AOR AR5000 Wideband Reciever Instructions

							AR5000 OPERATING MANUAL          PAGE 71
18-4  AF.SET INT/EXT
The AR5000 may have become confused about the status
of AUDIO INTERNAL / EXTERNAL.  Reaffirm the setup.
1  Press 
  to access the audio setup menu.
A-LPF 3.0 kHz
A-HPF 0.05 kHz
DE.EMP 750
CW.PITCH 0.7 kHz
AUDIO INT  
						

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(19)  Optional accessories
DA3000 VHF-UHF discone aerial
16 element VHF - UHF discone aerial
with usable coverage of 25 MHz to 2000
MHz.  Supplied with cable and
connectors etc.
WA7000 wide band active whip aerial
Compact aerial designed for installation where
space is a problem.  The WA7000 is active on
the lower frequency band 30kHz to
30MHz and passive on the higher
band between 30MHz to 2000MHz.
Supplied with cable and connectors
etc.
MA500 mobile aerial
Compact VHF/UHF loaded whip on a magnetic mount
with coaxial cable.
LA320 loop aerial
Desktop active loop aerial for portable
operation away from a base aerial such
as when while travelling on business or
holiday.  Frequency coverage is 1.6 to
15MHz with optional elements to cover
0.2 to 0.54MHz and 0.54 to 1.6MHz.
ABF125 RF filter
VHF civil airband filter to reduce the chances of
breakthrough especially from powerful VHF band-II
transmitters.
CR5000 tape record cable
Cable and connector suitable for use with motor-controlled
tape recorders.
Collins IF filters
MF500    Optional  500 Hz mechanical
               CW filter
MF2.5     Substitute 2.5 kHz mechanical SSB filter
MF6.0     Substitute 5.5 kHz mechanical AM filter
CT5000 board
CTCSS plug in board for CTCSS search and squelch
operations.
AS5000 aerial switch
Automatic aerial switching unit designed to control four
aerials (automatic and front panel aerial switching with
the AR5000).
DS8000 speech inverter
Speech inverter board (non AOR product).
Not available in all countries.
RS232 command set
Programmers RS232 command listing with information
on configuring Windows terminal. 
A separate serial
connecting lead will also be required to connect to your
computer.
Computer control software
A hands off IBM-PC WINDOWS computer program is
planned to control the AR5000 via the rear panel remote
connector.  
A separate serial connecting lead will also be
required to connect to your computer.
(20)  Aerials (Antennas) and earth systems
The subject of aerial choice and earth can be quite
complex. There are many advantages and disadvantages
to consider before connecting an external aerial to your
receiver.
Theory and practice
One interesting phenomena is that aerial theory and
practice can be
surprisingly different.  Keeping common sense in mind it
is one of the few remaining areas for listeners to easily
experiment and often achieve fantastic results.
Whip aerial
Whip aerials can give fair results for casual listening to
the VHF/UHF bands.  For best results external aerials in
clear space are recommended.
Mounting location
It is important to mount any external aerial as high as
possible and in clear space although this is more important 
						

