THE RADIO SHACK PRO-2005 PROGRAMMABLE SCANNER

                    by Bob Parnass, AJ9S

  Manufactured in Japan by  General  Research  Electronics,
  the  Radio Shack PRO-2005 is a 400 channel, wide coverage
  scanner radio, incorporating NBFM, WBFM,  and  AM  modes.
  It  is  the  successor to the PRO-2004, the super scanner
  which put Radio Shack out in front of its competition  in
  the base station scanner market.

  The 2005 is basically a 400 channel PRO-2004, built using
  surface  mount  components, and housed in a smaller pack-
  age.


                     Frequency Coverage

  Radio Shack's last minute  decision  to  remove  cellular
  telephone frequency coverage from the PRO-2004 caused a 7
  week delay in its introduction.  The PRO-2005 appeared in
  the  stores  promptly  on  the heels of the 2004 closeout
  sale.  Both the PRO-2004 and PRO-2005  cover  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 either scanner by clipping a diode.

  A matrix of  diodes,  attached  to  the  microprocessor's
  input port, is often used to configure radios for sale in
  different markets. The diode matrix on new  the  PRO-2005
  is  located on the vertical circuit board just behind the
  front panel.  There  are  2  diodes  present,  and  holes
  drilled for 2 more.


                       Lots of Memory

  The PRO-2005 has the usual features  that  scanner  buffs
  have   come  to  expect:   individual  channel  lockouts,
  selectable rescan delay, an external speaker  jack,  etc.
  But,  the  400  channel  capacity  of  the  PRO-2005 sets
  another an industry record, just as the 300 channel  PRO-
  2004  did!  Casual scanner users may scoff at the useful-
  ness of having so many channels, but seasoned monitorists
  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-2005  memory  is  backed  up  by  a











                          - 2 -



  conventional 9 volt alkaline battery (not supplied).  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-2005 maintains the
  handy feature  introduced  in  the  PRO-2004,  a  LOCKOUT
  REVIEW.   Successive depressions of this key step through
  the locked out channels.

  Scanners worth their keep have a priority  feature,  with
  channel  1  usually designated the priority channel.  The
  PRO-2005 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-2005 has two scan speeds, approximately 8 and  16
  channels/second, although one would probably use the fas-
  ter speed in most instances.  This is the same  speed  as
  the  stock  PRO-2004,  as  measured  by your reviewer.  A
  diode could be added to  the  PRO-2004  diode  matrix  to
  speed up the scan and search rates by 25%.  The provision
  for extra diodes in the diode matrix  makes  one  hopeful
  that  the  same speedup trick can be applied to the newer
  PRO-2005.

  When programming a channel, the  PRO-2005  firmware  sets
  the mode automatically, based on its idea of what mode is
  most prevalent on that  frequency.   This  feature  saves
  extra  keystrokes,  and  makes one appreciate the thought
  that went into the design of  this  radio.   The  default
  mode can be overridden easily, if need be, like to listen
  to a NBFM satellite in the 225-400 MHz  range,  which  is
  mainly populated with AM signals.


                          Searching

  The SEARCH facility found on most  programmable  scanners
  allows the entry of a pair of frequencies, then by press-
  ing a key, the radio searches frequencies  between  those
  limits.   The  PRO-2005  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












                          - 3 -



     - 30.01-30.56, 32-33, 36-37 MHz: US Govt

  Another unique feature is the MONITOR  key,  which  stops
  the search and stores the frequency 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 striking 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-
  2005 is intelligent enough to select a default step  size
  based  on the frequencies being searched.  As on the PRO-
  2004, there  is  a  hidden  step  size  of  30  kHz,  but
  apparently  this step size was disabled when the cellular
  telephone frequency coverage was removed.

  The selected parameters are displayed on the  LCD  panel,
  smaller  than the panel in the PRO-2004.  Search speed is
  switchable between slow and fast, with fast search  being
  about   14   increments/second   (versus   12   for   the
  Uniden/Bearcat 800XLT).  For a 12.5 kHz  increment,  this
  translates  to 11.2 MHz/minute (versus 9.6 MHz/minute for
  the 800XLT).

