QED PL3 User manual

INTERFACION PTY LTD
ACN: 614 858 990
P O BOX 106 R, REDAN VIC 3350. AUSTRALIA
QED –PL3
(With the August 2019 QED Software Update)
OWNERS MANUAL
Proudly made in Ballarat, Victoria, Australia
QED image is for illustration purposes only

2
QED INTRODUCTION
Congratulations on your purchase of the QED Pulse Induction metal
detector. The QED has been engineered specifically to make your
prospecting experience more rewarding.
Whenever you purchase any new technology, there is no point in just
looking at it, or putting it away in the wardrobe. You need to explore
all the new functions and settings to maximize your understanding and
the potential of the device.
If you are an experienced operator, you may find the settings to be
different to anything you have previously used. Whether you are a first
timer or an experienced operator, your confidence will develop as you
master the QED.
Read these instructions carefully to master the QED’s full potential. Be
confident to alter and adjust your settings over known targets until you
have a working understanding of the detector’s potential and character.
This detector has an expansive range of possible settings, and as you
become familiar with all the functions you will maximize your potential
to find gold or relics in even the harshest ground.
Happy hunting

3
DOCUMENT CHANGE CONTROL
Date Document Revised
Version
Nov 2018
QED –PL2 OWNERS MANUAL V 2.0
Dec 2018
QED –PL2 OWNERS MANUAL V 3.0
Dec 2018
QED –PL2 OWNERS MANUAL V 4.0
Jan 2019
QED –PL2 OWNERS MANUAL V 5.0
Jan 2019
QED –PL2 OWNERS MANUAL V 6.0
Aug 2019 (2019 QED Upgrade)
QED –PL2 OWNERS MANUAL V 7.0
Jan 2020
QED –PL2 OWNERS MANUAL V 7.1
May 2020
QED –PL3 OWNERS MANUAL V 1.0
TABLE OF CONTENTS
QED INTRODUCTION.................................................................................... 2
DOCUMENT CHANGE CONTROL............................................................................ 3
TABLE OF CONTENTS............................................................................................. 3
NAVIGATING THE CONTROL INTERFACE ............................................................... 7
START UP............................................................................................................... 8
MENU OPTIONS..................................................................................................... 9
FACTORY DEFAULTS .............................................................................................. 9
QED Software Updates Changes .........................................................................10
QUICK START GUIDE............................................................................................ 11
CONTROL COMMANDS ....................................................................................... 12
MENU CONTROLS................................................................................................ 13
1: MANUAL GND BAL (MGB) .......................................................................... 13
Description..................................................................................................13
YouTube Reference................................................................................. 14
Unable to Ground Balance ......................................................................... 14
Rechecking Ground Balance whilst detecting ............................................ 14
YouTube Reference................................................................................. 14
Notes........................................................................................................... 15
ADVANCED GROUND BALANCE (MGB) TECHNIQUE ...................................... 15
Description..................................................................................................15

4
Notes........................................................................................................... 15
AUTO GND BAL (AGB)..................................................................................... 16
Description..................................................................................................16
YouTube Reference..................................................................................... 16
Notes........................................................................................................... 16
2. THRESHOLD B –(THS-B) (BIAS)...................................................................17
History of THS-B and NULL .........................................................................17
Description..................................................................................................18
Navigating to Threshold B ..........................................................................18
YouTube Reference..................................................................................... 19
Threshold B NULL Position ......................................................................... 19
YouTube Reference..................................................................................... 19
Small Search Coils....................................................................................... 19
Medium Search Coils .................................................................................. 20
Large Search Coils ....................................................................................... 20
Notes........................................................................................................... 20
3: THRESHOLD A –(THS-A) (VOLUME) ........................................................... 21
Description..................................................................................................21
Adjusting..................................................................................................... 21
Threshold A................................................................................................. 21
YouTube Reference..................................................................................... 21
Notes........................................................................................................... 21
4: GAIN............................................................................................................ 22
Description..................................................................................................22
Adjusting Gain............................................................................................. 22
YouTube Reference..................................................................................... 22
Notes........................................................................................................... 22
5: MODE.......................................................................................................... 23
Description..................................................................................................23
Beach Mode................................................................................................ 23
Adjusting Mode .......................................................................................... 24
Youtube Reference ..................................................................................... 24
Notes........................................................................................................... 24
6: SMF (STATIC MAGNETIC FIELDS) ................................................................ 25
Description..................................................................................................25
Adjusting SMF............................................................................................. 25

