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A resistance decade box, sometimes called a resistance substitution box is used mainly for creating a known temporary resistance in an electronic circuit.

A decade box is nothing more than a series of precision, or if you prefer, extremely close tolerance resistors connected by switches in such a way that it is possible to select the resistance value you require.

The Rockseed RS305P programmable power supply is a single-output high-precision DC supply, microprocessor controlled with LED display of voltage, current and power at the same time.

Every electronics workbench should have at least a couple of power supplies available especially when testing out equipment. My radio equipment is run from a 50amp power supply, and I have a second 45amp supply for bench testing. I also use a Rockseed RS305P bench supply when working on equipment or projects where I need to limit either the voltage or current.

The MSA-4901 is a spectrum analyser designed to cover the 1 to 300MHz range. The oscilloscope is a time domain type in which the frequency domain and vertical axis are calibrated in logarithmic form.

Although this unit is not as complex as high-end laboratory grade instruments, it serves my purpose. It has to be mentioned that my Hantek DSO5102 digital oscilloscope has an FFT function which mathematically emulates a spectrum analyser.

The Schlumberger Solatron 7150plus is a compact bench/portable, mains-operated multimeter, similar to the popular HP/Agilent 34401A, which offers 5½ / 6½ digits resolution and an accuracy to 0.005%.

The meter is built in good quality 1980s technology using through-hole components on a motherboard, carrying power supply, processor, IEEE488 (HPIB, GPIB) interface and a display board, plus a galvanically isolated, separate analogue/floating logic board with its own processor controlling the A/D conversion and communicating serially with the base unit. The two boards are separated by an aluminium shield/chassis.

The Racal-Dana 9008 modulation meter allows easy and accurate measurement of modulation levels on RF signals.

There really isn’t much to say about a modulation meter, as it’s name describes what it does perfectly – Modulation meters measure degrees of modulation in a modulated signal.

To compliment the older analogue Tektronix oscilloscope, I have at my disposal a Hantek digital oscilloscope.

Although this instrument is a fairly low cost entry level digital scope, it performs perfectly well for my needs. The Hantek DSO5102B which is a dual channel 100 Mhz unit with 1 GS/a real time sampling rate and a more than adequate 1 MB memory depth (sample points) with a 7” LCD.