431 lines
16 KiB
Plaintext
431 lines
16 KiB
Plaintext
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THE RADIO SHACK PRO-2005 PROGRAMMABLE SCANNER
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by Bob Parnass, AJ9S
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Manufactured in Japan by General Research Electronics,
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the Radio Shack PRO-2005 is a 400 channel, wide coverage
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scanner radio, incorporating NBFM, WBFM, and AM modes.
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It is the successor to the PRO-2004, the super scanner
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which put Radio Shack out in front of its competition in
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the base station scanner market.
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The 2005 is basically a 400 channel PRO-2004, built using
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surface mount components, and housed in a smaller pack-
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age.
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Frequency Coverage
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Radio Shack's last minute decision to remove cellular
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telephone frequency coverage from the PRO-2004 caused a 7
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week delay in its introduction. The PRO-2005 appeared in
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the stores promptly on the heels of the 2004 closeout
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sale. Both the PRO-2004 and PRO-2005 cover 25-520 and
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760-1300 MHz, except for 2 gaps in the cellular telephone
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bands. The two gaps in the 800 MHz range can be restored
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in either scanner by clipping a diode.
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A matrix of diodes, attached to the microprocessor's
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input port, is often used to configure radios for sale in
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different markets. The diode matrix on new the PRO-2005
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is located on the vertical circuit board just behind the
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front panel. There are 2 diodes present, and holes
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drilled for 2 more.
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Lots of Memory
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The PRO-2005 has the usual features that scanner buffs
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have come to expect: individual channel lockouts,
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selectable rescan delay, an external speaker jack, etc.
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But, the 400 channel capacity of the PRO-2005 sets
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another an industry record, just as the 300 channel PRO-
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2004 did! Casual scanner users may scoff at the useful-
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ness of having so many channels, but seasoned monitorists
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can have those channels filled up in no time flat, espe-
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cially with frequencies in the vast 225-400 MHz military
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air band, and other federal government allocations.
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With so many channels to program, one dreads the thought
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of a power failure, which could clear memory in a hurry.
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Not to worry, the PRO-2005 memory is backed up by a
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- 2 -
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conventional 9 volt alkaline battery (not supplied). The
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400 channels are divided into 10 banks of 40 channels
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each, and one can select or deselect any channel bank
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from the scan list. Individual channels can be locked
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out in the customary way, but the PRO-2005 maintains the
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handy feature introduced in the PRO-2004, a LOCKOUT
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REVIEW. Successive depressions of this key step through
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the locked out channels.
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Scanners worth their keep have a priority feature, with
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channel 1 usually designated the priority channel. The
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PRO-2005 is more flexible; any of the 400 channels may be
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designated the priority channel. When the PRIORITY key
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is depressed, that channel will be sampled every 2
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seconds, and the radio will stay there if a signal is
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heard.
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The PRO-2005 has two scan speeds, approximately 8 and 16
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channels/second, although one would probably use the fas-
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ter speed in most instances. This is the same speed as
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the stock PRO-2004, as measured by your reviewer. A
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diode could be added to the PRO-2004 diode matrix to
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speed up the scan and search rates by 25%. The provision
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for extra diodes in the diode matrix makes one hopeful
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that the same speedup trick can be applied to the newer
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PRO-2005.
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When programming a channel, the PRO-2005 firmware sets
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the mode automatically, based on its idea of what mode is
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most prevalent on that frequency. This feature saves
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extra keystrokes, and makes one appreciate the thought
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that went into the design of this radio. The default
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mode can be overridden easily, if need be, like to listen
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to a NBFM satellite in the 225-400 MHz range, which is
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mainly populated with AM signals.
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Searching
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The SEARCH facility found on most programmable scanners
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allows the entry of a pair of frequencies, then by press-
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ing a key, the radio searches frequencies between those
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limits. The PRO-2005 allows for 10 pairs of limits!
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These pairs of limits are stored in their own memory, and
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don't use up any of the conventional 400 memory channels.
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One can set up several search pairs, for instance:
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- 46.610-46.970 MHz: cordless telephones
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- 144-148 MHz: the 2 meter ham band
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- 3 -
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- 30.01-30.56, 32-33, 36-37 MHz: US Govt
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Another unique feature is the MONITOR key, which stops
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the search and stores the frequency in one of ten special
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monitor memories. These memories are separate from the
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400 main memory channels. The search can be restarted
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from where it left off by striking the up or down arrow
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key.