5
YouTube Reference..................................................................................... 25
Notes........................................................................................................... 25
7: BATTERY......................................................................................................26
Description..................................................................................................26
Fitting the Batteries.................................................................................... 27
Charging Li Ion Batteries............................................................................. 28
Lithium (li ion) Battery Care .......................................................................28
Notes........................................................................................................... 28
8: PITCH........................................................................................................... 29
Description..................................................................................................29
Adjusting Pitch............................................................................................ 29
YouTube Reference..................................................................................... 29
Notes........................................................................................................... 29
9: SMR (SYNCHRONOUS MAINS REJECTION) ................................................. 30
Description..................................................................................................30
YouTube Reference..................................................................................... 30
Notes........................................................................................................... 30
FERRITE EMI SUPPRESSORS................................................................................. 31
STANDARD SPEAKER ........................................................................................... 32
SEARCH COIL TYPES............................................................................................. 33
ADVANCED SETUP GUIDE.................................................................................... 34
HOW TO SEARCH THE GROUND .......................................................................... 35
FINE TUNING EXERCISE ....................................................................................... 36
QED Setup Procedure.......................................................................................... 37
OPTIONAL QED BATTERY EXTENDER................................................................... 40
ADDITIONAL INSTRUCTIONAL VIDEOS ................................................................ 42
Effects of adjusting Gain, Threshold A and Threshold B ................................ 42
Effects of adjusting Threshold B for selected target size............................... 42
Additional Videos by Goldman....................................................................... 42
Additional QED Web Resources .......................................................................... 42
TECHNICAL SPECIFICATIONS................................................................................ 43
MANUFACTURER’S WARRANTY .......................................................................... 44
QED TIPS.............................................................................................................. 45
Coil Choice ...................................................................................................... 45
THS-B............................................................................................................... 45
THS-B and rising pitch targets ........................................................................ 46

6
Factory Preset Values and THS-B....................................................................46
THS-A and THS-B relationship ........................................................................47
Ground noise identification with the latest 2019 upgrade............................ 47
QED and EMI................................................................................................... 48
Ground Balancing with the latest 2019 upgrade ........................................... 48
Manual Ground Balance (MGB) .....................................................................48
QED factory Default Setting ........................................................................... 49
QED and powerlines ....................................................................................... 49
QED Fuse......................................................................................................... 50
Rising vs falling pitch targets.......................................................................... 50
Targets with a long and narrow profile.......................................................... 50
Audio Recovery............................................................................................... 51
Beach Mode.................................................................................................... 51
THS-B NULL Variance...................................................................................... 51
Abnormally Noisy QED ................................................................................... 52
Checking/adjusting Ground Balance on the fly whilst detecting................... 52
Ground Balance Leeway................................................................................. 53
Changing Mode............................................................................................... 53
Detection Hole................................................................................................ 53
Low battery voltage........................................................................................ 54
Charging Your QED ......................................................................................... 55
Charging Your QED battery extender pack..................................................... 55
NOTES ................................................................................................................. 56

7
NAVIGATING THE CONTROL INTERFACE
The button Triangle image on the control box is the TURN ON BUTTON and INCREASE
ADJUSTMENT button.
The button Triangle image on the control box is the DECREASE ADJUSTMENT button.
Use the button to TOGGLE between menu Item Select and Menu Item Adjustment.
Press and hold the button to TURN OFF the detector.
Click on this YouTube link to view an explanation of the QED Control Panel functions.
The display is an all
lighting conditions
3-digit LED backlit
LCD display.

