My Electronic Test Equipment

Doing electronic stuff needs some basic test equipment. A multimeter is a must, and an oscilloscope can't be beaten in versatility. But during the years I've collected plenty of other instrumentation as well. Most of this equipment has been purchased used. Some have been obtained for free, being either entirely broken or somehow malfunctioning or damaged. Some have required only cosmetic work, whereas others have needed up to 50 euros worth of parts to repair (that's still not a bad price for a spectrum analyzer). Some were ok or even brand new, but were greatly improved by minor custom modifications. The HPIB (a.k.a. GPIB or IEEE-488) enabled instruments can be remote controlled by a junk-pile PC fitted with a Keithley KPCI-488 Interface Card that was also picked up from a junk pile. Curse modern PCs that no longer have the "legacy" PCI bus... I don't want to pay Big Bucks for a %@\&&$^ing PCIe or USB host adapter that would enable me to lose the otherwise useless junk-pile PC...

My DIY electronics workbench
  • The desk was bought used and has been with me over 20 years. It is a bit worn, but sturdy as hell.
  • I added shelves to it to house all my test equipment. Threaded rods carry all the weight and allow easy adjustment as well.
  • With a good fluorescent light and an ESD mat, it's a good place to tinker. The shelves also are plenty sturdy.
  • Yet it was dirt cheap compared to a real Treston or similar workbench!
Hewlett Packard HP 54501A Digitizing Oscilloscope
  • Obtained free, "broken"
  • 100 MHz bandwidth, 4 channels
  • 10 Msps sample rate—higher frequency signals must be repetitive
  • HPIB bus
  • Huge range of automatic measurements, but no Tetris????? (The HP 54600 series does have Tetris. Damn.)
  • Repairs done: Replaced dead battery-backup RAM and performed self-calibration routines.
  • Total cost: 20 eur!
Iwatsu SS-6122 Analog Oscilloscope
  • 100 MHz bandwidth, 4 channels, triggers reliably to over 170 MHz (but does become impossible around 190 MHz).
  • Dual timebase, dual trace, impressively low jitter!
  • Cursor readout, frequency counter, everything except Tetris. (Again! Damn!)
  • An absolutely fantastic instrument!!!
  • A digital oscilloscope, with all its advantages and convenience, can only complement an analog one. It could never replace a top-notch analog scope like this one. (Just compare the number of buttons and knobs with the above digital scope!)
  • If you have the Service Manual, please let me know! (Though hopefully I will never need it.)
Hewlett Packard HP 8562B Spectrum Analyzer
  • Salvaged from junk pile
  • Swept-frequency triple-superheterodyne architecture
  • Frequency range originally 1 kHz–22 GHz in five bands, now only to 2.9 GHz
  • Option for external mixer
  • Resolution bandwidth 1 MHz to 100 Hz
  • HPIB bus
  • Repairs done: Replaced broken front-end mixer with a Mini-Circuits ZX05-U742MH-S+. Currently only low-band (up to 2.9 GHz) works. Replaced missing rotary control knob with one from an old Nokia monitor.
  • Total cost: 50 eur! I've seen an identical instrument (though fully working) going for 6500 eur!
  • I need to build a tracking generator for this
Boonton 42B Analog RF Microwattmeter
  • With 41-4A detector
  • Frequency range 200 kHz–7 GHz
  • Power ranges –50 dBm...+10 dBm full-scale
  • Really nice Ye olde scientific instrument. Gotta love the pale-green Boonton front face!
Anadex CP-700 Frequency Counter
  • Frequency ranges 5 Hz–100 MHz, 0.1–1.0 GHz
  • 100 / 10 / 1 Hz resolution
  • "Avionics test equipment", according to the sticker   :)
Awful head (manufacturer unknown)
  • Very, very awful, yes.
