Subject: Pro-2004 cellular mod
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.
*** File appended: more mods for the scanner
From: ewb
Newsgroups: rec.ham-radio
Subject: PRO-2004 MODS HERE THEY ARE !!!
Keywords:AGAIN !
Date: 12 Jan 89 14:34:39 GMT
Organization: Raytheon Co., Bedford, Mass.
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
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 !!!!!!!!!!!!!!!!!!!
SOURCE: The QRZ Windows Ham Radio CDROM |