8
START UP
Note: As the QED is marketed in various configurations, these steps are indicative only.
Step 1
Connect a suitable coil.
Step 2
Insert Batteries or connect Battery Pack
Step 3
Turn Detector ON by pressing the BUTTON.
Turn ON the remote SPEAKER pressing the button at side of the speaker housing.
Step 4
Scroll through adjustment menu item numbers by pressing either buttons.
When on the required adjustment menu item number press the button
Step 5
INCREASE variable using or DECREASE using
Step 6
To return to variable menu press the button.
Step 7
To turn detector OFF, press and hold the button and current adjustment settings will be
saved.
Step 8
To reload Factory Default Settings,
•Set the Gain to any number other than 001; or set Mode to any Mode other than 003
•Turn the detector OFF
•Then PRESS and HOLD the button while pressing the button.
•Check Gain, if set to 001 (or Mode is 003), then the Factory Reset has been successful.

9
MENU OPTIONS
1: Manual Ground Balance
2: Threshold B (Bias)
3: Threshold A (Volume)
4: Gain
5: Mode
6: Static Magnetic Fields (SMF)
7: Battery
8: Pitch
9: Synchronous Mains Rejection (SMR)
FACTORY DEFAULTS
Setting
Range
Factory
Default
Manual Ground Balance
1 - 300
150
Threshold B (Bias)
1 –99
50
Threshold A (Volume)
1 –90
30
Gain
1 –10
1
Mode
Gold Detecting in
Mineralised Ground
1 –10
3
Beach Mode
11
3
Static Magnetic Fields (SMF)
1 –100
50
Battery
Displays:
~5.98v –9.99v
Pitch
1 –50
25
Synchronous Mains Rejection (SMR)
1 –200
107

10
QED Software Updates Changes
The Aug 19 Software update introduced the following changes:
1. a significantly different and arguably a much better Ground Balance Technology (called DSM) than the
previous technology, with an expanded MGB Range and Default as per below.
2. Along with this change, the number of Modes was reduced from a total of 16 to a total of 11.
3. In addition, the QED was modified to enable the use of DD Coils.
Setting
Pre-Aug 19 Update
Aug 19 Update
Range
Default
Range
Default
Manual Ground Balance
1 - 200
100
1 - 300
150
Threshold B (Bias)
1 –99
50
1 –99
50
Threshold A (Volume)
1 –90
30
1 –90
30
Gain
1 –10
1
1 –10
1
Mode
Gold Detecting Modes
1 - 15
3
1 –10
3
Beach Mode
16
3
11
3
Static Magnetic Fields (SMF)
1 –100
50
1 –100
50
Battery
Displays:
~5.98v –
9.99v
Displays:
~5.98v –
9.99v
Pitch
1 –50
25
1 –50
25
Synchronous Mains Rejection (SMR)
1 –200
107
1 –200
107
Tip:
To determine whether your QED has had the Aug 19 Update applied, check the number of Modes.
If a maximum of 11, then the QED has been updated with the Aug 19 update.

11
QUICK START GUIDE
For people new to the QED, use the following Quick Start Guide to start detecting as quickly as possible
without having to understand all of the available settings and when/why to use them.
When you feel confident in using the QED and wish to adjust the various QED settings based on coil size,
ground conditions, and target type (small; all; large) to name a few, then refer to the Advanced Setup Guide.
Step
Description
Turn the detector ON by performing a Factory Reset
Mode
Factory Default (3)
Ground Balance
•MGB
THS B
Set to NULL
THS A
Start at Factory Default (30) and increase until a (slight)
threshold is heard
GAIN
Start at Factory Default (1) and increase GAIN as high
as prevailing EMI conditions and Ground Type will
allow.
Re-Ground Balance
•MGB, or
•AGB
Target
Response
Get a 5c coin and a $1 coin and set them approximately 60 cm apart.
•Swing over the 5c coin and you will get a high then low target response
•Swing over the $1 coin and you will get a low then high target response
Learn to recognise these different signals as they will assist you in performing the MGB and in
addition indicate the size (gold) target under the coil. A nugget that is less than approximately
2.5 gm will give a High/Low, whereas a nugget larger than 2.5/3gm will give a Low/High target
response
These coins are very similar in size but are either side of the ground balance (detection) hole,
thus give a different response.
Notes
Tip:
Once you have adjusted the detector to suit, leave the detector in the MGB adjustment
setting so that you can quickly adjust the GB whilst you are detecting.