  • Extremely high quality
  • f(3dB) from 1.72 to 3.14 MHz, overrange from below 1 MHz to almost 4 MHz
  • Repairs done: Cleaning and basic calibration
  • I need to install an HPIB interface and a flappy tongue
MFJ 259B HF/VHF SWR Analyzer
  • Frequency ranges: 1.8–4, 4–10, 10–27, 27–70, 70–114, 114–170 MHz
  • Output level: Approx. +9 dBm on all ranges
  • Yes, it really is great for tuning antennas
  • With a loop of wire, it works as a dip meter (for tuning traps etc.)
  • Repairs done: Reattached dislocated analog meter, added rubber protector ring around power switch to avoid inadvertent switching on
RigExpert AA-1000 Antenna Analyzer
  • Frequency range from 100 kHz to 1 GHz
  • Extended frequency range with PC software
  • Numerical and graphical display of SWR or resistance and reactance
  • Smith Chart display, FFT TDR function, everything except Tetris
  • Runs on three AA-batteries (opposed to ten AAs in the MFJ 259B) with excellent battery life
  • Here's some notes about this fine instrument
  • How to update the firmware under Linux, and Why RXTX-Tuote sucks
  • Repairs done: Updated the firmware, glued some open-cell foam inside the battery compartment lid
Leader LSG-216 Standard Signal Generator
  • Obtained cheap, malfunctioning
  • Frequency ranges 0.1–30 MHz, 75–115 MHz
  • Output level –10...+99 dBuV
  • CW, AM and FM modulation
  • Internal (400/1000 Hz) or external modulation source, pilot/stereo/L/R/main/sub channels on FM
  • Repairs done: Replaced malfunctioning relays in output attenuator
Agilent E4421B ESG-A series Signal Generator
  • Frequency range 250 kHz–3 GHz (underrange down to 100 kHz)
  • FM, phase, AM and pulse modulation
  • Internal generator for modulation signal; also doubles as AF function generator
  • HPIB bus
  • I think this is the closest I can get to an RF amplitude reference, and at least the Boonton agrees with it to a fraction of a dB.
Advance Instruments J3 Signal Generator
  • Frequency range 10 Hz–100 kHz
  • Sine and square wave outputs
  • Isolated sine output
  • Nice gear-reduction frequency dial, Ye olde all-analog design, way cool...
Good Will Instruments GFG-8016D Function Generator
  • Obtained cheap, chassis made of duct tape
  • Triangle, square and sine wave outputs
  • Frequency range 0.2 Hz–2 MHz
  • Amplitude 0–10 Vpp, offset +/– 5 V to 50 ohms
  • Digital frequency counter
  • Repairs done: Rebuilt broken chassis
HP 8904A (Opt. 001) Multifunction Synthesizer
  • Sine output from DC to 600 kHz, other waveforms to 50 kHz
  • Triangle, square, ramp, sine, noise, and DC signals on four internal channels
  • Summation of internal channels to output; FM, AM, phase, DSB and pulse modulation of output using internal channels; simultaneous modulation using multiple internal channels; modulation by summed signal of multiple internal channels; omg this is so confusing...
  • Tone / DTMF / digital sequences
  • Single-ended (ground referenced) or dual-ended (floating) output
  • HPIB bus
Agilent HP 6632B System DC Power Supply
  • Voltage range 0–20 V
  • Adjustable current limit 0–5 A
  • Programmable overvoltage and overcurrent protection
  • HPIB bus
  • Repairs done: Custom front panel output modification
Manson EP-613 DC Power Supply
  • Voltage range 0–30 V
  • Adjustable current limit 0–2.5 A
  • Fixed 5 V and 12 V outputs at 500 mA
  • Probably the exact same device is also sold as Lion EP-613, DCSS EP-613 and Rapid PS3025
  • Repairs done: Custom modified with multi-turn potentiometers for more precise voltage and current adjustment
Fluke 8000A Digital Multimeter
  • Obtained cheap, "unknown condition"
  • 3 1/2 digit display
  • A reliable no-frills workhorse
  • Repairs done: Replaced amp-range fuse, checked calibration
Keithley 179 TRMS Digital Multimeter
  • Obtained cheap, "seems to work"
  • 4 1/2 digit display
  • True-RMS measurement
  • Same input connector is used for both voltage and current ranges—stupid!   :(
  • Repairs done: Calibration
Hewlett Packard HP 34401A Digital Multimeter
  • 6 1/2 digit display
  • Autoranging
  • True-RMS measurement
  • 4-wire resistance or voltage ratio measurement
  • Selectable front and rear connectors
  • HPIB bus
Lübcke Vario R52-260-T Variac
  • Salvaged from junk pile, perhaps unused???
