Test Gear
Introduction
There are a number of different pieces of test gear used for radio astronomy projects at HawkRAO.
These have been purchased from a number of sources, including eBay, ham radio disposal sales and retail outlets.
Antenna Analysers
There are a number of antenna analysers on hand.
RigExpert AA-30/AA-520/AA-1400:
Antenna analyzers designed for testing, checking, tuning or repairing antennas and antenna feedlines in 1 to 30 MHz, 520 MHz and 1400 MHz ranges respectively.
Sadly the AA-1400 stops right at 1400 MHz - missing the HI line frequency of 1420.4 MHz.
Spectrum and Vector Analysers and Signal Generators
GSP-730:
Covering 150 kHz to 3 GHz, the GSP-730 spectrum analyser is found to be useful for looking for RFI and checking filter passband curves. Conveniently the current spectrum displayed on the screen can be down-loaded to a USB drive directly in BMP format.
RF Explorer Handheld Spectrum Analyser
Covering from 240 - 960 MHz, this portable spectrum analyser was found to be useful for surveying the HawkRAO for RFI.
SMA Spectrum Analyser 138MHz - 4.4GHz
A NWT4000 clone, sold as a 138M-4.4G USB SMA signal source and simple spectrum analyser. The output is allegedly (i.e. - not checked at the time of writing) a tracking output which could be used to measure transfer characteristics of devices.
Software found after viewing:
Powered via a USB 2.0 B port connector.
NOTE: A capacitor must be used to block any DC being input to the SMA connectors or risk damaging the analyser.
MAX2870 LCD Signal Generator
Covers from 23.500 MHz to 6.000 GHz. Can be used a stationary frequency source ('Point') or as a sweep generator ('Sweep'). The reference clock is 25 MHz ('MCLK').Â
NanoVNA V2 (SAA2 SAAV2)
The NanoVNA (Vector Network Analyzer) is used for measuring and analysing the characteristics of radio frequency (RF) circuits up to 3 GHz.
Antenna analysis: measure the impedance and standing wave ratio (SWR) of antennas to optimise their performance.
RF filter analysis: Test and analyse the performance of RF filters, including bandpass, low-pass, and high-pass filters.
Cable testing: Test the quality and performance of RF cables, including checking for impedance mismatches and signal losses.
Frequency response analysis: Measure the frequency response of circuits, including amplifiers and filters, to determine their gain, bandwidth, and frequency response.
Comb Marker Generator - CMGEXT-SFSF
From High Sierra Microwave (no longer operating when checked March 2023).
This device generates harmonics of an input signal (1 to 300 MHz) up to an output of about 18 GHz (and beyond with ever-decreasing amplitude).
The accuracy of the GHz signals will be the same as the driving source.
Noise Sources
Broadband noise sources are useful for measuring the frequency response of amplifiers and filters. The left one of the two shown here has a lower level suitable for checking circuits with some amplification (e.g., LNA). The one on the right (bare PCB) has a higher level output suitable for testing standalone filters (i.e., no amplifier) such that the output level will drive some spectrum analysers.