12
CONTROL COMMANDS
TURN THE DETECTOR ON
Ensure the battery power lead is connected to the lead socket on
the control box
PRESS the once to turn the detector on.
Click on this YouTube link to see how to turn the QED on.
Note: The detector serial Number appears on the screen for a fraction of
a second after switch on
CYCLE THROUGH MAIN
MENU OPTIONS
PRESS either the Button or the button to toggle through the
Main Menu options (1-9)
TOGGLE BETWEEN A MENU
ITEM NUMBER OR ADJUST
VARIABLE
Pressing the button toggles between displaying the menu
item number or a variable adjustment.
Note:
•A single digit is the menu item number
•Three digits indicates variable adjust mode
Click on this YouTube link to view an explanation of the QED
Control Panel functions.
INCREASE OR DECREASE A
VARIABLE (e.g. GRD BAL)
Press the button to increase a variable number
Press the button to decrease a variable number
TURN THE DETECTOR OFF
PRESS and HOLD the button for three seconds
Click on this YouTube link to see how to turn the QED off.
FACTORY RESET
Note: The factory reset can only be performed with the detector switched
OFF
PRESS and HOLD the button, then press the button for 2
seconds, then release both buttons.
Click on this YouTube link to see how to perform a Factory reset
Note: The Factory Reset will set your THS-B to 50, which may not be your
THS-B NULL point and as a result the QED may be noisy. If this is
the case, simply adjust THS-B to NULL to quieten your QED before
readjusting other settings.
Tip:
Before doing a Factory Reset
(FR) set THS-A to anything but
30 before the detector is turned
off.
Once the detector has been
reset, if THS-A is 30 then the FR
has been done correctly.
Tip:
To quickly get back to the MGB
adjustment screen from any
setting, momentarily push the
AGB button.

13
MENU CONTROLS
1: MANUAL GND BAL (MGB)
Setting range 1-300
Factory preset at 150
Description
The detector will respond
to the natural
mineralization of the soil
and provide the operator
with false signals.
It is necessary to Ground
Balance the detector to
only register the signals
generated by metal
targets.
MGB Prerequisites:
✓Before trying to MGB, swing the coil over the ground to make sure there
are no metal targets under the coil, and
✓Wait until the audio settles/recovers before lowering the coil to the ground.
The Manual Ground Balance procedure is as follows:
•Select Menu Item # 1 (MGB), then press the button
to open the MGB setting.
There are two methods to determine which direction to MGB (either up
or down):
1. Perform an AGB and note which direction the AGB moves, either
up or down from the current MGB number, or
2. From approximately 6”, slowly move the coil towards the ground
and take note of the audio tone as the coil is in the DOWNWARD
motion:
oIf the audio on the downward motion is a LOW tone, then you will need
to increase the MGB
oIf the audio on the downward motion is a HIGH tone, then you will
need decrease the MGB
MGB Process
1. If you need to go up to MGB, then hold the button depressed
whilst very slowly bobbing the coil up and down until the QED is
quiet. It is very important to wait for the audio to recover during
the bobbing motion before continuing to bob the coil.
2. If you need to go down to MGB, then hold the button
depressed whilst very slowly bobbing the coil up and down until
the QED is quiet. It is very important to wait for the audio to
recover during the bobbing motion before continuing to bob the
coil.
3. When the tone has faded to a minimum, the detector will be
ground balanced.
4. You may need to incrementally adjust the MGB either up or down
a few clicks to achieve the final (perfect) GB.
Tip:
The or buttons
can either be:
•Held in if there is a
large difference
between the ground
and the current
ground balance
setting, or
•incrementally
adjusted to achieve
the MGB.

