RigExpert AA-35 ZOOM User manual

AA-35 ZOOM RigExpert®
User’s manual
Antenna and cable
analyzer

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Introduction
Operating the AA-35 ZOOM
First time use
Main menu
Multifunctional keys
Connecting to your antenna
SWR chart
Chart ZOOM
Data screen
Frequency and range entry
R,X chart
Memory operation
SWR mode
Display all parameters
Applications
Antennas
Coaxial lines
Measurement of other elements
Annexes
Annex 1: Specifications
Annex 2: Precautions
Annex 3: Setup menu
Table of contents

User’s manual
Thank you for purchasing a RigExpert
AA-35 ZOOM Antenna and Cable Analyzer!
We did our best to make it powerful yet easy
to use.
The analyzer is designed for measuring SWR
(standing wave ratio), return loss, cable loss,
as well as other parameters of cable and
antenna systems in the range of 60 kHz to
35 MHz. A built-in ZOOM capability makes
graphical measurements especially effective.
The following tasks are easily accomplished
by using this analyzer:
• Rapid check-out of an antenna
• Tuning an antenna to resonance
• Comparing characteristics of an antenna
before and after specific event (rain,
hurricane, etc.)
• Making coaxial stubs or measuring their
parameters
• Measuring capacitance or inductance of
reactive loads 1. Antenna connector
2. Liquid crystal display
3. Keypad
4. USB connector
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Introduction
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RigExpert AA-35 ZOOM
Main menu
The Main menu acts as a starting point
from where different tasks may be
launched.
Use (Cursor up) and (Cursor
down) keys to scroll through the menu,
then press (OK) to select an item.
For your convenience, a battery
indicator is shown at the top-left corner
of the screen. This indicator is replaced
with a USB icon when the analyzer is
connected to your computer.
The analyzer will be turned off automatically if not in use for too long.
First time use
Please insert two AA batteries
(only alkaline or Ni-MH ones) into
the battery compartment of the
analyzer, watching the polarity.
Instead, you may power it from a spare USB port of your computer by using a
conventional USB cable.
Press the (Power) key located at the bottom-right corner of the keypad to turn
on the analyzer. After displaying the initial message (showing a firmware version and a
serial number of the instrument), a Main menu appears on the screen.
You may use hot keys for the quick access to certain tasks. For instance, press
the
(SWR chart) button to open the SWR chart screen immediately.
Do not use Li-ion or other batteries with voltage more than 1.5 V.
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Operating the
AA-35 ZOOM

User’s manual
Multifunctional keys
Most keys on the analyzer’s keypad perform
several functions.
For instance, numbers (1) are used to enter
frequency and other numerical parameters.
Main functions (2) provide quick access to most
common tasks. Alternative functions (3) are
executed if the user holds the (Functional)
key. For the convenience, alternative functions
are marked with yellow.
You may press the (Help) key to open a help screen listing all active hot keys.
Connecting to your antenna
Plug the cable to your analyzer’s antenna connector, and then tighten the rotating
sleeve. The rest of the connector, as well as the cable, should remain stationary.
If you twist other parts of the connector when tightening or loosening, damage may
easily occur. Twisting is not allowed by design of the UHF-connector.
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1
2
3

RigExpert AA-35 ZOOM
Chart ZOOM
Use the arrow keys to increase or decrease the center frequency or the scanning range.
Watch the chart zooming in or out, or changing its position. Use the (Functional
key) and (Cursor up) or (Cursor down) key combination to zoom the vertical
scale of the chart.
Do not forget to press the (OK) key for the new measurement to start.
SWR chart
Once your antenna is connected to
the analyzer, it is time to measure its
characteristics. Press the (SWR
chart) key to open the SWR chart screen,
then press (OK) to start a new
measurement.
A few moments later, the result will be
displayed on the analyzer’s screen.
Press the + key combination to
run a continuous sweep.
A small triangle at the bottom of the chart corresponds to a point at which the SWR
reaches its minimum.
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User’s manual
Data screen
The data screen is available in all chart
modes. Press the (Data) key to
display various parameters of a load at
cursor.
Frequency
and range entry
To enter the center frequency or the
sweep range, press the (Frequency,
Range) key.
Use cursor keys to navigate, or the
to keys to enter values. Do not forget
to press the (OK) key to apply.
Press (Up) or (Down) cursor keys while holding
the (Functional) key to quickly choose a radio amateur band.
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RigExpert AA-35 ZOOM
R,X chart
Press the (R,X chart) key in the Main
menu to access the R,X chart mode.
Positive values of reactance (X)
correspond to inductive load, while
negative values correspond to capacitive
load.
The chart will display Rand Xfor series
or parallel models of a load. Press
(Functional key) and to switch
between these models.
The marker at the bottom of the screen shows a resonant
frequency closest to the center of the scan.
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User’s manual
Memory operation
Press the (Save) key to save the
chart into one of 10 available memory
slots.
To retrieve your readings from the
memory, press then (Load) key,
select a memory slot number and press
(OK).
SWR mode
To watch the SWR at a single frequency,
press the (SWR) key.
Do not forget to press the (OK)
key to start or stop the measurement.
Change the frequency with (Left)
or (Right) cursor keys, or press
the (Frequency) key to enter a new
frequency.
The SWR icon in the top-left corner flashes
when the measurement is performed.
To rename any existing memory slot, press (Functional key)
and (Edit) key combination.
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RigExpert AA-35 ZOOM
Display all parameters
To display various parameters of a load
on a single screen, press the (All)
key.
Do not be confused by negative values of L or C. This can be useful for
experienced users.
This screen displays values for series as well as parallel models
of impedance of a load.
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• In the
series model, impedance is
expressed as resistance and reactance
connected in series:
• In the parallel model, impedance is
expressed as resistance and reactance
connected in parallel:
R
X
Z = R + jX R X
Z = R ||+ jX