							AR5000 OPERATING MANUAL          PAGE 73
at VHF/UHF frequencies than for short wave.  If possible
the aerial should have a clear path to the horizon.  Results
are usually disappointing when an installation is in a loft
space.
Long wire aerials
For short wave reception, a random length of long wire
approximately 10 to 20 metres in length forms a good
compromise.  The wire should be connected to the centre
pin of ANT 1 (N-plug) or ANT 2 (SO239).  If possible try
to locate the receiver close to a window so that the wire
has the shortest and most direct run from the rear of the
receiver to the outside world.
Never attach the wire aerial directly to a support or wall.
Instead attach a short length (one metre) of insulating
material such as nylon to each support (house or tree for
example) and then onto the aerial wire.  Allow the wire
aerial to drop diagonally into the window and receiver
rather than straight down the wall.
Keeping the aerial away from supports and building will
reduce the loss of signal from the wire aerial and prevent
unwanted noise from entering the aerial system.
Magnetic balun long wire aerials are becoming very
popular as they allow coaxial cable to be used as the
down-lead from the wire aerial to the receiver.  The balun
transforms the impedance to a low level suitable for 50
OHM coaxial cable.  In this instance the path of feeder is
unimportant and chances of noise entering the aerial
system reduced.  The 50 OHM aerial input of the AR5000
is ideally suited for connection to a magnetic balun.
Dipoles
For the very best results you should consider a dedicated
aerial such as a single or multi-band dipole or similar aerial.
The problem with a wide coverage receiver like the
AR5000 is that for the ultimate results, many dedicated
aerials are required to cover the whole spectrum.  This
may involve complex aerial switching and reduces the
ability to quickly monitor many bands unless the automatic
aerial switching system is carefully planned using the
optional AS5000 aerial switch.
As a compromise it may be worth making up a dipole
aerial for one band of particular interest and have a
VHF-UHF discone plus second random wire for general
listening.It is quite easy to make a dipole for short wave, for that
matter one can be easily made up for VHF or UHF too.  If
being made for VHF-UHF, the centre connection of the
coaxial cable feeds the upper element set vertically.  Short
wave dipoles on the other hand are usually mounted
horizontally.
It is worth noting that dipoles are also quite effective on
two and three times their design frequency so you can
cover a few bands at once.  Reception using a half wave
dipole is best at 90 degrees to the direction the aerial is
laying, however if used at two or three times it’s
fundamental design frequency, reception is best closer to
the direction the aerial is lying.
A dipole has two legs running in opposite directions and
can be mounted vertically or horizontally (most VHF-UHF
activity is vertical). One leg is connected to the centre
conductor of the coaxial feeder cable while the other leg
is connected to the outer screen of the coaxial feeder
cable.  If mounted vertically, the centre of the coaxial feeder
should be connected to the leg facing upward.
A simple formula can be used to calculate the required
length of each leg for a half wave dipole:
            75
          --------               =  Length of each leg in metres
   Frequency in MHz
i.e.  For 14.2 MHz
           75
         -------       =  5.28 metres (i.e. the total length
         14.2                           of the aerial is twice 5.28m.)
For increased performance and directivity, additional
elements may be added to the front and rear of the dipole.
Directors - shorter than the dipole element and placed to
the front and a 
reflector - longer element to the rear.  Many
designs have been published for such aerials and
mathematical formulae may be used to calculate the
required length and spacing between elements.  This type
of aerial is usually refereed to as a yagi or beam.
Coaxial cables
When constructing dipole aerials or connecting VHF-UHF
aerials 50 OHM coaxial cable should be used.  For short
wave or short runs of VHF URM43, URM76 or RG58U
are ideal, for longer runs of VHF-UHF feeder it may be
worth considering a heavier URM67 or RG213 (or better!). 
						

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ATU & preselectors
Aerial tuning units (ATU) may improve the short wave
section of a wide
range receiver (such as the AR5000) by rejecting
unwanted signals and only allowing a specific band of
frequencies through.  These ATUs are normally
constructed in small boxes with about 3 controls on the
front. The disadvantage is the need to constantly retune
the ATU when changing frequency. An ATU of this nature
is 
passive, this means that no power is required to operate
the ATU and no extra circuit-noise is introduced into the
receiver.
Loop Aerials
Short wave desktop loop aerials have the advantage of
small size (such as the AOR LA320).  They too have tuning
controls to reject unwanted signals.  As the loop is within
easy reach of the operator it can be rotated to provide
directivity.  Loops can be particularly useful for DX’ing the
lower bands.
Generally speaking they offer excellent portability but
cannot compare on the higher bands with a well sited long
wire aerial.
Active aerials
Active aerials are normally quite compact (AOR WA7000)
and combine a wide coverage aerial (30 kHz - 2 GHz)
with a preamplifier mounted within the aerial its-self.  They
require power to enable them to operate.  Not all designs
allow you to switch the preamplifier off although some
have a gain control.
As with loop aerials they tend to provide good results on
the lower bands when compared to poorly sited short’ish
wire aerials.  Overload can be a problem on the busy 7
and 9 MHz bands.  If you have a small garden space,  an
active aerial may be worth considering.
Discone
For wide coverage in the VHF-UHF bands a compromise
has to be met and the most popular aerial is a discone
(AOR DA3000). Their appearance is like a large spider
or umbrella without the covering material, the better
models have about 16 elements.
Typical usable coverage starts from about 25 MHz and
extends continuously to 500 MHz, 1300 MHz or even 2000
MHz.  The coverage peaks and dips throughout it’s range
as the elements interact to provide the widest possible
coverage.  Due to their necessary construction discone
aerials are a little prone to 
wind noise due to vibration
and possible damage in severe gales.Stub filters
Should you encounter 
breakthrough when using an
external aerial (and the attenuator does not help) a simple
stub-filter placed in the coaxial cable may help.  This
comprises of a ‘T’ connector with an open circuit 50 OHM
cable length (the stub) attached to the ‘T’ piece.  A rough
calculation for the stub length is as follows:
(75 / Freq in MHz) x 0.67 = Stub length in metres
i.e. To reduce the strength of 88.3 MHz on VHF Band-II:
(75 / 88.3) x 0.67 = 0.57m or 57cm
Commercial filters - ABF125
A VHF civil AIRBAND FILTER is available from AOR
called the ABF125.  This will help minimise the possible
effects of breakthrough when listening to VHF airband in
BAND-II VHF high signal areas or when connected to
external aerials.
Other manufacturers are providing tunable filters to notch
out unwanted signals typically in the range of 75 to 175
MHz.
Earth systems
A separate EARTH connection made to the outer (braid)
connector of the ANT 1 or ANT 2 plug may improve aerial
efficiency and reduce noise.
Suitable earth points include connection to a water pipe,
central heating radiator or external earth rod.  If fitting a
separate external earth rod when your a.c. mains supply
uses a Protective Multiple Earth (PME) system, consider
the implications carefully.  If in doubt consult an
experienced electrician.
Connecting an external earth wire may greatly reduce the
local noise encountered when listening on the short wave
bands.  It is very important to provide a good earth should
you use an aerial tuning unit.
A short length of thick gauge earth wire may be connected
to a nearby central heating radiator or water pipe but never
use a gas pipe for earthing.  Ideally a separate earth
rod should be used but the length between the receiver
and rod becomes restrictive, if too long the earth system
may well 
pick up noise rather than remove it.
If a long run of earth wire is necessary, it may be worth
considering a 
screened earth system.  This simply
comprises a coaxial cable (such as URM43 or URM76
for short runs with URM67 or RG213 being used for longer
runs) shorted inner to outer at the earth rod end with only
the centre core connected to the outer of the AR5000
aerial plug,  the outer braid being cut back and insulated.
This provides a screen for potential incoming interference
and passes any noise down the cable away from the
receiver and toward the earth rod. 
						

