AOR AR-2700 Wideband Reciever Operating Manual

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Note:  Even when the squelch is fully CLOSED a low level background
noise may still be audible.  This is because the receiver’s audio amplifier
circuit is permanently operational in order to provide fast search/scan rates and
an efficient squelch opening characteristic.  This phenomenon is common with
other hand-held receivers on the market today.
5-5  VOL - volume control
The volume control is located on the top face of the cabinet.  This
control is used to set the required audio output from the receiver.
When rotated fully clockwise the volume is at maximum, when rotated
fully anti-clockwise the volume is reduced to minimum.
Front panel
5-6  Liquid Crystal Display (LCD)
The AR2700 uses a high contrast Liquid
Crystal Display.  Due to its mechanical
construction the LCD is best viewed from
directly in front of the receiver, a fairly
wide viewing angle is still maintained.
The LCD is custom manufactured and has
legends for mode, channel step, bank
number, frequency etc.
A full test pattern may be displayed by holding the [1] key while switching the
receiver On until the set fully powers up.  Not all legends are used by the
AR2700.  To remove the test pattern, briefly press the [PWR] key again.
Attractive green rear illumination of the LCD (and keypad) is switchable for use
in locations of low level lighting.
The LCD will provide frequency readout to tens of Hertz (the last digit on the
right is used when using 6.25 kHz steps otherwise it will always read “0”).
The lower left corner of the LCD displays a legend “BUSY” to indicate that the
squelch is open.  To the right is the signal strength presented as a bar graph.
The stronger the signal then the larger the graph, if there is no signal present
this area of LCD will be blank.  It is quite common for a few of the signal
meter segments to appear due to background band noise even when no
signal is present.
5-7  Keypad
The front keypad comprises of twenty press keys laid in a grid four horizontal
and five vertical.  The keys are multi-function and are used to input frequency 
						

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and other operational data in conjunction with the left side panel [2ndF]
function key and top panel [DIAL].
If a key is not pressed within about 30 seconds during data entry, the entry will
be aborted and the receiver will return to the previous display.
Attractive green rear illumination of the front keypad and LCD is switchable for
use in locations of low level lighting.
The basic operational description of each key is as follows:
[PWR] - power On/Off key
When the [PWR] key is pressed and held for more than 1.5 seconds the
microprocessor will switch the receiver On.  The requirement of PRESS
AND HOLD prevents accidental switch On and Off. 
						

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When correctly activated and BEEP enabled, a high pitch bleep will confirm
operation.
To switch the receiver Off simply press and hold the key again for more than
1.5 seconds.  If the BEEP is enabled and you press the key for too short a
period, a low pitch beep advises of the error.
The [PWR] switch is not of a common volume control combined arrangement
as a SLEEP timer can also switch the receiver Off when programmed and
activated.  Resetting the microprocessor from the external reset switch will also
cause the receiver to power On.
The K.LOCK (key lock) switch located on the left side panel prevents
accidental switch On and Off of the receiver.  This is an extremely useful
feature when carrying the set in a coat pocket or bag.
Note: It is quite normal for a click to be heard as the receiver is powered On
and often the lamp will momentarily illuminate.  A low level hiss may also be
heard from the speaker when in quiet surroundings, this is because the audio
amplifier is permanently powered in order to provide fast scan & search rates
and to facilitate a good squelch characteristic.  The set may switch On when
changing batteries or when connecting external power to the receiver, this is
normal and you should be aware of and check for this condition.
[SRCH] [S.PROG] - search & search program key
When the [SRCH] key is first pressed the receiver initiates a the
search process for one of the programmed search banks.  The bank
currently being searched is indicated by the legends “BANK 1” for example in
the top left hand corner of the LCD and the word “SEARCH” in the centre of
the top row of the LCD.
If no data is stored in the program search banks, the set will not be able to
search.
When [SRCH] is pressed a second time during search, the SEARCH process
is cancelled and the current search frequency is transferred to the VFO
returning the receiver to MANUAL mode where the frequency may be
monitored or used as the starting point for tuning.  As the search process is
terminated you may also decide to write the frequency into a memory channel
or resume searching again.  To return from SEARCH to MANUAL mode and
receive the original frequency without transferring the search frequency press
[MANU].
The key sequence [2ndF] [SRCH] (short press of the [SRCH] key) initiates the
process for programming the search banks to your own specification of
frequency range, step size, attenuator and mode... this is referred to as
PROGRAM SEARCH input.
The key sequence [2ndF] [SRCH] (long press of the [SRCH] key for more than
1.5 seconds) initiates the process for linking search banks together. 
						