User’s manual
Antennas
Checking the antenna
It is a good idea to check an antenna
before connecting it to the receiving or
transmitting equipment. The SWR chart
mode is good for this purpose.
The picture on the left shows the SWR
chart of a HF antenna. The operating
frequency is 14.3 MHz. The SWR at
this frequency is about 1.3, which is
acceptable.
The next screen shot shows SWR chart
of another antenna. The actual resonant
frequency is about 14.65 MHz, which is
too far from the desired one. The SWR at
14.3 MHz is 2.8, which is not acceptable
in most cases.
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Applications

RigExpert AA-35 ZOOM
Adjusting the antenna
When the measurement diagnoses that the antenna is off the desired frequency, the
analyzer can help in adjusting it. Physical dimensions of a simple antenna (such as a
dipole) can be adjusted knowing the actual resonant frequency and the desired one.
Other types of antennas may contain more than one element to adjust (including coils,
filters, etc.), so this method will not work. Instead, you may use the SWR mode, the
All parameters mode or the Smith chart mode to continuously see the results while
adjusting various parameters of the antenna.
Coaxial lines
Open- and short-circuited cables
The pictures on the right show R and
X charts for a piece of cable with
open- and short-circuited far end. A
resonant frequency is a point at which X
(reactance) equals to zero:
• In the open-circuited case, resonant
frequencies correspond to (left
to right) 1/4, 3/4, 5/4, etc. of the
wavelength in this cable;
• For the short-circuited cable, these
points are located at 1/2, 1, 3/2, etc.
of the wavelength.
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User’s manual
Cable length measurement
Resonant frequencies of a cable depend on its length as well as on the velocity factor.
A
velocity factor is a parameter which characterizes the slowdown of the speed of
the wave in the cable compared to vacuum. The speed of wave (or light) in vacuum is
known as the electromagnetic constant : c =299,792,458 meters (or 983,571,056 feet)
per second.
Each type of cable has different velocity factor: for instance, for RG-58 it is 0.66.
Notice that this parameter may vary depending on the manufacturing process and
materials the cable is made of.
To measure the physical length of a cable,
1. Locate a resonant frequency by using the R,X chart.
Example:
The 1/4-wave resonant frequency of a
piece of open-circuited RG-58 cable is
4100 kHz.
2. Knowing the electromagnetic
constant and the velocity factor of the
particular type of cable, find the speed of
electromagnetic wave in this cable.
299,792,458 × 0.66 =
197,863,022 meters per second
- or -
983,571,056
× 0.66 =
649,156,897 feet per second
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RigExpert AA-35 ZOOM
Velocity factor measurement
For a known resonant frequency and physical length of a cable, the actual value of the
velocity factor can be easily measured:
3. Calculate the physical length of the
cable by dividing the above speed by
the resonant frequency (in Hz) and
multiplying the result by the number
which corresponds to the location of this
resonant frequency (1/4, 1/2, 3/4, 1, 5/4,
etc.)
197,863,022 / 4,100,000 × (1/4) =
12.06 meters
- or -
649,156,897 / 4,100,000
× (1/4) =
39.58 feet
3. Finally, find the velocity factor .
Just divide the above speed by the
electromagnetic constant.
Example:
5 meters (16.4 feet) of open-circuited
cable. Resonant frequency is 9400 kHz
at the 1/4-wave point.
2. Calculate the speed of electromagnetic
wave in this cable. Divide the length
by 1/4, 1/2, 3/4, etc. (depending on the
location of the resonant frequency), then
multiply by the resonant frequency (in
Hz).
5 / (1/4) × 9,400,000 =
188,000,000 meters per second
- or -
16.4 / (1/4)
× 9,400,000 =
616,640,000 feet per second
1. Locate a resonant frequency as
described above.
188,000,000 / 299,792,458 = 0.63
- or -
616,640,000 / 983,571,056 = 0.63
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User’s manual
Cable fault location
To locate the position of a probable fault in a cable, just use the same method as when