14
MENU CONTROLS
1: MANUAL GND BAL (MGB)
Setting range 1-300
Factory preset at 150
YouTube Reference
Click on this YouTube link to see how to Manually Ground Balance (MGB)
the QED.
Unable to Ground Balance
If the Ground Balance (GB) is too difficult to achieve or after setting the
Ground Balance the detector becomes noisy for no apparent reason:
1. Try to GB by adjusting the MODE to between 6 –10 as this will
help reduce the feedback from hot mineralization pockets of
ground
2. Furthermore, keeping the search coil 1 inch off the ground when
detecting can help stabilize the detector at the cost of losing
some sensitivity on some targets
Note: Higher Mode settings can reduce the audio response on very small
targets
Rechecking Ground Balance
whilst detecting
To recheck the ground balance, tilt/lift the coil at the end of each
left/right swing as you are detecting and take note of the audio
response:
1. If there is no response, then continue detecting as the detector
is Ground Balanced.
2. If there is a RISING response, use the button to increase the
MGB a couple of clicks (at a time) until the audio response is
reduced to a minimum.
3. If there is a DIPPING response, use the button to decrease
the MGB a couple of clicks (at a time) until the audio response is
reduced to a minimum.
YouTube Reference
Click on this YouTube link to see how to Recheck the Ground Balance
whilst detecting.
Tip:
This method is the
reverse of the normal
MGB process, as using
this method you will
need to raise the MGB if
you get a high tone and
lower the MGB if you get
a low tone.
This is because you are
listening for the tone as
you raise the coil, not
lowering the coil.

15
MENU CONTROLS
1: MANUAL GND BAL (MGB)
Setting range 1-300
Factory preset at 150
Notes
ADVANCED GROUND BALANCE (MGB) TECHNIQUE
Description
When detecting extremely variable ground there is a method to prevent
wasting time digging “ground noises”.
1. While swinging the coil take note of the response to determine
either rising or falling pitch.
2. If the pitch rises, toggle the MGB DOWN 20 counts (or UP 20
counts if the pitch falls) then swing over the patch again.
If the signal has diminished, has disappeared or has moved then don’t
bother digging, it’s a ground noise.
Restore MGB to previous value and continue detecting.
Notes
Tip:
A (real) Target will not be
‘balanced’ out by the +-
20 method, even if going
+-30 (or more) to
determine the status of a
target response.

16
AUTO GND BAL (AGB)
Setting range 1-300
Factory preset at 150
Description
The Auto Ground Balance (AGB) procedure is now only used to
determine the direction (either up or down) for a User to perform a Manual
Ground Balance (MGB):
•Hold the coil about 15" off the ground, press and hold the AGB
button while lowering the coil in a very fast motion.
•The AGB Button MUST be released when the coil is about 3"
from the ground.
Note: Do not hit the search coil with the ground surface as this can produce
unexpected results when trying to ground balance the detector.
YouTube Reference
Click on this YouTube link to see how to Auto Ground Balance the
QED.
Notes
Tip:
Always set THS-B to
NULL to perform an
AGB

17
2. THRESHOLD B –(THS-B) (BIAS)
Setting range 1-99
Factory preset at 50
History of THS-B and NULL
To explain what THS-B NULL is, I need to first explain what the Ground
Balance is actually doing.
The Mineralised ground in our goldfields produces a reaction in the
detector the same as a target response. However, this base response
can be neutralised (NULLED) by performing a Ground Balance, whereby
this mineralised response is effectively nulled out until you get no
response from the ground.
This sets the detector up to be able to detect responses from targets that
are either side of the ground balance point (i.e. rising or falling pitch
target responses).
When you ground balance the QED, you listen for the response when
you lower the coil to the ground, if it’s a rising (high) pitch (in other words
a short time constant response) you lower the MGB towards the GB
NULL point (and vice versa if the response is a falling (low) pitch) until
you get no response from the ground in either direction. The QED is then
said to be “ground balanced” (i.e. the ground is NULLED).
When the QED is ground balanced, targets with a short time constant
(small targets) will then produce a rising (high) pitch target response and
long-time constant targets (large targets - roughly 2.5 g or larger) will
produce a falling (low) pitch response, this equates to either side of the
ground balance point.
Now back to THS-B. In the very early QED development days, Howard
found that temperature changes caused the GB NULL point to drift, so
introduced an adjustment to compensate for this drift. This adjustment in
those early days was called “NULL”.
Further experimentation with this adjustment, Howard found that by
adjusting “UNDER NULL” resulted in enhanced target response to short
time constant (small) targets, and “ABOVE NULL” resulted in enhanced
target response to long time constant (large) targets.
The further either under or over NULL, the greater the enhancement,
until you could go no further either way as a result of the noise being
introduced.
Howard was on to something unique, and as a result the THS-B
adjustment was born as a user adjustable setting.
When the QED was first released this adjustment was called “BIAS”,
because you were able to bias the QED from NULL for better (enhanced)
target response for either small or large targets or adjust to NULL for
standard responses to small or larger targets.
In later releases this feature was renamed to THS-B, with the “B”
meaning “BIAS”.

