Pro-2004 vs PRO-2006

Pro-2004 vs PRO-2006

Post by John Bradle » Sat, 11 Mar 1995 21:12:26

 I have a PRO-2004 and have seen references to the PRO-2006. Is there
any functional difference between the two? I recall the PRO-2005 was
a PRO-2004 redone in surface mount components and a facelift but no
other differences.

.John Bradley


Pro-2004 vs PRO-2006

Post by Bob Parnass, AJ » Mon, 13 Mar 1995 05:11:56

  > I have a PRO-2004 and have seen references to the PRO-2006. Is there
  >any functional difference between the two? I recall the PRO-2005 was
  >a PRO-2004 redone in surface mount components and a facelift but no
  >other differences.

The PRO-2006 has 400 channels vs. the 300 channels in the stock
PRO-2004.  Also, the PRO-2006 scans and searches faster.

The PRO-2006 seems more sensitive than the PRO-2004.  A check
of the front end filter circuitry shows slight changes in component

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

                           - 1 -


            Copyright 1990, Bob Parnass, AJ9S

The Radio Shack PRO-2006 is a  400  channel,  wide  coverage
scanner  radio,  manufactured  in  Japan by General Research
Electronics.  It is the successor  to  the  PRO-2005  and  a
grandchild  of  the  PRO-2004,  the  super scanner which put
Radio Shack out in front of its competition in the base sta-
tion scanner market.1

The PRO-2006 is almost identical to  the  discontinued  PRO-
2005,   with   the   exception   that  the  PRO-2006  boasts
HyperscanTM, a catchy way of saying that it  scans  fast  --
about   26   channels/second   versus   the   PRO-2005's  16
channels/second rate.2 At about $400, the  PRO-2006  is  $20
cheaper  than  the  PRO-2005  was.   Both scanners are built
using surface mount components and  are  housed  in  a  gray
plastic cabinet.

                     Frequency Coverage

The PRO-2006 covers 25-520 and 760-1300 MHz,  except  for  2
gaps  in  the cellular telephone bands.  The two gaps in the
800 MHz range can be restored in all the  Radio  Shack  con-
tinuous  coverage  scanners by removing a diode.  Diode D502
is the culprit in the PRO-2005 and PRO-2006.

A matrix of diodes, attached to the  microprocessor's  input
port,  is  often  used  to configure radios for sale in dif-
ferent markets. The diode matrix  on  new  the  PRO-2006  is
located  on the vertical circuit board just behind the front
panel.  There are 2 diodes present, and holes drilled for  2

                       Lots of Memory


 1.  "Product Review: The Radio Shack PRO-2004 Programmable
    Scanner," by Bob Parnass AJ9S, in The Radio Enthusiast,
    February 1987, and Monitoring Times, March 1987.

 2.  "Product Review: The Radio Shack PRO-2005 Programmable
    Scanner," by Bob Parnass AJ9S, in The Radio Enthusiast,
    June 1989, and RCMA Journal, August 1989.

                           - 2 -

The PRO-2006 has the usual features that scanner buffs  have
come  to  expect:  individual channel lockouts, selectable 2
second rescan delay, an external speaker jack,  etc.  Casual
scanner users don't need 400 channels, but scanner hobbyists
can have those channels filled up in  no  time  flat,  espe-
cially with frequencies in the vast 225-400 MHz military air
band, and other federal government allocations.

With so many channels to program, one dreads the thought  of
a  power  failure, which could clear memory in a hurry.  Not
to worry, the PRO-2006 memory is backed up by a conventional
9  volt  alkaline  battery  (not  supplied), which should be
replaced every 6 months or so.

The 400 channels are divided into 10 banks  of  40  channels
each,  and  one can select or deselect any channel bank from
the scan list.  Individual channels can be locked out in the
customary  way, but the PRO-2006 maintains the handy feature
introduced in the PRO-2004, a  LOCKOUT  REVIEW.   Successive
depressions  of  this  key step through the locked out chan-

Scanners worth their keep  have  a  priority  feature,  with
channel  1  usually  designated  the  priority channel.  The
PRO-2006 is more flexible; any of the 400  channels  may  be
designated  the  priority channel.  When the PRIORITY key is
depressed, that channel will be sampled every 2 seconds, and
the radio will stay there if a signal is heard.

The PRO-2006 has two scan speeds,  which  measured  approxi-
mately  13  and  26 channels/second.  While scanning at high
speed, the PRO-2006 won't skip over weak signals  like  some
of the AOR-2515 scanners do.  Adding diode D501, situated at
an unmarked location between D502 and D503 sped up the  PRO-
2005 scan and search rates by 25%.  Adding the same diode in
the PRO-2006 has no effect on the scan or search rates.

It has been claimed that a PRO-2005 could  be  made  into  a
PRO-2006  by merely replacing the CPU clock crystal with one
of a higher frequency.   Don't  believe  it.   Changing  the
PRO-2005  clock speed would affect both the rescan delay and
the priority rate, and they would no  longer  be  2  seconds
long, as they are in the PRO-2006.