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[SCAN] [BANK] - scan / memory recall / search bank preview key
When the [SCAN] key is pressed briefly, the receiver enters MEMORY
RECALL mode, the display legend “BANK” appears on the top left of
LCD along with bank and channel number.  The receiver monitors whatever
frequency is displayed on the LCD.  The numeric keypad may be used to recall
a specific memory channel between 000 - 049, 100 - 149, 200 - 249 etc up to
949.  Alternatively the  UP / DOWN keys may be used to sequence through
MEMORY CHANNELS WHICH CONTAIN DATA ONLY, the [DIAL] may also
be rotated with the same effect.
When [SCAN] is pressed a second time (this means pressing while “BANK” is
displayed), the receiver returns to MANUAL mode and the memory data is
transferred to VFO where it may be monitored or used as the starting point to
tune from.  To return to MANUAL mode without transferring the memory
contents press [MANU] instead.
When [SCAN] is pressed a second time (this means pressing while “BANK” is
displayed) and held for more than 1.5 seconds, the receiver enters scan
mode and starts looking for active frequencies in the currently selected
memory bank(s).  Alternatively the [UP] or [DOWN] keys may be pressed and
held for more than 1.5 seconds at this point to initiate the scan process.
If a busy channel is located, the scan process will wait until the channel clears
before continuing.  You may force the scan process to continue or reverse in
direction by using the UP / DOWN keys or  [DIAL].
The sequence [2ndF] [SCAN] (in other words the selection of [BANK]) has
three different effects depending upon the operational mode of the receiver at
the time the sequence is keyed.
Manual mode
If the sequence [2ndF] [BANK] is keyed in manual mode, the legend “BANK”
is displayed on the top left corner of the LCD along with a bank number.  The
bank number represents the current MEMORY BANK where you wish data to
be stored during memory write, the receiver automatically increments to the
first available empty location in the bank selected.  Use the UP/ DOWN keys or
[DIAL] to select the memory bank starting point for memory write, to accept
the selection press [ENT].
This sequence is not essential as the bank may always be specified during
memory write, however this facility may increase the speed of data entry at
critical times when there is plenty of interesting activity to save in the memory
banks.
Search mode
If the sequence [2ndF] [BANK] is keyed in search mode, the legend “BANK” is
displayed on the top left corner of the LCD along with a bank number.  The
upper and lower limits of program search are displayed along with the legends 
						