  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-2005 searching upwards from  460.100.
  This is a nice feature.

  The  PRO-2005 contains a "window detector" circuit, which
  is called into play during a SEARCH operation.  This cir-
  cuit 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.

  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.  Nei-
  ther the PRO-2004 nor the PRO-2005 have this problem.

  The PRO-2005 includes a SOUND SQUELCH, resembling the VSC
  circuit on the Icom R-7000, which may be used during scan
  or  search  operations.   With  the  the  sound   squelch
  enabled,  signified  by  a red lamp above the pushbutton,
  the scanner will skip over unmodulated signals.  This  is
  handy for skipping over "birdies", or link signals with a
  constant carrier.











                          - 4 -



  The manual warns that the sound squelch may be fooled  by
  signals  with  low  modulation,  and skip over them.  The
  PRO-2005 SOUND SQUELCH tries to detect  the  presence  or
  absence  of  modulation  (not  human  speech),  so unfor-
  tunately, 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  pick-
  ing  off  FM  subcarrier  signals.  In addition to a rear
  mounted external speaker jack, there is a miniature head-
  phone jack on the front of the scanner.

  The PRO-2005 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-2005 was  compared  with
  it's  father, 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  com-
  pared by ear, and the results tabulated.

  Simply put, the PRO-2005 proved moderately more sensitive
  than the PRO-2004 on most bands tested, and just slightly
  more sensitive on a few bands.  The cost one pays for the
  2005's  increased  sensitivity  is  having to put up with
  hearing 800 MHz trunked systems  and  cellular  telephone
  conversations  while  searching the 118 - 132 MHz commer-
  cial aircraft band.  The 800 MHz interference  was  heard
  only  on the 2005, not the 2004.  Other than that, inter-
  modulation  interference  from   paging   affected   both
  scanners to the same degree, and on the same frequencies.

  Although both the 2004 and 2005 can suffer the effects of
  intermod,  they are much more immune than the overly sen-
  sitive, image laden Bearcat 800XLT.  The PRO-2005  has  a
  10 dB attenuator, operable by a slide switch on the rear.













                          - 5 -



  The up conversion design of  both  the  ICOM  R-7000  and
  Radio Shack PRO-2005 allows use of a very high IF (inter-
  mediate frequency), which  helps  avoid  image  problems.
  The  PRO-2004 owner's manual contains a frequency alloca-
  tion chart and a section on images.  This section appears
  in  the  manuals  for  other  Radio Shack models, and was
  thoughtlessly thrown into the 2005 manual.  It babbles on
  about  images being 21.4 MHz away from the real frequency
  -- true for simpler models, but not so for the PRO-2005.

  The audio  output  quality  is  good,  although  the  top
  mounted  speaker  directs  the  sound at the ceiling, but
  adding an external speaker would allow the  sound  to  be
  directed at the user.

  Unfortunately, the audio level of AM signals is  somewhat
  below that of NBFM signals, requiring a different setting
  of the volume control.  When scanning both  AM  and  NBFM
  modes,  one  has  to  find  a  compromise position of the
  volume control.

  The PRO-2005 squelch control has a wee bit too much  hys-
  teresis, a trait inherited from its ancestors.  It's like
  having too much play in a car's steering wheel, or  back-
  lash  in  a gear set.  This hysteresis forces one to keep
  the squelch at a tighter setting, missing weaker  signals
  when scanning or searching.  It's not as sloppy as in the
  early PRO-2004s.  I've successfully eliminated this prob-
  lem  completely  by  replacing  a  single resistor on the
  800XLT, as well as the PRO-2002, PRO-2003,  PRO-2004  and
  PRO-24 scanners.