							AR5000 OPERATING MANUAL          PAGE 75
(21)  Propagation - short wave bands
VHF and UHF transmissions generally only propagate
relatively short distances when compared to short wave
signals.  For all intensive purposes they may be considered
as line-of-sight 
plus a bit.
Where as point-to-point communication between mobile
users or when in built up areas may only be a couple of
kilometres, aircraft at heights of 9,000 metres may be
heard at a much greater distance (50 to 300 kilometres
or more with the right conditions).
Occasionally 
tropospheric weather conditions or
sporadic E layer ionisation enable VHF-UHF signals to
travel many hundreds of kilometres.
Unlike VHF and UHF transmissions which generally
propagate only on a localised basis (to the horizon plus a
small amount),  short wave transmissions may travel for
many thousands of kilometres.  Depending upon the
frequency in use, time of day, season of the year and sun
spot activity,  transmissions may propagate completely
around the world.
Radio signals are electromagnetic waves very similar to
light beams.  As such they do not readily follow the
curvature of the Earth but attempt to travel out into space.
The ionosphere
Luckily the frequency spectrum of short wave is often
reflected back down to Earth by the upper layer of the
Earth’s atmosphere called the 
ionosphere.
When the reflected signals reach the Earth again they
may either be received or reflected back up into space.  If
lucky, they will be reflected by the ionosphere yet again
down toward the Earth providing reception into another
and possibly more distant location.
The ionosphere is constructed of many layers of ionised
gas.  Of particular interest to short wave listeners’ are the
lower E and upper F1 & F2 layers although a lower D
layer exists during day time.
D layer
During day time the lower D layer 
forms around 60 to 80
kilometres above the Earth’s surface.  This D layer tends
to absorb low frequencies reducing the distance covered
by medium wave transmissions.  In the night time when
the D layer dissipates,  medium and low frequency
transmissions may propagate over much greater
distances.If the transmitted frequency is too high to be reflected by
the ionosphere,
or the angle too steep,  transmissions will simply pass
straight though the ionosphere without being reflected and
will travel upward to the next ionosphere layer.
E layer
Above the D layer is the E layer located at a height of
about 100 kilometres.  The E layer tends not to absorb
signals as much as the D layer but refracts some signal
back to Earth where it may be received some distance
from the original point of transmission.
Usually in Spring and Autumn, 
SPORADIC E propagation
consisting of dense pockets of E layer ionosphere, reflect
even the higher VHF and UHF transmissions causing
patterning on television sets.  This is to the delight of Radio
Amateurs who are then able to communicate for many
hundreds and even thousands of kilometres on frequency
bands usually capable of only local reception.
Occasionally a similar effect can be caused by
temperature inversion layers creating 
tropospheric
propagation
 selectively ducting transmissions between
two points.  Tropospheric propagation is usually applicable
to the higher VHF and UHF bands.
F1 & F2 layers
During the day time there are two upper layers of the
ionosphere,  these being the F1 layer at about 200
kilometres and the F2 layer at about 400 kilometres.  As
evening falls, these layers combine to form a single F layer.
It is F layer propagation that is largely responsible for short
wave propagation over great distances.
The density of the ionosphere layers varies depending
upon season, time of day and sunspot activity which is
believed to follow an eleven year cycle of good and bad
propagation conditions.
You will note that large areas of the Earth’s surface lays
between the point of transmission and reflection, in this
area there will be little or no reception.  For this reason F
layer propagation is often referred to as 
SKIP and the
reflected signal as 
SKY WAVE.
Generally speaking only frequencies below 30MHz are
reflected by the ionosphere.  Higher frequencies pass
straight through even the F layers and will continue outward
into space for ever.
Choice of frequency
Depending upon the time of day and desired skip distance,
different frequencies will be selected by Radio Amateurs
and Commercial users such as Oceanic Air Traffic, short
wave broadcast...
For instance the MUF (Maximum Usable Frequency) is
often stated for a path between two locations.  Choosing
a frequency above the MUF will not produce results as 
						