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“HI” and “Lo”.  Use the UP / DOWN keys or [DIAL] to select the desired
program search bank, pressing  [ENT] or [CLR] will cause the receiver to
search the selected program search bank.
Scan mode
If the sequence [2ndF] [BANK] is keyed in scan mode, the legends “BANK”
and “CH” are displayed in the top left corner of the LCD.  The receiver will
pause on the currently displayed channel for about 30 seconds before
resuming the scan process again.  The UP / DOWN keys, [ENT] key or [DIAL]
may be used to force the scan process to resume.
The sequence [2ndF] [SCAN] with the [SCAN] key held for more than 1.5
seconds, causes the receiver to enter the SCAN BANK LINK menu regardless
of whether the receiver is in SEARCH, SCAN or MANUAL operational modes.
[MANU] - manual mode
The AR2700 receiver has a manual operational mode often referred to
as VFO MODE.  The term VFO historically means “Variable Frequency
Oscillator” and today refers to a tunable data store which contains frequency,
mode, channel step, and attenuator information.
Pressing the [MANU] key places the receiver into a known operational
condition ready for data entry.  The display legend “MANUAL” appears toward
the top right of the LCD.  If you are ever unsure what operational mode the
receiver is in, press the [MANU] key.
Manual mode is used for frequency entry, change of mode, general listening
and memory write (data entry - into memory channels and program search
banks).
The key sequence [2ndF] [MANU] (with the [MANU] key held for more than
1.5 seconds) places the receiver into MANUAL SEARCH MODE with the
legend “SEARCH MANUAL” appearing on the top line of the LCD.  The
receiver will search upward or downward from the currently displayed
frequency in whatever mode and channel step selected.  The UP / DOWN keys
or [DIAL] may be used to reverse the direction of manual search.
The receiver will stop on active channels and the UP / DOWN keys or [DIAL]
may be used to force the process to continue passed the busy frequency.  To
cancel manual search and monitor the currently displayed frequency press the
[MANU] key.  (Holding the UP or DOWN keys for more than 1.5 seconds also
places the receiver into manual search mode.
[UP] / MHz / SER - key
The [UP] key is used as a DECIMAL —> • 
						

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For example 133.7 MHz  [1] [3] [3] [MHz] [7] [ENT]  there is no need to add
trailing zeros.  Frequencies below 1 MHz may be preceded by [0] [MHz]
frequency  then [ENT].
The [UP] key may be used to force the receiver to continue search / scan from
a busy channel and to reverse the direction of search / scan should the
receiver be tracking downward.  The key will also act as an upward tuning
control just like DIAL.
The key is also used to select menu options under certain circumstances.
The key may be used to place the receiver in manual search mode by pressing
and holding the [UP] key for more than 1.5 seconds while in manual mode.
The key sequence [2ndF] [UP] places the receiver in ready condition to
CLONE data to another AR2700 connected to an optional CU8232 via the
optional IF-ADP.  This facility enables an exact data copy of one receiver to be
made with another possibly belonging to a friend etc.  The display “COPy
SEnd” and a flashing legend “SERIAL” indicates operation.
Use the UP / DOWN keys or [DIAL] to toggle between SEND and RECEIVE
modes, press [ENT] to accept the selection, always select the receive unit first.
The first segment of the signal bar graph will appear to confirm operation,
as the data transfer progresses so the bar graph will grow to indicate that
the process is functioning correctly.  It will take a few minutes to transfer
all the data.
The sequence [2ndF] [UP] with the UP key being held for more than 1.5
seconds places the receiver into the menu to select the RS232 parameters for
connection to a computer via the optional IF-ADP and CU8232 adaptor and
interface units.
The [DIAL] is used to select the baud rate between 9600, 4800 and 2400 bps
and the UP / DOWN keys select the addition of LF (line feed).
[DOWN] / kHz / SS - key
The [DOWN] key is used as a kHz key during frequency entry and
provides an alternative method of frequency entry to the MHz (decimal)
key method.
For example, a frequency of 945 kHz may be entered as [0] [MHz] [9] [4] [5]
[ENT] or [9] [4] [5] [kHz] [ENT] the later taking one less key press.
This kHz method of entry makes entry from short wave frequency listings
particularly easy.  A listing of 6045 kHz (6.045 MHz) may be entered as
[6] [0] [4] [5] [kHz] [ENT]
The [DOWN] key may be used to force the receiver to continue search / scan
from a busy channel and to reverse the direction of search / scan should the
receiver be tracking upward.  The key will also act as an downward tuning
control just like DIAL. 
						