measuring its length. Watch the behavior of the reactive component (X) near the zero
frequency:
• If the value of X is moving from –∞to 0, the cable is open-circuited:
• If the value of X is moving from 0 to +∞, the cable is short-circuited:
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RigExpert AA-35 ZOOM
Making 1/4-λ, 1/2-λ and other coaxial stubs
2. Cut a piece of cable slightly longer than
this value. Connect it to the analyzer. The
cable must be open-circuited at the far
end for 1/4-λ, 3/4-λ, etc. stubs, and
short-circuited for 1/2-λ, λ, 3/2-λ, etc.
ones.
A piece of 1.85 m (6.07 ft) was cut.
The margin is 10 cm (0.33 ft). The
cable is open-circuited at the far end.
3. Switch the analyzer to the All
parameters measurement mode. Set the
frequency the stub is designed for.
28,200 kHz was set.
4. Cut little pieces (1/10 to 1/5 of the
margin) from the far end of the cable
until the Xvalue falls to zero (or changes
its sign). Do not forget to restore the
open-circuit, if needed.
11 cm (0.36 ft) were cut off.
1. Calculate the physical length. Divide
the electromagnetic constant by the
required frequency (in Hz). Multiply the
result by the velocity factor of the cable,
then multiply by the desired ratio (in
respect to λ).
299,792,458 / 28,200,000 × 0.66 ×
(1/4) = 1.75 meters
- or -
983,571,056 / 28,200,000
× 0.66 ×
(1/4) = 5.75 feet
Pieces of cable of certain electrical
length are often used as components of
baluns (balancing units), transmission
line transformers or delay lines. To make
a stub of the predetermined electrical
length,
Example:
1/4-
λ stub for 28.2 MHz, cable is RG-
58 (velocity factor is 0.66)
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User’s manual
Measuring the characteristic impedance
The characteristic impedance is one of the main parameters of any coaxial cable.
Usually, its value is printed on the cable by the manufacturer. However, in certain cases
the exact value of the characteristic impedance is unknown or is in question.
To measure the characteristic impedance of a cable,
1. Connect a non-inductive resistor
to the far end of the cable. The exact
value of this resistor is not important.
However, it is recommended to use 50 to
100 Ohm resistors.
Example 1: 50-Ohm cable with 100
Ohm resistor at the far end.
Example 2: Unknown cable with 100
Ohm resistor at the far end.
2. Enter the R,X chart mode and make
measurement in a reasonably large
frequency range (for instance, 0 to 55
MHz).
Example 1:
50-Ohm cable
Example 2:
Unknown cable
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RigExpert AA-35 ZOOM
3. Changing the display range and
performing additional scans, find a
frequency where R(resistance) reaches
its maximum, and another frequency
with minimum. At these points, X
(reactance) will cross the zero line.
Example 1:
3.85 MHz – min., 8.25 MHz – max.
Example 2:
5.50 MHz – max., 2.75MHz – min.
4. Switch to the Data at cursor screen
by pressing the (Data) key and
find values of Rat previously found
frequencies.
Example 1:
28.4 Ohm – min., 88.4 Ohm – max.
Example 2:
90.0 Ohm – max, 61.3 Ohm – min.
5. Calculate the square root of the
product of these two values.
Example 1:
square root of (28.4 × 88.4) =
50.1 Ohm
Example 2:
square root of (90.0 × 61.3) =
74.3 Ohm
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User’s manual
Measurement of other elements
Although RigExpert AA-35 ZOOM is designed for use with antennas and antenna-
feeder paths, it may be successfully used to measure parameters of other RF elements.
Capacitors and inductors
The analyzer can measure capacitance from a few pF to about 0.1 μF as well as
inductance from a few nH to about 100 μH. Since measuring of capacitance and
inductance is not a main purpose of RigExpert analyzers, the user will have to gain
some experience in such measurements.
Be sure to place the capacitor or the inductor as close as possible to the RF connector
of the analyzer.
1. Enter the R,X chart mode and select a reasonably large scanning range. Perform a
scan.
Example 1:
Unknown capacitor
Example 2:
Unknown inductor
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