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The user can select the search direction (up or down),
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and step size of 5, 12.5, or 50 kHz, although the PRO-
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2005 is intelligent enough to select a default step size
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based on the frequencies being searched. As on the PRO-
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2004, there is a hidden step size of 30 kHz, but
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apparently this step size was disabled when the cellular
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telephone frequency coverage was removed.
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The selected parameters are displayed on the LCD panel,
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smaller than the panel in the PRO-2004. Search speed is
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switchable between slow and fast, with fast search being
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about 14 increments/second (versus 12 for the
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Uniden/Bearcat 800XLT). For a 12.5 kHz increment, this
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translates to 11.2 MHz/minute (versus 9.6 MHz/minute for
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the 800XLT).
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The DIRECT key allows one to start searching up or down
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from whatever frequency is on the display. Let's say the
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scanner is in MANUAL mode, and set at channel 26, which
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contains 460.100 MHz. Striking the DIRECT then UP-ARROW
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keys starts the PRO-2005 searching upwards from 460.100.
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This is a nice feature.
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The PRO-2005 contains a "window detector" circuit, which
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is called into play during a SEARCH operation. This cir-
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cuit tries to detect when the radio is tuned close to the
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center frequency of a station, and prevents the search
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from halting prematurely, off to the side of the signal.
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The AFC (automatic frequency control) circuit of the
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Bearcat 800XLT often causes a search of 850 MHz signals
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to halt prematurely. Even though the signal sounds on
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frequency, the display reads the wrong frequency. Nei-
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ther the PRO-2004 nor the PRO-2005 have this problem.
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The PRO-2005 includes a SOUND SQUELCH, resembling the VSC
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circuit on the Icom R-7000, which may be used during scan
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or search operations. With the the sound squelch
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enabled, signified by a red lamp above the pushbutton,
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the scanner will skip over unmodulated signals. This is
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handy for skipping over "birdies", or link signals with a
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constant carrier.
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- 4 -
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The manual warns that the sound squelch may be fooled by
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signals with low modulation, and skip over them. The
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PRO-2005 SOUND SQUELCH tries to detect the presence or
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absence of modulation (not human speech), so unfor-
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tunately, it thinks that noisy dead carriers, digital
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data signals, and paging tones are worth monitoring and
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will stop the scanner to listen to them.
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Taping Facility
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A tape recorder can be connected to the TAPE phono jack
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on the rear panel, which provides 600 mV of audio at a
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10,000 ohm impedance. An audio filtering circuit rolls
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off the high frequency components before they reach the
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TAPE jack, which makes it impossible to use it for pick-
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ing off FM subcarrier signals. In addition to a rear
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mounted external speaker jack, there is a miniature head-
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phone jack on the front of the scanner.
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The PRO-2005 lacks a COR (carrier operated relay) output,
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like ICOM R7000 and older Bearcat 300 have, which would
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be useful for actuating a tape recorder.
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Basic Performance
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To evaluate sensitivity, the PRO-2005 was compared with
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it's father, the PRO-2004. Since a signal generator was
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not used, quantitative measurements could not be made.
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Instead, an Antenna Specialists AV-801 antenna was
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switched between radios, signals from stations were com-
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pared by ear, and the results tabulated.
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Simply put, the PRO-2005 proved moderately more sensitive
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than the PRO-2004 on most bands tested, and just slightly
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more sensitive on a few bands. The cost one pays for the
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2005's increased sensitivity is having to put up with
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hearing 800 MHz trunked systems and cellular telephone
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conversations while searching the 118 - 132 MHz commer-
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cial aircraft band. The 800 MHz interference was heard
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only on the 2005, not the 2004. Other than that, inter-
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modulation interference from paging affected both
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scanners to the same degree, and on the same frequencies.
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Although both the 2004 and 2005 can suffer the effects of
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intermod, they are much more immune than the overly sen-
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sitive, image laden Bearcat 800XLT. The PRO-2005 has a
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10 dB attenuator, operable by a slide switch on the rear.
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- 5 -
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The up conversion design of both the ICOM R-7000 and
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Radio Shack PRO-2005 allows use of a very high IF (inter-
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mediate frequency), which helps avoid image problems.
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The PRO-2004 owner's manual contains a frequency alloca-
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tion chart and a section on images. This section appears
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in the manuals for other Radio Shack models, and was
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thoughtlessly thrown into the 2005 manual. It babbles on
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about images being 21.4 MHz away from the real frequency
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-- true for simpler models, but not so for the PRO-2005.
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The audio output quality is good, although the top
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mounted speaker directs the sound at the ceiling, but
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adding an external speaker would allow the sound to be
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directed at the user.
