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
> 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
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 -
THE RADIO SHACK PRO-2006 PROGRAMMABLE SCANNER
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
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.
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.
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
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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