The Autek Antenna Analyser


Properties

Case: 4.5 x 2.5 x 1.5 inches, black ABS plastic

Weight: 7 ounces

Tuning range: 1.2 to 35 MHz

Display: LCD with 1/2 inch digits

Readings:

Power: 9 volt Alkaline battery (not included)

Description

The appearance of the instrument is deceptively simple. It has an SO-239 coaxial connector and a ground lug for connections on one end and a LCD display on operating controls on its face.

Operating controls are: pushbuttons for power on/selection of frequency band and mode and two knobs for tuning. It tunes over the hf band in several ranges and is tuned by means of coarse and tune controls.

Operating frequency is displayed on its multi- purpose LCD display. The display is also used to show measured values, depending on the mode chosen. Also included is an accessory kit consisting of a couple of mini crocodile clips, a banana plug and directions for use of the analyzer to measure rf components.

Use of an microcontroller chip allows the RF-1 to perform multiple functions and give unambiguous digital readings. Operating theory is not given in the instructions, but it appears to use a broadband bridge - probably resistive. Hints in the instructions mention also diode detectors and an A/D converter.

It appears that the device performs analogue rf measurements, rf detection and conversion to digital data, then calculation and display using the microcontroller.

SWR and rf impedance are calculated and displayed directly. Inductance and capacitance readings are calculated as if the measured impedance were pure reactance. Methods are described for using displayed values to determine the type of reactance present and estimating the resistive component of the impedance.

Its operation is similar to SWR analyzers made by MFJ, but it has the added advantage of calculating and displaying more that just frequency, SWR and "Resis tance." Not only that, but the digital display is much easier to read that the analog MFj meters. On the other hand the high end MFJ units have a jack to allow use of the internal frequency counter with external signals - a feature that the Autek device lacks. The RF Analyzer's battery life is not given, but is probably longer than its competitors because of its liquid crystal display. At 1/4 the size and weight, the RF-1 is far more usable that the MFJ units in outdoor or tower-top applications.

The very thorough instruction book covers a wide variety of uses including:

It also gives practical guidelines for usage and expected error values for its various operating modes along with methods to minimize measurement error. The book itself is a minicourse in rf and antenna measurement techniques.

Who should buy one? Well, the obvious first answer is the serious hf antenna experimenter or builder. The unit is inexpensive enough that even a casual "appliance operator" might like to have one to check his antenna periodically. Unlike ordinary SWR meters the RF-1 allows its users to determine the nature of antenna degradation if it occurs. Additionally, the serious ham builder can use the expanded measurement capabilities of the gadget for analysis and measurement of the bench. It isn't a lab-grade instrument, but then again, it doesn't cost 10,000. It can be very handy for checking rf components and resonant circuits as well as antenna, feedline and antenna coupler adjustment.

With thanks to Joe Everhart, N2CX, from whose review the above was taken.


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