AOR AR8600 Receiver Manual

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All long range shipping and oceanic air traffic (as well as long range military aircraft) use USB.  DATA
modes such as RTTY, SITOR, PACKET, FAX etc may be resolved using USB.
SSB is a very efficient method of transmission as the unwanted second sideband and carrier have been
removed.  This allows the full transmitter power to be employed in conveying useful information within
the wanted sideband.  As a result, greater distances are possible on SSB with a smaller frequency
bandwidth being required than most other receive modes.
The AR8600 uses true carrier re-insertion and a dedicated SSB i.f. filter so that voice becomes
intelligible.  However due to the complexities of SSB,  audio never sounds 100% natural, like all SSB-
equipped receivers, the AR8600 may sound a little ‘robotic’ but you soon get used to SSB receivers.
Small tuning steps of 50 Hz or 100 Hz should be used for tuning in USB and the other similar modes
LSB & CW.
The AR8600 is a wide band receiver and as such cannot offer the receive performance of a
dedicated short wave receiver such as the AOR AR7030, this is mainly due to the limitation of
size.  The AR8600 will however provide adequate results for oceanic, ship to shore, amateur band
and general broadcast listening etc.
The SSB frequency display is not offset (like some other units), this is good for referencing to frequency
booklets and data bases.  However being such a compact wide band receiver, it will not be unusual for
the SSB display to be a few hundred Hz off frequency when listening to known frequencies such as
VOLMET (airband weather forecast service)... this is considered normal.
LSB
Lower Side Band -  The same comments apply as for USB.  By convention, radio amateurs use LSB
below 10 MHz.
CW
Continuous Wave - Often referred to a Carrier Wave or Morse code ‘dots and dashes’.  Commonly
used on the short wave bands by radio amateurs toward the lower end of each band allocation.  Some
commercial use is still made by shipping etc although its use is being phased out due to the introduction
of automated stations.
3-8  Changing tuning STEP size
The specification for channel occupancy, step (separation) and mode are decided by and allocated by
departments of Governments following International discussions.
Not surprisingly the allocation of frequency bands are not the same all over the world and channel
separation (step) varies from band to band.  As an example, the channel separation (step) for the
medium wave band in Europe is 9 kHz while in the U.S.A. it is 10 kHz.
For the above reasons it is necessary to alter the STEP size according to local bandplan conventions.
The AR8600 has been pre-programmed at the factory with all the bandplan data (specific to each market
area) so that the AR8600 will automatically select the appropriate step size and mode for the frequency
chosen.  This greatly simplifies operation of the receiver while you are familiarising yourself with all the
facilities.
The pre-programming of step size may be manually over-ridden so you may choose alternative settings
at will or when band plans are updated.
Section 3-7-2, 3-8 
						

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Should you wish to change the default tuning step size    .
The third main text line of the LCD will display the current default
size (perhaps “25.00” kHz).  If the reverse LCD legend “AUT”
displayed in the upper right corner of the LCD, this indicates that
AUTO MODE / STEP is currently selected.
The bottom line of the LCD displays the legend “STEP SET” to
indicate that the AR8600 is inviting you to change the step size.
Use the main dial or ï and ð keys to select the required step size.
The list is as follows: 0.05 kHz (50 Hz), 0.1 kHz (100 Hz), 0.2 kHz
(200 Hz), 0.5 kHz (500 Hz), 1.00 kHz, 2.00 kHz, 5.00 kHz, 6.25
kHz, 8.33 kHz, 9.00 kHz, 10.00 kHz, 12.50 kHz, 20 kHz, 25.00 kHz,
30 kHz, 50 kHz, 100.00 kHz.
To accept the displayed tuning step size 
 ,
the LCD will revert to its previous display.
&Note:  The frequency step of 8.33 kHz has been included
for compliance with the new VHF airband allocation, it has
been correctly implemented as eight-and-one-third kHz so that
no compound error arises (i.e. the last digits display 33, 66, 00).
The tuning step size may also be programmed in multiples of 50 Hz (via the keypad) so that unusual
step sizes other than stated are possible.  The acceptable step size range is 0.05 kHz (50 Hz) to
999.95 kHz in 50 Hz steps.
When the desired step size has been entered, 
 
