AOR AR2700 User manual

AR2700 operating manual
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(1) Introduction & accessories
Thank you for purchasing the new AOR AR2700 wide band receiver.
This operating manual is divided into many sections and presented in a logical
order assuming that it will be read section by section following the examples.
However, if you are familiar with the operations of modern multi-function
receivers you may proceed directly to section 6. Many phrases are
repeated through the manual, while this may make the text a little repetitious, it
should provide clear instructions if you refer directly to a specific section.
Every effort has been made to make this manual correct and up to date. Due
to continuous development of the receiver and by error or omissions,
anomalies may be found and this is acknowledged.
Most apparent faults are usually due to accidental misoperation of the receiver,
carefully read all of the manual before deciding to return the receiver for repair.
Although carefully designed, this receiver (like all receivers) suffers from a
degree of internal noises known as spurii. They are a product of the receiver’s
circuitry and do not represent a fault.
This manual is protected by copyright AOR LTD 1995. No information
contained in this manual may be copied or transferred by any means without
the prior written consent of AOR LTD. AOR and the [AOR] logo are trade
marks of AOR, LTD. All other trade marks and names acknowledged. E&OE.
© 1995 AOR LTD.
Operating manual Conventions and special notes
Where text appears in [SQUARE BRACKETS] the keys are to be pressed
exactly as shown.
For example: [1] [4] [5] [ENT]
Means press the 1key followed by the 4key followed by the 5key
followed by the ENTER key.
The arrow keys to the lower left of the keypad are referred to as UP / DOWN or
[UP] [DOWN] keys.
Words contained in speech marks “BANK” refer to indications displayed on the
Liquid Crystal Display.
Where memory banks etc are empty the indication “- - -” is often displayed.
[2ndF] function key: The function key [2ndF] provides access to additional
facilities via the numeric keypad. The function key should be momentarily
pressed only (so that the legend “2ndF” appears in the top left corner of the
LCD) before another numeric key is pressed... do not hold the function key
in while pressing other keys.

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[PWR] power switch: The power switch is not of the traditional “click”
operation but microprocessor controlled, this is to facilitate the sleep timer.
To switch the receiver On, press and hold the [PWR] key for more than
1.5 seconds. Similarly to switch the receiver Off, press and hold the [PWR]
key for more than 1.5 seconds.
Full microprocessor reset: Later in this manual reference is made to FULL
microprocessor reset. The AR2700 takes about 30 seconds to recover
following a FULL reset as all memory and search data has to be deleted...
be patient as 30 seconds feels like a very long time when you are waiting.
Remember also, when there is no memory or search data, the AR2700 will not
scan or search until you have input new data.
1-1 Accessories supplied
4 x AA internal high capacity rechargeable NiCad batteries
Mains charger
DC power lead with cigar lighter plug
Telescopic whip aerial
Belt clip with two screws
Hand strap
Operating manual
(2) Table of contents
1 Introduction and accessories ............................. 1
1-1 Accessories supplied ............................................ 2
2 Table of contents ................................................ 2
3 Major features ..................................................... 4
4 Precautions ......................................................... 6
4-1 Location ............................................................... 6
4-2 Looking after your receiver .................................... 6
4-3 Power requirements .............................................. 6
4-4 NiCads and charging ............................................ 7
4-5 Aerial (antenna) connection .................................. 8
5 Controls and functions ....................................... 9
TOP PANEL ......................................................... 9
5-1 Aerial (antenna) input ........................................... 10
5-2 Earphone connection / speaker connection ........... 10
5-3 [DIAL] - tuning control / selector ............................ 10
5-4 Squelch control ..................................................... 10
5-5 Volume control ...................................................... 11
FRONT PANEL .................................................... 11
5-6 Liquid Crystal Display LCD ................................... 11
5-7 Keypad (extensive information) ............................. 11
5-8 Internal loudspeaker ............................................. 22
LEFT HAND SIDE ................................................ 22
5-9 [2ndF] function key ............................................... 22
5-10 [MONI] monitor key .............................................. 23
5-11 [K.LOCK] keypad lock key .................................... 23