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The key is also used to select menu options under certain circumstances.
The key may be used to place the receiver in manual search mode by pressing
and holding the [DOWN] key for more than 1.5 seconds while in manual mode.
The sequence [2ndF] [DOWN] places the receiver into “SS” descramble mode,
refer to the information supplied with the optional printed circuit board, not
available within the UK.
The sequence [2ndF] [DOWN] with the DOWN key being held for more
than 1.5 seconds places the receiver into “SS” descramble 
select mode, refer
to the information supplied with the optional printed circuit board, not available
within the UK.
[1] [ATT]  Numeric 1 / ATTENUATOR key
This key acts as a numeric 1 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 1.
If the sequence [2ndF] [1] is keyed, the attenuator is toggled On/Off.  The
ATTENUATOR is a useful feature to aid with the reduction of interference
caused by the presence of strong signals.
[2] [STEP]  Numeric 2 / STEP key
This key acts as a numeric 2 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 2.
If the sequence [2ndF] [2] is keyed, the tuning STEP size may be selected.
[3] [MODE]  Numeric 3 / MODE key
This key acts as a numeric 3 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 3.
If the sequence [2ndF] [3] is keyed, the receive MODE may be selected.
[4] [REC/PLAY]  Numeric 4 / Record / Play (optional) key
This key acts as a numeric 4 when entering frequencies via the
keypad.
In search, scan and memory modes this key is used to identify bank 4. 
						

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If the sequence [2ndF] [4] is keyed, the legend “PLAY” will be displayed on the
LCD and a previous 20 second digital recording may be replayed (presuming
that the optional record chip has been fitted).  If the optional chip has not been
fitted then white noise will be heard.
The signal meter acts as a “progress meter” to illustrate how much record and
play back time has elapsed.
If the sequence [2ndF] [4] is keyed with the [4] key held for more than 1.5
seconds, the legend “REC” will be displayed on the LCD and the current
displayed frequency will be recorded for 20 seconds (presuming that the
optional record chip has been fitted).
[5] [SLEEP]  Numeric 5 / Sleep key
This key acts as a numeric 5 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 5.
If the sequence [2ndF] [5] is keyed, the sleep timer is enabled.  A clock
legend will be displayed on the lower right of the LCD and the receiver will
automatically switch Off after the programmed sleep time has elapsed.  To
de-activate the sleep timer, key the sequence [2ndF] [5] a second time, the
clock legend will be removed from the LCD.
To program the sleep timer between 1 and 120 minutes in one minute
increments key the sequence [2ndF] [5] with the [5] key held for more than
1.5 seconds. The new value may be keyed through the numeric keypad or the
UP / DOWN keys may be used or the [DIAL].  To accept the new value press
[ENT].
[6] [DELAY]  Numeric 6 / DELAY key
This key acts as a numeric 6 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 6.
If the sequence [2ndF] [6] is keyed, the 
global DELAY (used in search and
scan modes) may be programmed by the operator.  The delay is the time
between the frequency becoming clear (squelch closing) and the automatic
continuation of the search or scan process.  The default is 2.0 seconds and the
accepted range is between 0.0 and 9.9 seconds.
The value may be changed by keying in a two digit number via the numeric
keypad (the decimal is automatically entered by the microprocessor) or the
UP / DOWN keys or [DIAL] may be used to change the value in 0.1 second
increments.  Press [ENT] to accept the new value.
[7] [M.DEL]  Numeric 7 / Memory delete key
This key acts as a numeric 7 when entering frequencies via the keypad. 
						