 to accept the new step size.  If you attempt to input an invalid step
size, the error beep will sound (presuming that the beep facility is
enabled) and the incorrect input will be ignored.
 * Active frequency must be divisible by step size *
There is just one small point to bare in mind, the active frequency
must be divisible by the step size...  in 99% of cases they will be.
However, should you start experimenting with different step sizes
you may notice the active frequency change automatically to
the nearest multiple of step size as the AR8600 calculates
automatically for you, there is no need to carry a calculator!
For example, select 118.000 MHz then select a 9 kHz step size:
       
    choose “9.00” using the main dial then  
The receive frequency will currently be displayed as 118.000 MHz but once the main dial has been used,
the displayed frequency will be corrected to 117.9990 or 118.0080 MHz (depending upon the direction of
tuning) both of which are the closest multiple of 9 kHz to 118 MHz.
Section 3-8 
						

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The display doesn’t correct immediately upon frequency entry to allow you to enter the ‘STEP-ADJUST’
menu to change the step size and step-adjust in order to help track unusual band plans.
&Note: AUTO-STEP, STEP-ADJUST and AUTO-MODE are linked to the pre-programmed
bandplan data.  When one of the parameters is changed from the default “AUTO” the bandplan
will be ignored.
To reinstate AUTO step size, the receive MODE must be returned to “AUTO” using the “MODE SET”
menu or by using the key sequence 
   
3-9  STEP-adjust
The AR8600 provides a powerful feature to enable accurate
following of unusual band plans.  When active, the “ADJ” legend is
displayed top-centre of the LCD.
Step-adjust is used when the receiving frequency is not divisible
by the step size in use (It is possible that step-adjust has been
programmed into the auto-mode bandplan data for some world
market areas).  Therefore step-adjust is useful for certain band
plans such as cellular which in some areas starts as 917.0125 MHz then increments in 25 kHz steps.
Another example is the CB allocation in certain areas which starts at 27.60125 MHz then increments in
10 kHz steps.  Often just a HALF STEP is required but more exotic band plans can be tracked.
Step-adjust may be factory pre-programmed into the bandplan data (you may override this).  It is also
possible to store the step-adjust data into memory channels and search banks.
3-9-1  Automatic calculation of step adjust
The AR8600 can calculate the required step-adjust, simplifying its use.
Example 1: Assume that you wish to tune from 148.010 MHz in 20 kHz steps (i.e. 148.010, 148.030,
148,050, 148.070, 148.090 etc).  When manually tuning, the AR8600 would normally correct the
frequency display to read 148.020 then step upward in 20 kHz steps.  Tuning back downward will skip
148.010 MHz (the starting point) as the original frequency was not divisible by step size… it was
offset by +10 kHz.  Usually the frequency must be divisible by the tuning step size.  However, the
STEP-ADJUST facility is used to address this situation.
With the above example of 148.010 MHz with 20 kHz steps in mind, while in VFO mode, key in the start
frequency of 148.010 MHz
Section 3-8, 3-9, 3-9-1 
						

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Access the STEP menu using the key sequence
   .  Use the main dial to
select a step size of 20 kHz (do NOT press enter!).
  to access the STEP-ADJUST menu.
Accessing this menu will activate the step-adjust facility,
the “ADJ” legend will be displayed on the LCD
to confirm selection.  You will note that the
calculated step adjust value is displayed on the
bottom of the LCD as “ADJ+ 10.00” representing
a positive offset of +10 kHz with a step size of
20 kHz.  
  to accept the
displayed data.
The display will return to VFO mode with 148.010
MHz displayed.  The main dial will now correctly
follow the required bandplan.
3-9-2  Cancelling step-adjust
There are two ways to cancel step-adjust
1.  Access the STEP menu.  
   , the step-adjust data will be
immediately displayed along with step size.  
  to remove the step-adjust data
from the display, the “ADJ” legend will be removed from the LCD.  
  to accept
the changes.  Step-adjust will be cancelled.
2.  Presuming that you have manually selected step-adjust (step-adjust has not been set by the
auto-mode bandplan), reselect AUTO-MODE which will reinstate the auto-mode step size, step-
adjust, frequency offset and receive mode.  
   .  The “ADJ”
legend will be removed from the LCD and the auto-mode “AUT” legend will be displayed.
3-9-3  Manual setting of step-adjust
The AR8600 usually correctly ‘guesses’ what step-adjust you require, often this is a half step but manual
intervention is possible!
Example 2: Assume that you wish to tune from 58.445 MHz in 15 kHz steps (i.e. 58.445, 58.460,
58.475, 58.490, 58.505 etc).  When manually tuning, the AR8600 would normally correct the frequency
display to read 58.455 then step upward in 15 kHz steps.  Tuning back downward will skip 58.445 MHz
(the starting point) as the original frequency was not divisible by step size… it was offset by +5 kHz.
Usually the frequency must be divisible by the tuning step size.
Section 3-9-1, 3-9-2, 3-9-3 
						