							PAGE  76          AR5000 OPERATING MANUAL
transmissions will pass straight into space.  MINimum
usable frequency is also stated for similar reasons.
Many propagation predictions and statistics are published
and usually available from most country’s National
Amateur Radio and short wave listeners representatives.
Various publications are produced giving transmission and
contact details for world-wide reception.  These titles
include:
World Radio TV Handbook (WRTH), BPI
Communications, 1515 Broadway, New York 10036, NY
USA.
Passport To World Band Radio, IBS North America, Box
300, Penn’s Park PA 18943, USA.
Listings for utility services are also widely published and
available.
(22)  Specification
ModelAR5000
Frequency range 10kHz ~ 2600MHz (minimum
accepted frequency input 5 kHz)
TuningNCO 1Hz ~ 999.999999kHz
Modes AM, FM, USB, LSB & CW
I.F frequencies 1st I.F. 622.0 MHz
2nd I.F. 10.7 MHz
3rd I.F. 455 kHz
Standard fitted filters 3kHz, 6kHz, 15kHz, 30kHz,
110kHz & 220kHz
(provision for 500Hz option)
Memory channels 1000 (100 ch x 10 banks)
Search banks 20 banks
Memory scan speed 25 channels per second in
standard mode, 45 channels per
second (max) in 
Cyber Scan
Search speed 25 increments per second in
standard mode, 45 increments
per second (with step size of
100kHz or less) in 
Cyber Search
PASS frequencies 2100 total (21 banks x 100 ch
inc VFO)
Priority 1 channel
I.F. output 10.7 MHz with maximum ± 5
MHz bandwidth
External reference 10.0 MHz input
Mute Phono/RCA socket CMOS input
pull-up to 5V @ 100k OHMS
Operating temp. 0° to +50° CAerial input 50 OHM unbalanced.  N-TYPE
& SO239
Audio output (13.5V) 1.7 WATT into 8 OHMS
@ 10% THD
Power requirements nominal 13.5V d.c. (12 ~ 16V)
@ 1A or less
Size 217(W) x 100(H) x 260mm(D)
mm approx excluding projections
Weight 3.5kg
CPU 8bit ROM 32,768 Byte
RAM 1,024 Byte
EEPROM131,072 Byte (1M Bit)
Selectivity
I.F. filter bandwidth table:
  Filter kHz Total nose Total skirt
                        (b’width kHz / dB)
   0.5 (500Hz)opt 0.5   -3 2.0   -60
   2.5 opt 2.5   -3 5.2   -60
   3 2.4   -6 4.5   -60
   5.5 opt 5.5   -3 11.0  -60
   6 9.0   -6 20    -50
   15 15    -6 30    -50
   30 30    -6 70    -50
   110 140   -3 350   -20
   220 260   -3 520   -20
Sensitivity
Receive frequency 10dB       12dB 12dB    12dB
S/N        SINAD    SINAD   SINAD
AM         SSB/CW   FM      FM
                          6kHz       3kHz     15kHz   220kHz
10kHz - 40kHz 63.00uV   17.70uV -        -
40kHz - 100kHz 4.46       1.25 -        -
100kHz - 2MHz 2.23       0.40 -        -
2MHz - 40MHz 1.25       0.40 0.56     1.58
40MHz - 1,000 MHz 0.63       0.3 0.4      1.25
1,000MHz -2.6 GHz 0.63       0.3 0.36     0.89
* Specification is typical but not guaranteed,
subject to change without notice due to
continuous development of the product E&OE.
Manual version 1.0. 
						

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