When programming a channel, the PRO-2006 firmware  sets  the
mode  automatically,  based on its idea of what mode is most
prevalent on that frequency.  This feature saves extra keys-
trokes,  and makes one appreciate the thought that went into
the design of this radio.  The default mode can be  overrid-
den easily, if need be, like to listen to a military mid-air
refueling operation in  the  225-400  MHz  range,  which  is

                           - 3 -

mainly populated with AM signals.


The SEARCH facility  found  on  most  programmable  scanners
allows  the entry of a pair of frequencies, then by pressing
a key, the radio searches frequencies between those  limits.
The  PRO-2006 allows for 10 pairs of limits!  These pairs of
limits are stored in their own memory, and don't use up  any
of  the  conventional  400  memory channels.  One can set up
several search pairs, for instance:

   - 46.610 - 46.970 MHz: cordless telephones

   - 144 - 148 MHz: the 2 meter ham band

   - 418.625 - 418.900: Drug Enforcement Administration

Another unique feature of the better Radio Shack  models  is
the  MONITOR key, which stops the search and stores the fre-
quency in  one  of  ten  special  monitor  memories.   These
memories  are  separate  from  the 400 main memory channels.
The search can be restarted from where it left off by strik-
ing the up or down arrow key.

The user can select the search direction (up or  down),  and
step  size  of  5, 12.5, or 50 kHz, although the PRO-2006 is
intelligent enough to select a default step  size  based  on
the  frequencies  being  searched.   As  on the PRO-2004 and
PRO-2005, there is a hidden step size of 30  kHz,  but  this
step size is only used in the cellular phone band after res-
toring full 800 MHz coverage.

The selected parameters are  displayed  on  the  LCD  panel,
smaller than the panel in the PRO-2004.

The DIRECT key allows one to start searching up or down from
whatever frequency is on the display.  Let's say the scanner
is in MANUAL mode, and set at  channel  26,  which  contains
460.100  MHz.  Striking the DIRECT then UP-ARROW keys starts
the PRO-2006 searching upwards from 460.100.  This is a nice

The  PRO-2006 contains a "window detector" circuit, which is
called  into  play  during a SEARCH operation.  This circuit
tries to detect when the radio is tuned close to the  center
frequency of a station, and prevents the search from halting
prematurely, off to the side of the signal.

                           - 4 -

The AFC (automatic frequency control) circuit of the Bearcat
800XLT  often  causes  a  search  of 850 MHz signals to halt
prematurely.  Even though the signal  sounds  on  frequency,
the display reads the wrong frequency.  Neither the PRO-2004
nor the PRO-2006 have this problem.

The PRO-2006 includes a SOUND SQUELCH,  resembling  the  VSC
circuit on the ICOM R-7000, which may be used during scan or
search operations.  With the sound squelch  enabled,  signi-
fied  by  a  red lamp above the pushbutton, the scanner will
skip over unmodulated signals.  This is handy  for  skipping
over  "birdies",  link  signals  with a constant carrier, or
baby monitors when baby is asleep.

The manual warns that the sound squelch  may  be  fooled  by
signals  with  low modulation, and skip over them.  The PRO-
2006 SOUND SQUELCH tries to detect the presence  or  absence
of  modulation  (not  human  speech),  so  unfortunately, it
thinks that noisy dead carriers, digital data  signals,  and
paging  tones are worth monitoring and will stop the scanner
to listen to them.

                      Taping Facility

A tape recorder can be connected to the TAPE phono  jack  on
the  rear  panel, which provides 600 mV of audio at a 10,000
ohm impedance.  An audio filtering  circuit  rolls  off  the
high  frequency  components before they reach the TAPE jack,
which makes it impossible to use it for picking off FM  sub-
carrier  signals.   In  addition  to a rear mounted external
speaker jack, there is a miniature  headphone  jack  on  the
front of the scanner.

The PRO-2006 lacks a COR (carrier  operated  relay)  output,
like  ICOM  R7000 and older Bearcat 300 have, which would be
useful for actuating a tape recorder.

                     Basic Performance

To evaluate sensitivity, the PRO-2006 was compared with it's
grandfather, the PRO-2004.  Since a signal generator was not
used, quantitative measurements could not be made.  Instead,
an  Antenna  Specialists AV-801 antenna was switched between
radios, signals from stations were compared by ear, and  the
results tabulated.

Simply put, the PRO-2006  proved  more  sensitive  than  the
PRO-2004 on all bands tested, and much more sensitive in the
850 MHz range.  The earlier PRO-2005 was also more sensitive

                           - 5 -

than  the  PRO-2004,  but both the PRO-2005 the PRO-2006 let
800 MHz trunked systems and cellular telephone conversations
bleed  through  while searching the 118 - 132 MHz commercial
aircraft band.  The 800 MHz interference was  heard  on  the
2005 and ...

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