Message-ID: <5101@bnrmtv.UUCP>
Date: 16 Mar 89 18:45:27 GMT
References: <15835@cup.portal.com>
Organization: Bell Northern Research, Mtn. View, CA
Lines: 51

In article <15835@cup.portal.com>, Jay@cup.portal.com (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...


From philabs!prls!pyramid!oliveb!ames!haven!purdue!iuvax!silver!commgrp Wed Mar 22 09:13:52 EST 1989
Article 10541 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!ames!haven!purdue!iuvax!silver!commgrp
>From: commgrp@silver.bacs.indiana.edu
Newsgroups: rec.ham-radio
Subject: Re: Another PRO-2004 mods request
Message-ID: <12600047@silver>
Date: 21 Mar 89 20:48:00 GMT
References: <15835@cup.portal.com>
Organization: Indiana University CSCI, Bloomington
Lines: 59
Nf-ID: #R:cup.portal.com:-1583500:silver:12600047:000:2495
Nf-From: silver.bacs.indiana.edu!commgrp    Mar 21 15:48:00 1989




In article <15835@cup.portal.com>, Jay@cup.portal.com (Jay M Novello)
requests PRO-2004 mods.

[posted mods deleted]

>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.

previously posted by <??>:
] Turbo scan for the 2004 ??? Yes !! Someone has realized that if you 
] replace the present 7.37 MHz ceramic resonator CX501, with a 10.7 MHz
] ceramic resonator it really boosts the scan/search speed! The present
] resonator is soldered between pins 29 and 30 of the CPU (IC-503). 
] Rumor has it that a 10.00 MHz computer xtal will work just fine. 
] Note: The effect of the speed mod on weak signal performance is 
] presently unknown.

The resonator is for the CPU clock oscillator.  Jacque KA9FJS confirms 
that the mod works with an ordinary 10 MHz computer crystal ($1 at 
hamfest) but reports a possibly-undesirable side effect:  Increasing 
the clock rate _decreases_ the resume-scan delay time.  Jacque says:  
"The manual says delay is 2 seconds; with mod, delay is <1 second.  
Painful if a channel is filled with slow responders."  He reports no 
detection problems at the increased scan rate.

>Also, by soldering a diode in... 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...
  
PRO2004 keyboard template for 400-channel modification, showing 
new channel-bank contents:

         +-----------+-----------+-----------+
         |     1     |     2     |     3     |
         |           |           |           |
         |   1 - 40  |  41 - 80  |  81 - 120 |
         +-----------+-----------+-----------+
         |     4     |     5     |     6     |
         |           |           |           |
         | 121 - 160 | 161 - 200 | 201 - 240 |
         +-----------+-----------+-----------+
         |     7     |     8     |     9     |
         |           |           |           |
         | 241 - 280 | 281 - 320 | 321 - 360 |
         +-----------+-----------+-----------+ 
         |     0     |           |           |
         |           |     .     |   CLEAR   |
         | 361 - 400 |           |           |
         +-----------+-----------+-----------+
--

Frank     W9MKV @ K9IU     reid@gold.bacs.indiana.edu
{inuxc,rutgers,uunet!uiucdcs,pur-ee}!iuvax!silver!commgrp
"Hams across the water, hams across the sky."


From philabs!prls!pyramid!oliveb!apple!bloom-beacon!tut.cis.ohio-state.edu!ucbvax!ucsd!rutgers!att!ihuxz!parnass Mon Mar 27 09:43:31 EST 1989
Article 10629 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!apple!bloom-beacon!tut.cis.ohio-state.edu!ucbvax!ucsd!rutgers!att!ihuxz!parnass
>From: parnass@ihuxz.ATT.COM (Bob Parnass, AJ9S)
Newsgroups: rec.ham-radio
Subject: A carrier operated light for the PRO-2004 [repost]
Message-ID: <4265@ihuxz.ATT.COM>
Date: 25 Mar 89 12:33:46 GMT
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 91


Several PRO-2004 owners have asked for a repost of this article:

x-------------- CUT HERE --------------------------------------x


       A CARRIER OPERATED LIGHT FOR THE PRO-2004 SCANNER

                     by Bob Parnass, AJ9S

   The July 1988 issue of Monitoring Times suggested that it
   may  be  easy  to add an S-meter to the Radio ShackO PRO-
   2004 scanner:

    "...But adding an "S" meter is even easier  than  previ-
   ously  thought.   Pin  10 on the IF amplifier (IC1) is an
   "S" meter output.   With  the   proper  bridge  or  meter
   buffer/amplifier an "S" meter is reality...."

   Brace yourself for disappointment - the  integrated  cir-
   cuit  mentioned  in  the  article  is used for WBFM only.
   Despite the internal IC  block  diagram  in  the  service
   manual,  pin  10  on  my PRO-2004 is useful as an S-meter
   output only when the radio is in the WBFM mode.

   Between pin 10 and ground, I placed a 10,000 ohm resistor
   in  series  with  a  250 microamp meter for a simple test
   setup.  The meter read  full  scale  on  strong  signals.
   With  no  signal at all, the meter read about 70% of full
   scale.  When the mode is set to AM or NBFM, the meter was
   always at zero.

   One could add a bridge circuit here,  but  this  metering
   point is of limited utility.


                      Add a Light Instead

   With a room full of functioning scanners, it's  difficult
   to  determine  quickly  which  radio is "talking."  I use
   separate external speakers on each radio, and the spatial
   separation helps.

   In addition to "hearing" which radio is active, I like to
   "see"  which radio is active, and carrier operated lights
   are effective at providing such visual cues.  The idea is
   to  illuminate a lamp when a signal opens the squelch.  A
   small yellow light emitting diode (LED, another Bell Labs
   invention) is well suited to this purpose.  The following
   modification works well on all PRO-2004 modes.

   To add a COR light to the PRO-2004, make use of the "scan
   control" pin (pin 13) on IC2, the TK10420 IC.  Pin 13 has
   voltage present only when a  signal  is  detected.   This
   chip contains the IF, detector, limiter, and squelch cir-
   cuitry for NBFM.

   If you tremble with an electric drill in your hands, read
   no  further.   The  LED  can  be  mounted in a small hole
   drilled through the plastic  front  panel,  just  to  the
   right of the headphone jack.

   Electronically, the circuit is simple.   The  voltage  at
   pin 13 is not enough to drive the LED directly, so a gen-
   eral purpose NPN transistor (e.g., a 2N2222) can be  used
   as a solid state switch.

      - Pin 13 of IC2 is connected to  the  transistor  base
        through a 10,000 ohm resistor.

      - The emitter is grounded.

      - The collector is connected through a 1000 ohm resis-
        tor  to one end of an LED.  This resistor limits the
        LED current to about 13 milliamps.

      - The other end of the LED is connected to one contact
        on  the  rear  of the PRO-2004's on/off, volume con-
        trol.  This furnishes about 14  VDC  unregulated  to
        the  circuit.  The back of the on/off switch has two
        contacts.  Use the one with the brown wire connected
        to  it,  as  this  contact  is  only "live" when the
        scanner is turned on.

   I mounted the 2 resistors and transistor on  a  small  PC
   board,  which  I fastened to the PRO-2004 chassis using a
   metal standoff.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Bob Parnass AJ9S,  AT&T Bell Laboratories  -  att!ihuxz!parnass - (312)979-5414