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5-12 [RESET] microprocessor reset switch .................... 23
RIGHT HAND SIDE ............................................... 24
5-13 DC 12V - charging and DC input socket ................. 24
REAR CABINET .................................................... 24
5-14 RS232 REMOTE connector ....................................25
5-15 Battery compartment ..............................................25
6 Basic manual operation of the receiver ............. 26
6-1 Before starting ...................................................... 26
6-2 Switching On ......................................................... 26
6-3 Entering frequencies (using the keypad) ................ 27
6-4 Correcting frequency input ..................................... 28
6-5 Changing frequency - UP / DOWN keys & [DIAL] ... 29
6-6 Changing frequency step (PROGRAM) .................. 29
6-7 Changing receive mode (PROGRAM) ................... 31
6-8 Attenuator ............................................................. 32
7 Memory banks & channels ................................. 33
7-1 Storing receive data into memory .......................... 33
7-2 Automatic memory incrementation ........................ 34
7-3 Memory recall ....................................................... 35
7-4 Transfer of memory channels to VFO .................... 36
7-5 Memory over-write ................................................. 36
7-6 Deleting memory channels and banks .................... 37
8 Priority operation ................................................. 38
8-1 Entering data into the priority channel .................... 38
8-2 Activating & deactivating priority ............................ 39
8-3 Programming priority sampling interval ................. 39
9 SCAN - scanning memory channels & banks ..... 40
9-1 Starting to scan, considerations ............................. 40
9-2 Scanning a memory bank ...................................... 40
9-3 Memory transfer to VFO ........................................ 41
9-4 Scanning a single memory bank to scan ................ 42
9-5 Memory bank linking .............................................. 42
9-6 Scanning a memory bank which is not linked ......... 43
9-7 Scan channel PASS ...............................................43
9-8 Memory scan channel pass while scanning ............ 43
9-9 Memory channel pass - review ............................... 43
10 Delay and Pause facilities - scan & search ......... 44
10-1 Delay time ............................................................. 44
10-2 Pause time .............................................................45
11 SEARCH ................................................................46
11-1 Manual search ....................................................... 46
11-2 Frequency pass in search mode ...............................48
11-3 Program search banks ........................................... 49
11-4 Reviewing program search parameters ...................50
11-5 Programming and reprogramming search banks .... 51
11-6 Program search bank linking ..................................53
11-7 Searching a search bank which is not linked ...........54
12 Sleep timer - automatic power off ....................... 54
12-1 Enabling sleep time ................................................. 55
12-2 Defining the sleep time period ................................ 55
13 Optional VOICE recording facility ....................... 55
13-1 Initialising the voice record option ...........................55
13-2 Recording ............................................................. 56

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13-3 Record - Play back ............................................... 56
14 Remote control using a computer (RS232) ....... 56
14-1 Setting RS232 parameters .................................... 57
15 Clone (copy) data between two AR2700 .............. 57
15-1 Transferring data by clone .................................... 57
16 Trouble shooting ................................................. 58
16-1 Microprocessor reset ............................................. 58
16-2 Other possible operating problems ........................ 59
16-3 Other LCD indications & error messages ............... 60
16-4 Special functions ................................................... 61
17 Optional accessories ........................................... 62
18 Specification ........................................................ 63
(3) Major features
General
The AR2700 is a new generation of receiver combining a wide frequency
coverage with advanced features and facilities.
Internal construction is of a high quality modular surface mount design. This
ensures the highest levels of performance and reliability.
Frequency coverage and modes
The AR2700 boasts a wide frequency coverage of 500kHz to 1300MHz without
gaps in the range (actual acceptable frequency input from 100kHz). Step size
is programmable: AM/NFM 5kHz, 6.25kHz, 9kHz, 10kHz, 12.5kHz, 20kHz,
25kHz, 30kHz, 50kHz, 100kHz and WFM: 50kHz & 100kHz. Modes of
reception are: AM, NFM and WFM and may be selected on any frequency
within the receiver’s range.
Auto-Mode tuning
Comprehensive band plan information specific to the target market area has
been programmed into the AR2700 receiver. This inclusion will greatly simplify
frequency entry and search programming, the receiver will “automatically”
select the appropriate mode and channel step. Of course, should you wish
then both the mode and channel step may be manually changed when
required.
Wide variety of search & scan facilities
Great flexibility is offered by the microprocessor. Search & scan may be
selected using various parameters such as PROGRAM SEARCH, MANUAL
SEARCH, BANK LINK, DELAY, PAUSE, PASS etc. plus PRIORITY.