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However, the STEP-ADJUST facility is used to address this situation.
With the above in mind, 58.445 MHz with 15 kHz steps in mind, while in VFO mode, key in the start
frequency of 58.445 MHz
         
   
Access the STEP menu using the key sequence    .  15 kHz is not a
standard size provided by rotating the main dial so key in the required 15 kHz step size.
  
    (do NOT press enter!).    to access the
STEP-ADJUST menu.  Accessing this menu will activate the step-adjust facility, the “ADJ” legend will be
displayed on the LCD to confirm selection.  You will note that a calculated step-adjust value is displayed
on the bottom of the LCD as “ADJ+ 7.50” representing a positive offset of +7.5 kHz with a step size of 15
kHz… the AR8600 often assumes that you require a half step.  However when looking at the
requirement the required offset is actually 5 kHz.  
 ò to move the cursor to the step-adjust
(bottom) line.  Use the main dial to select 5.00 kHz (or key in 5 kHz 
 ).
 
  to accept the displayed data.  The display will return to VFO mode with 58.445 MHz
displayed.  The main dial will now correctly follow the required bandplan.
Manual intervention is not always required
Note:  The AR8600 is not dumb, in the above example, as soon as you pressed the 
key the CPU realised that a half step was not appropriate so would have selected an offset of
5 kHz automatically!  Try it and see, just 
  while it displays 7.50 kHz - yes,
it works!  Access the step menu to review the figures, they will show a step size of 15 kHz and
step-adjust of 5 kHz… clever!
Example 3: This example shows just how bizarre the bandplan can be.  Assume that you wish to tune
from 145.210 MHz in 14 kHz steps (i.e. 145.210, 145.224, 145.238, 145.252, 145.266 etc).  When
manually tuning, the AR8600 would normally correct the frequency display to read 145.236 then step
upward in 14 kHz steps.  Tuning back downward will skip 145.210 MHz (the starting point) as the original
frequency was not divisible by step size.
Section 3-9-3 
						

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With this example of 145.210 MHz with 14 kHz steps in mind, while in VFO mode, key in the start
frequency of 145.210 MHz
         
   
Access the STEP menu using the key sequence    .  14 kHz is not a
standard size provided by rotating the main dial so key in the required 15 kHz step size.
    (do NOT press enter!).
  to access the STEP-ADJUST menu.  Ignore the step-adjust value displayed (10 kHz),
  to let the AR8600 automatically calculate the requirement, you will need to
  a second time to exit the menu and return to frequency display.
The frequency of 145.210 MHz will be displayed and the main dial will now correctly follow the required
bandplan, 14 kHz steps 145.224, 145.238 MHz etc.  For your information, the required step-adjust was
2 kHz.   If you wish, access the step menu to review the figures, they will show a step size of 14 kHz and
step-adjust of 2 kHz… right again!
3-10  FREQUENCY OFFSET
This facility enables receive frequency to be quickly SHIFTED (two key presses) by a predetermined
value, this makes it easy to track duplex-transmissions or check repeater inputs / outputs.  Offset
frequencies may be factory pre-programmed into the auto-mode bandplan data for some world market
areas.  Frequency offset may also be programmed manually.
The locations for frequency offset storage are numbered 00 to 47 with 00 acting as OFF, this makes 47
locations available.  Locations 01 to 19 may be programmed by the operator while locations 20 to 47 are
reserved for factory programming (used by the auto bandplan data).  Look at locations 20 to 47 for
common offsets, they may already be stored.
Frequency offset may be programmed into VFO, memory channel and search banks.  It is most
convenient to set-up in VFO mode then save the data to specific memory channels for quick recall at a
later date.  Frequency offset is primarily designed for memory channel use, it may appear rather long
winded to toggle on/off in VFO mode.  However even when programmed, frequency offset is in no way
detrimental to normal operation.
The acceptable range of frequency offset is 0 MHz to 999.99 MHz, of course if the offset is set to 0 MHz,
the frequency will not change!  Before the FREQUENCY OFFSET facility can be used, it first needs to
be configured (unless factory programmed for certain bands).
3-10-1  Using pre-programmed frequency offset data
To access the frequency offset set-up menu    
Section 3-9-3, 3-10, 3-10-1 
						