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In search, scan and memory modes this key is used to identify bank 7.
If the sequence [2ndF] [7] is keyed while in memory recall mode or when
stopped on a channel during scan, the displayed frequency will be deleted
from the memory bank and the set will move on to the next memory channel
containing data (upward or downward depending upon how
programmed).
Memory channels are usually deleted one at a time.  It is possible however to
delete a selected bank or all banks, this will be further described later in the
manual.
[8] [CH.PASS]  Numeric 8 / channel pass key
This key acts as a numeric 8 when entering frequencies via the
keypad.
In search, scan and memory modes this key is used to identify bank 8.
If the sequence [2ndF] [8] is keyed during memory recall mode, the legend
“CH PASS” will appear on the LCD to indicate that the channel has been
LOCKED OUT (passed) so that it will not be automatically scanned but will be
skipped over.
This is useful for temporarily passing busy channels such as amateur band
repeaters or broadcast transmissions.  The locked out channel may still be
recalled and monitored in memory recall mode.
To reinstate the locked out channel repeat the key sequence [2ndF] [8] while
the desired channel is being displayed.  The legend “CH PASS” will be
removed from the LCD.
[9] [PAUSE]  Numeric 9 / Pause key
This key acts as a numeric 9 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 9.
If the sequence [2ndF] [9] is keyed the 
global PAUSE facility will be engaged
and the legend “PAUSE” will be displayed on the LCD.  The pause facility is
used in search and scan modes and causes the receiver to wait for a
programmable period before resuming the search or scan process even if the
transmission continues (when the squelch is still open).  This can be very
useful should unwanted continually active frequencies be encountered or if
analysing activity.
To program the PAUSE time, key the sequence [2ndF] [9] and hold the [9]
key for more than 1.5 seconds.  The pause default is 05 seconds and the
accepted range is between 01 and 99 seconds.  The value may be changed by
keying in a two digit number via the numeric keypad, or the UP / DOWN keys
or [DIAL] may be used to change the value in one second increments.  Press
[ENT] to accept the new value. 
						

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[0] [LAMP]  Numeric 0 / Lamp key
This key acts as a numeric 0 when entering frequencies via the keypad.
In search, scan and memory modes this key is used to identify bank 0.
If the sequence [2ndF] [0] is keyed, the LAMP will be switched on for a period
of about five seconds.  If you are using the keypad, the five second timer starts
from the last key press so that you are not inconvenienced in areas of low level
lighting by the lamp switching Off while you are keying in data.
It is possible to switch the lamp On permanently using the key sequence
[2ndF] [0] with the [0] key help for more than 1.5 seconds.  This is useful
for base station or mobile operation but uses more power so will reduce the
operational time if running from batteries.  To switch the lamp Off (if it has
been switched permanently On) use the sequence [2ndF] [0].
[PASS] [BEEP] Frequency pass / beep key
The [PASS] key is used during search to skip unwanted frequencies,
these may be permanently active control channel transmissions,
broadcast stations, spurii etc.  Up to 50 frequencies may be passed in
this way and are held in a list numbered from 00 to 49.
When the search process stops on an active channel press [PASS].  The
frequency will automatically be assigned to a pass channel and the set will
move on to the next frequency in search mode.  If the set fails to respond to
the [PASS] key then all 50 PASS channels have probably been used up and
you will need to delete some in order to make more channels available.
To review the pass list press and hold the [PASS] key for more than 1.5
seconds while in MANUAL or SEARCH mode.  The legends “CH” and
“PASS” will be flashing on the LCD to indicate that the pass list has been
accessed and the first frequency in the list will be displayed along with its pass
channel number “00”.
The list may be reviewed using the UP / DOWN keys or by using the  [DIAL].
A pass frequency may be deleted by first displaying the selected frequency in
the pass list then keying [0] [ENT].  The frequency will disappear and the list
will “shuffle down” to fill the gap which has been made.  It is also possible to
delete the entire list in one go, this will be described later in the manual.
Frequencies may be manually added to the pass list by first displaying the
chosen pass channel then keying in a frequency followed by [ENT], the
pass list will increment to the next channel.  To escape from the pass list
press [CLR].
The key sequence [2ndF] [PASS] toggles On and Off the keypad “beep” and
“boop” confirmation tones.  The beep tones can speed up entry of data via the
keypad as you need to look at the LCD less often.  If you have the keylock On
and attempt to access the keypad, the beep low tone “boop” draws attention to
the fact that the keypad is locked.