  • Output voltage range: 0–260 V (for 230 V input)
  • Current rating: 2.5 A
  • Does not provide isolation   :(
  • Repairs done: Installed the naked variac in a new chassis (old PC power supply), with appropriate connectors and fuses
Muuntosähkö KL-1000T, Muuntosähkö KLM-200
Isolation Transformers
  • Rated at 1 kVA and 200 VA, respectively
  • Repairs done: Rebuilt chassis on 1 kVA unit, installed on/off switches on both units
Efratom/Datum LPRO-101, Trimble Thunderbolt Frequency standards
  • Rubidium atomic clock, 10 MHz frequency
  • GPS time standard (OEM model), 10 MHz frequency, PPS and data out
  • Repairs done: Installed both modules in a single chassis, built regulated power supplies for both.
  • I need to build a status display and PC interface for these, and eventually a distribution amplifier.
  • With a huge LED display, this might also become my radio station's UTC-clock.
Kenwood DP-71 Logic Probe
  • TTL / CMOS voltage ranges
  • Pulse detect function
  • Surprisingly useful for detecting transient signals that the oscilloscope can't see!
USBee AX PRO logic analyzer
  • Like the above logic probe, just more channels (eight) and a USB interface
  • Works with sigrok
  • Repairs done: Exchanged the 74HC245 chip with a 74LCX245, which is 5V-tolerant
  • The furry cow is not an original accessory
MBS-9 Stereo Microscope
  • Manufactured by LZOS (not Lomo, which is a common misconception)
  • 4.8×, 8×, 16×, 32× and 56× magnifications with the standard 8× eyepieces
  • Repairs done: Homebrew LED illumination with a 3 W LED, antistatic mat over the microscope's base
Weller WD-1000T Digital Soldering Station
  • WD-1 power unit
  • WSP-81 (a.k.a. WP80) 80 W soldering pencil
  • WDH 10T "Stop&Go" safety stand
  • An assortment of LT tips
  • This replaced my old Xytronic 369 which also was excellent
With these I have even soldered the occasional 0402 SMD component (inside my UV-3R radio). Though for convenience, I prefer to design my own circuits with 1206 or through-hole components. I have also considered making a reflow oven, but haven't got one yet. Really I don't have room for one either. With a wider tip, the 80 Watt soldering station is powerful enough to solder wires onto NiMH cells pretty much instantly, without overheating the cells.
Handicraft nuts—A better "helping hand"
  • An idea I once picked up in the Finnish Radioamatööri magazine—unfortunately I don't remember the author
  • Ordinary hex nuts—large ones—are much better than the ubiquitous "helping hand"
  • And cheaper!
PIC programmers
  • One usbpicprog device
  • One PICkit2 from Microchip
  • One PICkit3 from Microchip, which apparently is a debugger also
They all work, as did the JDM programmer I started with. Here's some notes on them. I also wrote a command line thing for the PICkit3 under Linux, using the Microchip mdb.sh utility.

What's still missing? A vector network analyzer would be nice (though I don't know what I'd do with it; play with it, I suppose). Perhaps a digital scope with a higher sample rate. A pulse generator. Maybe one more power supply with dual adjustable outputs. And a cesium atomic clock would be cool. Got any extra ones you don't want?

Antti J. Niskanen <uuki@iki.fi>