Post by Hal Hammo » Wed, 26 Jul 1995 04:00:00

A local pawnshop has a Pro-30 they'll "let go" for $75. Is this a good deal?
My main interest is to listen on the air band (118-137 MHz).

What's a good price for a Pro-42?

Hal Hammond

Advance Products Group
Landmark Graphics Corp.
Englewood, Colorado



Post by Bob Parnass, AJ » Thu, 27 Jul 1995 04:00:00

  >A local pawnshop has a Pro-30 they'll "let go" for $75.
  >Is this a good deal?
  >My main interest is to listen on the air band (118-137 MHz).
  >What's a good price for a Pro-42?

The $75 price sounds high for Radio Shack's first programmable
portable scanner.  The PRO-30 was a good scanner in its day, but
that was long ago and it's not attractive by today's standards.
It has only 16 channels, scans slowly, and requires two sizes
of battery.

I've had 7 PRO-30s due to various defects.  Here's  a  brief
report I wrote *several* years ago.

           The Radio Shack PRO-30 Synthesized Scanner

                     Robert S. Parnass, AJ9S

     I recently purchased a Radio Shack  PRO-30  synthesized
     handheld scanner.  Here are some details:

        o Price: $300.

        o Batteries are not included.  The PRO-30 requires 3
          "hearing  aid type" batteries for memory retention
          and 6 AA batteries.

        o Frequency coverage is fixed.  The  manual  states:
          "In  case  you're  wondering,  the tuning range of
          your PRO-30 is permanently stored in the micropro-
          cessor chip.  There's no way it can be extended or
          altered - even by a  skilled  electronics  techni-
          cian.   So  if you try to enter a frequency not in
          the PRO-30's tuning ranges, you'll  get  an  error
          message every time!"

             o 30 - 54 (includes entire 6 meter ham band)

             o 108 - 136 (AM commercial aircraft band)

             o 138 - 174 (includes some military frequencies
               below the 2 meter ham band)

             o 380 - 512 (several military and  "secret"  US
               government frequencies in this range)

        o Semiconductor components: 1 LSI microprocessor,  1
          LSI  PLL  chip,  3  CMOS  chips, 5 other chips, 39
          transistors, and 75 diodes!

        o Scanning rate: Fast = 10 channels/second, Slow = 5

        o IF frequencies: 10.7 MHz and 455 KHz.

                           - 2 -

        o Current drain (not including memory backup cells):
          55  mA  squelched,  100  mA  unsquelched  at  full

        o Priority Sampling: 2 seconds.

        o BNC antenna connector.  A multi band semi-flexible
          antenna is supplied.

        o The case is plastic, with a hinged, spring  loaded
          belt clip on the rear.  The inside of the case has
          been sprayed with some type of  gold  colored  RFI
          shielding material.

        o The keyboard buttons are made  of  a  ***  type
          material,  that  compress slightly when depressed.
          An audio tone is used to confirm key depression.

        o Three pushbutton switches on the top of  the  unit
          duplicate functions on the front mounted keypad:

            a.  Scan

            b.  Manual

            c.  Speed

          This allows the user to manipulate these functions
          while the scanner is worn on the belt.

        o The PRO-30 is made in Japan by GRE, the same  com-
          pany  that  makes Radio Shack's crystal controlled

        o The owner's manual contains a block  diagram,  but
          no  schematic.   I  am told that a service manual,
          with schematic, will be available for  sale.   The
          owner's manual contains a list of "birdies."

     Some early impressions:

        o The scanner works quite well.1


 1. The PRO-30 being reviewed is one of the first available
    in the northern Illinois area.  Early models of complex
    radio equipment from other companies have been plagued
    by several problems.  Examples are the Drake TR-7

                           - 3 -

        o The instruction manual is pretty good, although  a
          schematic should be included.

        o The scanner is bigger than the Bearcat BC-100.  No
          leather  case  is available to protect the PRO-30,
          so the scanner could be "bruised"  in  heavy  ser-

        o The LCD display contains  several  status  indica-
          tors, including a low  battery  warning  message.2
          The  display  is  quite  crisp and clear in bright
          light,  and  when  the  internal  dial  light   is
          activated.   It  is  difficult  to  read under low
          lighting  conditions  and  at  various  angles,  a
          characteristic of LCD technology.

        o Striking a key does not always actuate the desired
          function.   If  a  key  is  struck off center, the
          *** key top compresses  without  actuating  the
          switch  mechanism.  The user is made aware of this
          situation when no audio tone is heard after a  key

          A nice aspect is that the keyboard is  less  prone
          to  damage if it is struck against the corner of a

        o Sensitivity on UHF is at  least  as  good  as  the
          several  crystal controlled portable scanners I've
          aligned, maybe even better!

        o In Search mode, scanning will stop only  when  the
          radio is tuned to a station's center frequency.  A
          "window detector" circuit3  prevents  lock  up  on
          adjacent frequencies.


    transceiver, the Bearcat BC-100 and BC-300 scanners, and
    the Collins KWM-380 transceiver.

 2. The user is also warned of failing batteries by a audio

 3. A similar circuit is found in certain Bearcat
    synthesized models, such as the BC-250.  The original
    patent for this circuit is assigned to General Research
    Electronics (GRE), as are several other scanner patents.

                           - 4 -

        o The internal construction looks decent.  There are
          two printed circuit boards in the radio, connected
          via a multi pin connector rather than messy wiring
          harnesses.  The component designations (e.g. R102,
          C212, etc.) are printed on the  board.   Resistors
          are  1/8  watt  and  mounted  vertically.   Layout
          appears clean, not overcrowded.

        o The priority scan feature works well  and  uses  a
          "reasonable"  algorithm,  like  that  used in most
          Bearcat and Regency scanners.4

        o Audio  output  circuitry  uses  the  LM386   audio
          amplifier  chip, producing about 220 milliwatts of
          audio power out.5 This is a bit on the  weak  side
          if you're using the scanner in a truck, or wearing
          it in a noisy situation without benefit of an ear-
          phone  or  external,  clip-on  lapel speaker.  The
          audio is  crisp  and  clean,  without  synthesizer

        o The 2nd IF, FM detector and squelch  circuitry  is
          implemented  using a Motorola MC3357 IC, now quite
          common in scanners.6


 4. The algorithms used in most Japanese 2 meter ham radio
    transceivers, discussed in a previous article, are not
    very useful to American amateurs.

 5. The LM386 is also used in the PRO-24 crystal controlled
    handheld scanner, reviewed in a previous article.  In
    both models, the speaker element is only rated for 100

 6. The squelch function works quite well and is not plagued
    by the hysteresis problem found in the PRO-24.

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