18
2. THRESHOLD B –(THS-B) (BIAS)
Setting range 1-99
Factory preset at 50
Description
A small target will produce a rising pitch signal and a large target will
produce a falling pitch signal.
THS-B can be used to provide selective ("BIASED") enhancement for
either small (rising pitch) or large (falling pitch) targets.
THS-B (Bias) is used to set a ‘hair trigger’, such that less signal
strength is needed to produce a good audible signal.
Note: THS-A (All) does the same thing but affects both large and small (falling
& rising pitch) targets equally.
Lowering THRESHOLD B will accentuate rising pitch targets
(generally a small target).
•When prospecting for fine gold, fit a small coil and adjust
THRESHOLD B accordingly to suit the coil using a known
specimen target.
Raising THRESHOLD B will accentuate falling pitch targets (usually
large targets).
•When prospecting for larger specimens fit your selected coil and
adjust THRESHOLD B to suit your selected coil.
Note: BIAS can change slightly overtime depending on temperature.
Note: When the detector is Ground Balanced the audio volume will be very low.
Navigating to Threshold B
Select Menu Option #2, then press the button to open the
Threshold B setting.
Threshold Definition
Threshold is the
audible audio floor
that is set just above
‘silent’, so that the
operator can hear a
threshold just above
the prevailing
external conditions
(wind noise, ground
conditions, etc)
[Cite your source here.]

19
2. THRESHOLD B –(THS-B) (BIAS)
Setting range 1-99
Factory preset at 50
YouTube Reference
Click on this YouTube link to see how to set Threshold B.
Threshold B NULL Position
When looking for both rising and falling pitch targets it's best to put
THRESHOLD B in the NULL position (around 50) and raise
THRESHOLD A to create your desired threshold level.
Locating the “NULL Position” is determined by raising and lowering
Threshold B and taking note of the numbers as per the following
procedure:
•Start by raising THRESHOLD B with the button until the
THRESHOLD B starts to get to a tolerable volume level (e.g.
58).
•Then lower THRESHOLD B with the button until you get
the same volume level e.g. 44.
oThe above example range is 58 less 44 = 14.
oHalve the 14, which becomes 7.
oAdd 7 to 44 = 51.
51 is then the THRESHOLD B NULL position in this example.
YouTube Reference
Click on this YouTube link to see how to set Threshold B to NULL
Small Search Coils
When using small coils for small (tiny) targets, set the THS-B to an
acceptable audio level below the NULL position.
From the NULL position, decrease THRESHOLD B with the
button until an acceptable threshold volume is created (i.e. not too
noisy)
This will boost target responses for smaller targets in the ground.
Process:
•If a small coil is fitted, test the THS-B out with a small target.
•Swinging the coil over it will produce a rising pitch response.
•Lower the THS-B by one count at a time and note the
improvement in detection distance.
•Keep lowering THS-B until the background audio is at an
acceptable level.
Note: If THS-A is high then just a change of 1 or 2 on the BIAS will make the
QED too sensitive/unstable.
Tip:
Use a test target of say
0.2g. If the 0.2g is louder
and more noticeable
after lowering THS-B,
then BIAS has been
achieved for better
detection on smaller
targets
Tip:
When searching for
small targets: use a
small coil, a volume of
~30 or less, a gain of ~4,
with the THS-B set
below NULL until a
slight threshold is
created.

20
2. THRESHOLD B –(THS-B) (BIAS)
Setting range 1-99
Factory preset at 50
Medium Search Coils
Once the NULL position has been located, leave THRESHOLD B at the
NULL position to achieve a good even target response on both smaller
and larger targets in the ground.
Raise THS-A (Menu Item #3) to create desired audio threshold volume.
Large Search Coils
Once the NULL position has been located, increase THRESHOLD B
with the button until the desired threshold volume is created.
This will boost target responses for larger targets in the ground.
Notes
Tip:
Use test target of approx.
0.2g. If the 0.2g is faint or
undetectable, then BIAS
has been achieved for
better detection on larger
targets.