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Unfortunately, the audio level of AM signals is somewhat
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below that of NBFM signals, requiring a different setting
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of the volume control. When scanning both AM and NBFM
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modes, one has to find a compromise position of the
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volume control.
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The PRO-2005 squelch control has a wee bit too much hys-
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teresis, a trait inherited from its ancestors. It's like
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having too much play in a car's steering wheel, or back-
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lash in a gear set. This hysteresis forces one to keep
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the squelch at a tighter setting, missing weaker signals
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when scanning or searching. It's not as sloppy as in the
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early PRO-2004s. I've successfully eliminated this prob-
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lem completely by replacing a single resistor on the
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800XLT, as well as the PRO-2002, PRO-2003, PRO-2004 and
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PRO-24 scanners.
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Mechanical Construction
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The PRO-2005 is lighter than the 2004. It is enclosed in
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a gray plastic cabinet, with a plastic front panel. If
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one is going to pay $420, one deserves to own some metal,
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but several stages are internally shielded in their own
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metal compartments. The entirely plastic cabinet of the
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older PRO2003 allowed wideband noise to radiate out of
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the scanner and into nearby shortwave receivers.
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The PRO-2005 vertical front panel is an advancement over
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the sloping panel of the 2004. Now you can stack the
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scanner on top of other equipment and see the controls
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without standing up. If sitting directly on a table, two
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hinged plastic feet, padded with rubber bumpers, can fold
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out from under the front of the radio to tilt it at a
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good viewing angle.
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- 6 -
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There is a single BNC antenna connector on the rear of
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the PRO-2005, and a single telescoping antenna is sup-
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plied.
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Internal construction is excellent, and the internal
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shielding is commendable. Interstage shielding is very
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important in a wide band receiver, to prevent it from
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"hearing itself", an undesirable phenomena which results
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in birdies. The PRO-2005 owner's manual lists the birdie
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frequencies. The shielding is much better in the PRO-
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2005 than in the 800XLT, which uses no shielding around
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the 800 MHz converter stage, and probably accounts for
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some of the birdies in the Bearcat.
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Frequencies and other indicators are displayed on a back-
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lit LCD (liquid crystal display) panel, and the level of
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backlighting can be dimmed by a pushbutton switch.
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Vision impaired scanner buffs will appreciate the conven-
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tional raised rubber keyboard in the PRO-2005, which
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replaced the flat membrane keyboard in the PRO-2004.
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Only moderate pressure is required for actuation, and key
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depressions are confirmed by a mild "beep" audio tone.
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The PRO-2005 is the right size to fit under the dashboard
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of intermediate sized cars. Although it can be operated
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on 12 VDC, neither a mobile power cord nor mounting
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bracket are provided. These items were included with
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earlier, pre-PRO-2004 Radio Shack models. The AC power
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cord is not detachable, and would have to be bundled up
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to keep it out of the way in a mobile installation.
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Owner's Manual
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The user manual is outstanding compared with the fold out
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sheet furnished with Uniden scanner.
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A single page frequency allocations chart is included,
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but is not current. There is no schematic. Thankfully,
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detailed service manuals for Radio Shack scanners are
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usually available for $7.50 or $10.00.
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The PRO-2005 is warranted for 1 year, which is reassur-
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ing.
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What's Missing?
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So with all these neat features, what's missing from the
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PRO-2005? A "search and store" mode, like that on the
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- 7 -
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ICOM R7000 and older Bearcat 250 would have been nice. A
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lighted keyboard and a signal strength meter would also
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be welcome, as would a mobile mounting bracket and SCA
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output jack.
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Summary
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If all one wants is a scanner to monitor local police and
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fire, there are certainly cheaper and simpler models than
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the PRO-2005. This scanner is for those who enjoy
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actively exploring voice communications in the VHF/UHF
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spectrum. If you already own a PRO-2004 and have added
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the diode to expand it to 400 channels, there is little
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to be gained by purchasing a new PRO-2005 -- unless, of
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course, you are a passionate scanner collector.
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The PRO-2005 has the right features and performance,
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especially for scanning the wide 225-400 MHz military
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aircraft band. Good design should not to be taken for
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granted. GRE engineers used the power of the micropro-
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cessor to implement useful features in the PRO-2005.
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Similar processing horsepower was not used so wisely in
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the Yaesu FRG-9600.
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At about $420, the PRO-2005 provides a good alternative
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to those not wishing to spend $1050 for an ICOM R7000.
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