| The AIM 4170C antenna analyzer measures the
complex impedance (magnitude and phase) at each frequency of interest in the
range of 0.1 to 170 MHz. A PC is used to calculate all RF parameters,
including R +/-X, Magnitude and Phase, SWR, Return Loss, TL loss, and more
and plot the results in an easy to read graph and interactive Smith Chart. The test frequency is generated digitally and bandpass filters are used
to reject stray signals (like broadcast stations) that are more than a few
KHz from the operating frequency. A 12 bit analog to digital converter
digitizes the raw data. This avoids non-linearities associated with diode
detectors, and results in very good dynamic range and linearity for accurate
magnitude and phase measurements.
Impedance measurements can range up to 10K ohms. The true phase angle is
measured, so inductive or capacitive reactance can be determined without
ambiguity.
The RF generator can also be used as a signal source for testing
receivers. The frequency is very stable and it can be calibrated to WWV.
The digitized data is sent to the PC via the RS232 port. Power for the
analyzer can be obtained from a small DC power supply or a battery. With a
laptop computer, the unit is quite portable and it can even be mounted up on
a tower at the antenna feed point if desired, with power being supplied
through the RS232 cable.
The impedance at the antenna itself can be read with the AIM4170
located in the shack at the receiving/transmitting end of the coax. The
cable can be any length. The cable's impedance and loss
characteristics are determined by a simple calibration procedure and the
antenna's impedance is plotted directly during the scan.
High quality inside and out
There are no internal adjustments for calibration.
Calibrates easily yourself to NIST standards
The present model covers 0.1 MHz to 170 MHz.
Some of the RF parameters that are calculated include the following:
 | SWR referenced to any impedance |
| Resistance and reactance at the cable input |
| Resistance and reactance at the antenna terminals |
| Resistance and reactance of discrete components |
| Return loss |
| Reflection coefficient |
| Cable length |
| Cable impedance |
| Cable loss |
| Distance to fault (open or short) |
| Smith chart display |
| Quartz crystal parameters |
The scan data can be saved to disk or printed to compare before and after
results.
The program has been tested with Windows 95, 98, 2000, and XP. It does
not require an installation procedure. (It will run directly from a CD or a
floppy disk.)
Macintosh User's are also able to run the AIM -
Mac OS 10.x
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