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The third line will display “OFFSET 00” with “00”
indicating that frequency offset is currently off,
there will be no “DUP” legend displayed when the
frequency offset is OFF.  The bottom line of LCD
will display “- - - . - - - -“ indicating that no offset
is stored.  Use the main dial or ï ð keys to
review the offset locations, particularly numbers
20 to 47 where useful factory
programmed offsets may be stored.
As soon as you shift from location
00, the “DUP” duplex legend is
displayed on the LCD to indicate that frequency offset is in use.
Presuming that data is already programmed into an offset location,
 the  key to toggle offset between “+” positive and
“-“ negative offset, this is a 
global toggle and affects ALL
frequency offset channels (but not those already stored into
memory or search banks).  To accept the offset setting, 
.  The LCD will revert to its operation prior to the
frequency offset menu being called.  The LCD legend “DUP” will
be displayed to indicate that frequency offset has been activated.
To use the frequency offset 
 , the LCD frequency
will alter to take account of the offset ‘value & direction’ and the
squelch will be defeated.  When you release the 
 key, the
AR8600 will revert to the original frequency (and squelch will close
if no signal is present).
&Note: Each VFO, memory channel and search bank can be programmed with a different
frequency offset.  If different channels and offsets have been programmed to VFOs etc, the
key sequence 
    will recall the specific offset location
originally used during programming, this is particularly useful when you simply wish to toggle
the + / - offset.
To cancel the frequency offset, access the frequency offset menu and select location “00”, the “DUP”
legend will be removed from the LCD.
3-10-2  Entering new frequency offset data
Assume that you are in VFO mode with a frequency of 433.000 MHz
To access the frequency offset set-up menu 
   
The third line will display “OFFSET 00” with “00” if the frequency offset is currently off, there will be no
“DUP” legend displayed when the frequency offset is OFF.
Use the main dial or ï ð keys to select an unused frequency offset location between the numbers of
01 and 19 inclusive (00 being interpreted as off and 20 - 47 reserved for pre-programmed data).
Section 3-10-1, 3-10-2 
						

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For example, use the main dial until the LCD displays “OFFSET 01”, the bottom line of LCD will display
“- - - . - - - -“ indicating that no offset has been previously stored.  If data is stored, the offset value will be
displayed on the bottom line of the LCD and may be overridden.
Key in the desired offset in MHz format, the ð key may be used as a backspace should an error be
made.  i.e. for an offset of +1.600 MHz 
      (don’t
push enter!)  
 the  key to toggle the frequency offset direction between “+” and “-“ until
the LCD shown “+” for positive offset.  You may use the ñ key to accept the frequency but stay in the
menu (in case you haven’t yet decided on the direction of offset), 
  to accept the data
input.
The LCD will revert to its operation prior to the frequency offset menu being called.  The LCD legend
“DUP” will be displayed to indicate that frequency offset has been activated.
To use the frequency offset 
 , the LCD frequency of 433.000 MHz will alter to take
account of the offset value and direction and the squelch will be defeated, the duplex frequency of
434.600 MHz (which is 1.600 MHz above the original frequency) will be displayed.  When you release
the 
 key, the AR8600 will revert to the original frequency of 433.000 MHz (and squelch will close
if no signal is present).  You can access the frequency offset menu simply to change the direction of
offset from “+” to “-“ or vice-versa.
3-11  Attenuator
The attenuator adds 10dB of signal reduction to the RF input stages of the AR8600 to reduce the
possible effects of strong signal overloading due to connection to an external aerial or when the receiver
is used in close proximity to strong transmissions.
The AR8600 has two settings for ATT (attenuator), on and off.
When the attenuator is ON, the legend “AT T” appears on upper left
of the LCD.
To toggle the attenuator on/off 
  