                   Mechanical Construction

  The PRO-2005 is lighter than the 2004.  It is enclosed in
  a  gray  plastic cabinet, with a plastic front panel.  If
  one is going to pay $420, one deserves to own some metal,
  but  several  stages are internally shielded in their own
  metal compartments.  The entirely plastic cabinet of  the
  older  PRO2003  allowed  wideband noise to radiate out of
  the scanner and into nearby shortwave receivers.

  The PRO-2005 vertical front panel is an advancement  over
  the  sloping  panel  of  the 2004.  Now you can stack the
  scanner on top of other equipment and  see  the  controls
  without standing up.  If sitting directly on a table, two
  hinged plastic feet, padded with rubber bumpers, can fold
  out  from  under  the  front of the radio to tilt it at a
  good viewing angle.












                          - 6 -



  There is a single BNC antenna connector on  the  rear  of
  the  PRO-2005,  and  a single telescoping antenna is sup-
  plied.

  Internal construction  is  excellent,  and  the  internal
  shielding  is  commendable.  Interstage shielding is very
  important in a wide band receiver,  to  prevent  it  from
  "hearing  itself", an undesirable phenomena which results
  in birdies.  The PRO-2005 owner's manual lists the birdie
  frequencies.   The  shielding  is much better in the PRO-
  2005 than in the 800XLT, which uses no  shielding  around
  the  800  MHz  converter stage, and probably accounts for
  some of the birdies in the Bearcat.

  Frequencies and other indicators are displayed on a back-
  lit  LCD (liquid crystal display) panel, and the level of
  backlighting can be dimmed by a pushbutton switch.

  Vision impaired scanner buffs will appreciate the conven-
  tional  raised  rubber  keyboard  in  the PRO-2005, which
  replaced the flat  membrane  keyboard  in  the  PRO-2004.
  Only moderate pressure is required for actuation, and key
  depressions are confirmed by a mild "beep" audio tone.

  The PRO-2005 is the right size to fit under the dashboard
  of  intermediate sized cars.  Although it can be operated
  on 12 VDC, neither  a  mobile  power  cord  nor  mounting
  bracket  are  provided.   These  items were included with
  earlier, pre-PRO-2004 Radio Shack models.  The  AC  power
  cord  is  not detachable, and would have to be bundled up
  to keep it out of the way in a mobile installation.


                       Owner's Manual

  The user manual is outstanding compared with the fold out
  sheet furnished with Uniden scanner.

  A single page frequency allocations  chart  is  included,
  but  is not current.  There is no schematic.  Thankfully,
  detailed service manuals for  Radio  Shack  scanners  are
  usually available for $7.50 or $10.00.

  The PRO-2005 is warranted for 1 year, which  is  reassur-
  ing.


                       What's Missing?

  So with all these neat features, what's missing from  the
  PRO-2005?   A  "search  and store" mode, like that on the











                          - 7 -



  ICOM R7000 and older Bearcat 250 would have been nice.  A
  lighted  keyboard  and a signal strength meter would also
  be welcome, as would a mobile mounting  bracket  and  SCA
  output jack.


                           Summary

  If all one wants is a scanner to monitor local police and
  fire, there are certainly cheaper and simpler models than
  the PRO-2005.   This  scanner  is  for  those  who  enjoy
  actively  exploring  voice  communications in the VHF/UHF
  spectrum.  If you already own a PRO-2004 and  have  added
  the  diode  to expand it to 400 channels, there is little
  to be gained by purchasing a new PRO-2005 --  unless,  of
  course, you are a passionate scanner collector.

  The PRO-2005 has  the  right  features  and  performance,
  especially  for  scanning  the  wide 225-400 MHz military
  aircraft band.  Good design should not to  be  taken  for
  granted.   GRE  engineers used the power of the micropro-
  cessor to implement  useful  features  in  the  PRO-2005.
  Similar  processing  horsepower was not used so wisely in
  the Yaesu FRG-9600.

  At about $420, the PRO-2005 provides a  good  alternative
  to those not wishing to spend $1050 for an ICOM R7000.