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Memories and search banks
A total of 500 memory channels are provided which are divided into 10 banks,
each having 50 channels. The AR2700 will search and scan at a very
respectable (and fast) maximum speed of approximately 30 increments per
second.
In addition there are 10 programmable search banks, all of which may be
programmed by the operator for different start / end frequencies, mode and
channel step.
The data contents of memory and search banks are held in an EEPROM so
that no backup battery or capacitor is required for memory retention.
Copy (CLONE) between two AR2700 receivers
The stored memory and search data may be transferred from one set to
another using an optional adaptor and interface (IF-ADP & CU8232).
Full computer control
The computer control port may be connected via an optional adaptor and
interface (IF-ADP & CU8232) to a computer for remote control of the receiver
(control software will be required).
On screen battery indication
The AR27000 permanently displays the battery level status when switched On,
this is achieved by a special indication on the LCD.
Sleep timer
The AR27000 has an auto power off sleep timer programmable between 1 and
120 minutes. A special indication on the LCD shows when the facility has
been activated.
Optional VOICE recording
An optional VOICE recoding chip (RU2700) may be internally fitted to permit
20 second digital recording and play back of transmissions.
Other facilities
The AR2700 is truly full featured, among other facilities are keypad beep
On/Off, plus keypad lock and microprocessor reset.

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(4) Precautions
4-1 Location
Do not use or leave the receiver in direct sunlight (especially the LCD). It is
best to avoid locations where excessive heat, humidity, dust and vibration are
expected. Always treat the receiver with care.
Take care to avoid spillage or leakage of liquids into the receiver and AC
charger. Special care should be taken to avoid liquid entering via the power
jack and earphone sockets. Always remove batteries if the receiver is not
going to be used for a while.
Avoid static discharge from discones or long wire aerials, earth to a central
heating radiator or similar earthing point in order to discharge the wire aerial
before connection to the receiver. Always disconnect and earth any external
aerial system if an electrical storm is expected.
Avoid connecting / disconnecting the power connection or batteries with the set
switched On. Avoid a rapid switch On/Off sequence. If switched Off, leave at
least two seconds before switching On again. Ensure the mains plug
connections are tight and other DC connections (such as cigar lighter plugs)
secure.
Avoid strong RF fields from nearby transmitters. If in doubt, disconnect the
AR2700 from the aerial and switch the set Off.
4-2 Looking after your receiver
Always keep the receiver free from dust and water. Use a soft dry cloth to
gently wipe the set clean. Never use chemicals such as benzine or thinners
which will damage certain parts.
4-3 Power requirements
The AR2700 is designed for operation from internal NiCad batteries, internal
dry batteries or an external DC supply of 11 - 16V DC at approximately 300mA
minimum.
Always use the mains charger provided or a regulated DC power supply of
13.8V @ 300mA or more using the provided DC connecting lead. NEVER
CONNECT THE AR2700 DIRECTLY TO THE MAINS SUPPLY. Always
switch the receiver Off when connecting or disconnecting the receiver.
Note: The DC input socket uses a standard dual concentric 1.3mm connector.
The connector is CENTRE POSITIVE (which is the RED terminal of most DC
power supplies). The outer connector is NEGATIVE - ground.
Should you be using the AR2700 at home with an external aerial, a separate
earth connection may be made between the outer earth connector of the BNC

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plug and water pipe, central heating system radiator or external earth rod. If
fitting a separate external earth rod, consider the implications carefully if your
mains supply uses a Protective Multiple Earth (PME) system. If in doubt
consult an experienced electrician. Never earth to a gas pipe!
Always disconnect the charger from the AC mains supply when not in use.
If using dry batteries (Alkaline or Manganese), always remove the batteries
when exhausted or if the AR2700 is not going to be used for a while. This will
avoid leakage which could seriously damage the receiver.
There is a special on screen battery indicator with three segments
indicating state of charge / drain. The indicator is useful in
providing a short period of warning of low battery power.
Three segments indicates that there is plenty of charge in the
batteries, two segments indicate that the batteries are beginning to
loose their charge and one segment indicates that the batteries are
about to expire.
Background noise may still be heard from the loudspeaker even
though the batteries are exhausted, usually the Liquid Crystal Display or
receiver fails to operate in this condition.
Access to the battery compartment is via a
removable sub-panel on the rear
of the unit using a downward motion. Always
switch the receiver Off when inserting or removing
batteries. If fitting new batteries always select a
quality brand, 4 x AA size 1.2 or 1.5V cells are
required.
When replacing batteries the receiver may
automatically switch On, this is quite normal.
4-4 NiCads and charging
Before operating, charge the internal NiCad
batteries using the supplied charger for
approximately 16 hours.
NiCads are prone to “memory effect”, as a result
they may have to be cycled (fully charged then
used until flat) 3 or 4 times before they provide a
truly full period of operation. Once charged, you
should never again leave the NiCads in a flat condition. Although you may
charge the NiCads in order to “top up” their capacity if you have only used the
set for an hour or two, the NiCads should be cycled at least once per month to
ensure continued long term reliability.