  The legend “AT T” confirms selection and incoming
signals will be reduced in strength.  To toggle on/off again just
repeat the sequence 
   , the
legend “AT T” is extinguished when the attenuator is OFF.
The selection of attenuator is held separately in each VFO, each memory channel and may also be
toggled 
during search (in scan mode, the scanning process must be stopped in order to see which
memory channel you are applying the attenuator to!).
3-12  Noise limiter
The noise limiter can help to reduce the effects of noise spikes and pulses while listening in AM and
SSB modes (WAM, AM, NAM, USB, LSB, CW).  The noise limiter may be toggled on/off in all receive
modes but will only be operational in the AM and SSB modes, it will have no effect on WFM, NFM or
SFM.
Section 3-10-2, 3-11, 3-12 
						

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The noise limiter has two settings, on and off.  When the noise
limiter is ON, the legend “NL” appears on LCD.
To toggle the noise limiter on/off 
  
  The legend “NL” confirms selection and the noise limiter
will be active in AM and SSB modes.  To toggle on/off again just
repeat the sequence 
   , the
legend “NL” is extinguished when the noise limiter is OFF.
The selection of noise limiter is held separately in each VFO, each memory channel and may also be
toggled during search (in scan mode, the scanning process must be stopped in order to see which
memory channel you are applying the noise limiter to!).
3-13  AFC - Automatic Frequency Control
The AR8600 is equipped with AFC, this is useful when tracking unusual band plans or when the exact
frequency is unknown… it ensures that the AR8600 is tuned to ‘centre frequency’ for best reception.
AFC is operational only in NFM, SFM, WAM, AM, NAM… AFC is not operational in WFM, USB,
LSB, CW.   If AFC has been activated and you select a mode not supported by AFC, the “AFC” legend
will be extinguished from the LCD.  Once AFC has been activated (say when you are monitoring NFM),
it will temporarily be deactivated should you select WFM, USB, LSB, CW but will automatically be
reactivated when NFM or other supported modes are again selected.
VALID = NFM, SFM, WAM, AM, NAM
INVALID = WFM, USB, LSB, CW
AFC has two settings, on and off.  When AFC is ON, the legend
“AFC” appears on LCD during reception using a supported receive
mode.
&Note: Attempted operation while using an unsupported
receive mode will result in the input being ignored, however the
on/off toggle status will be incremented and implemented once
a supported receive mode is selected (i.e. you can always
toggle the AFC status on/off regardless of displayed mode).
To toggle AFC on/off 
   , the legend “AFC” confirms selection when a
supported receive mode is in use.  To toggle on/off again just repeat the sequence 
 
 , the legend “AFC” is extinguished when AFC is OFF and using a supported receive
mode.
The selection of AFC is held separately in each VFO, each memory channel and may also be toggled
during search (in scan mode, the scanning process must be stopped in order to see which memory
channel you are applying the AFC to!).
AFC characteristics
When the AFC is active while monitoring a transmission using a supported receive mode, AFC will
attempt to automatically ‘pull’ the AR8600 onto centre frequency for best reception.
Section 3-12, 3-13 
						

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The distance in kHz which the AR8600 can ‘pull’ depends upon receive mode, IF bandwidth and signal
strength… the wider the filter and stronger the signal then the further AFC can pull.
Typically AFC will pull in the region of ± 5 kHz to ± 15 kHz, the maximum value for AFC is set to
± 25 kHz so that the receiver does not continually tune across the frequency spectrum looking for
‘anything’ to centre tune.
The AFC process usually takes a few seconds to ‘settle down’ after which time it is normal for the
frequency display last couple of digits to flicker up and down in frequency... this looks like ‘frequency
drift’ but fear not, the frequency tracking is under strict control!  Typical accuracy of centre tuning is
around 1.5 kHz.  If no signal is present and the squelch is open, the last two digits will randomly flicker
around. When the squelch closes in the absence of a signal, the last two digits will stop flickering but
may display a frequency which does not strictly adhere to the bandplan.  If you toggle AFC off, the
frequency display will jump to the nearest increment for the frequency band (appropriate to the tuning
step selected).
Section 3-13