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Important!
Do not overcharge the NiCad pack, 16 hours is
sufficient from flat. In severe cases of overcharging
high temperatures may be generated, this can result
in damage to the NiCads and to the receiver. If this
point is ignored, there is a small but potential danger
of personal injury due to explosion. Never short
circuit NiCad batteries, the effect is similar to
overcharging but happens very quickly. Never
attempt to charge dry batteries.
4-5 Aerial (antenna) connection summary
The aerial input is via a high quality BNC 50 OHM
socket. The standard supplied telescopic whip
should provide good result across most of the
receiver’s frequency coverage with the exception of short wave & medium/long
wave.
The BNC socket should also permit straight forward connection to almost any
type of receive aerial setup.
It is not possible to further increase sensitivity on medium wave, firstly due to
the up-conversion receive circuit employed (which is required for high quality
VHF-UHF reception) and secondly due to the potential noise from the
microprocessor (being a compact hand-held design).
Aerial attenuator
An aerial attenuator system allows selection of 0dB or 10dB. This is especially
useful in reducing the potential for breakthrough when using external aerial
systems.
Do remember, if considering the use of an external aerial, there will be a
greater chance of signal overload and breakthrough. While this will not
damage the receiver in average use, it may degrade the receive performance
due to the effects of “signal mixing”. Liberal use of the attenuator may be
required.
VHF - UHF discone aerials
Ideally, separate aerials should be employed for each frequency or band of
interest. Of course, except for government listening stations this is totally
impractical. For this reason most people choose an externally mounted
discone aerial such as the AOR DA3000 aerial. The DA3000 has a usable
frequency coverage of 25 to 2000 MHz.

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Shortwave long wire aerials
For the shortwave bands a different type of aerial will be required. The most
common form is the random long wire connected to the centre terminal of the
BNC plug or wrapped around the retracted telescopic whip aerial.
Aerial Tuning Units (ATU)
An ATU can improve the selectivity of any shortwave receiver when connected
to long wire aerials. This valuable extra selectivity is achieved by the ATU
rejecting out of band signals enabling the receiver to “single out” one band of
frequencies while rejecting potentially strong unwanted transmissions.
Active desktop loop aerials
Usually designed for the shortwave bands (such as the AOR LA320). Loop
aerials have the advantage of small size when compared to long wire aerials
and being within easy reach of the operator they may be rotated to provide
directivity. The circuitry offers a small level of gain with the advantage of
selectivity similar to an ATU.
(5) Controls and functions
The AR2700 receiver is housed in an attractive and modern looking grey
plastic cabinet. Controls for operation are located on the top, front and left
hand side of the cabinet.
Top Panel

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5-1 Aerial (antenna) input
The aerial input is via a high quality BNC 50 OHM socket. The standard
supplied telescopic whip should be connected to this point and provide good
result across most of the receiver’s frequency coverage.
5-2 EAR - Earphone / speaker connection
This 3.5mm mono socket permits connection to an external earphone, headset
or speaker of 8 OHM impedance or greater. When this earphone socket is
used, the internal speaker will be automatically disconnected.
5-3 DIAL - tuning control / selector
The DIAL control is prominently located on the top of the cabinet for
ease of use. This control changes the received frequency up and down
in whatever step increment is selected and operates as a “selector”
when entering certain data though menus. This type of rotary control is
often referred to as the “VFO”.
Being a mechanical device, it is not uncommon for operations to be
occasionally missed and this does not constitute a fault (unless excessive).
5-4 SQ - squelch control
The squelch control is used to eliminate unwanted background noise
when monitoring a normally inactive frequency and is used by the
AR2700 microprocessor to determine when a channel is “active”
(busy). The receiver cannot scan or search when the background noise is
present.
The squelch control requires careful setting to achieve optimum operating
performance. Rotate the control clockwise until the background noise just
disappears (threshold), this is the most sensitive setting of the control. In
practice the control is usually rotated a little further clockwise beyond the
threshold point to prevent the receiver from stopping on noise or very weak and
unreadable signals.
If the control is rotated too far clockwise then weaker signals will be totally lost
and only local strong signals will be heard.
When the squelch control is rotated anti-clockwise so that background noise is
audible, the squelch is referred to as being “OPEN”. In a similar manner, when
the squelch control is rotated clockwise so that the background noise is muted,
the squelch is referred to as being “CLOSED”.
The squelch is not usually used when listening to short wave transmissions
due to the relatively high short wave background noise levels nor in WFM
mode. The usual setting for the control when listening to short wave or WFM
is fully anti-clockwise (squelch open).