Not long ago, I started collecting some old EMC equipment so I could write EMC software at home. Since this was MY money and not funded in any way by my employer, I could not spend a lot of money. I found some good deals on eBay. The difficulty was in finding manuals for some of the instruments. When an instrument popped up on eBay that I was interested in, I would first try to find a source for the manual. Sometimes I could find one on eBay, other times I had to search several sources before I could find one. Once I had a source for a manual, then I would consider bidding on the instrument.Following is a list:
The following two instruments were phased out at a nearby business, so I picked them up for next to nothing.
New! LeCroy 9410 Digitizing Oscilloscope. 150MHz bandwidth. Nice unit, although I have not had much chance to play with it yet.
New! Wavetek 175 Arbitrary Waveform Generator. Again, I have not had much chance to play with this. I have wanted an arb generator for some EMC related projects I had in mind, so this should fill the bill.
Anritsu MS420B Network/Spectrum Analyzer. Nice instrument that covers 10Hz to 30MHz. Selectable input impedance, three outputs, two inputs. Does not do impedance measurements, though. It does do magnitude, phase and delay. I also picked up a low frequency E-field rod antenna with this. This one came will all the manuals.
Tektronix 495p Spectrum Analyzer. By far this is the most expensive piece of equipment I have purchased. It covers the frequency range from 100 Hz to 1.8 GHz. It also has the 75 ohm input option, which actually gives me both a 50 AND a 75 ohm input. (Some HP analyzers swap the 50 ohm input for a 75 so you have either one OR the other). I actually thought I was buying a 496p, but found out the unit was actually a 495p, which has more built-in marker functions and GPIB commands. It took a while to find manuals, but it was not until after I bought a manual set for the 496p that I found out that it was a 495p. Most of the internal circuitry is the same, the biggest difference seems to be the firmware. I had to buy a 495p programming manual so I could get all the programming commands.
Tektronix 2430A Digital Oscilloscope. Another major purchase. This unit has a 150 MHz repetitive signal bandwidth, but only about 40 MHz single-shot performance. It is fully programmable from the GPIB port, and can even be switched to a GPIB monitor mode which displays GPIB traffic on the screen!
Gigatronics 6061A Signal Generator. I got a really great deal on this. As I understand it, the Fluke signal generators were actually manufactured by Gigatronics. The manual I was able to find has Fluke and Gigatronics logos. It covers the range from 10 kHz to 1 GHz. This unit came with the rear connection option (which I really did not want) but has internal AM and FM modulation, with an internal 400 and 1000 Hz modulation source. Very easy front-panel operation and very straightforward GPIB commands.
HP 3314A Function Generator. Really old technology, but works well. Up to 20 MHz sine wave. Will do ramp, triangle, square etc at lower frequencies. Has external trigger and modulation capabilities, as well as programmable waveforms.
HP 66312A Power Supply. I did not really need a power supply, but had always wanted to get a good lab-grade DC supply. I picked this one up since it also is GPIB programmable. I has lots of measurement capability, including built-in data logging and max-min modes. Up to 20 volts, 2 amps.
Gigatronics 8541B Power Meter. Another great deal. Came with a 80401A power sensor. The sensor is not a true average sensor, but a diode sensor. It has a very wide dynamic range, from -67 to +20 dBm, with the square-law region below -20dBm. It seems to be very good down to about -60. The difference between this sensor and a true average sensor is when it comes to modulation. Since the upper end of the dynamic range is actually in the non-linear region, the firmware in the meter compensates and gives a corrected value. If the signal is AM modulated, you must tell the power meter the signal is modulated so it can give a corrected reading. All of this is not necessary with a true-average power sensor. BUT, a true-average power sensor usually does not have such a wide dynamic range, usually only 50dB or so.
HP 437B Power Meter. Bought this one from a guy in Finland! Actually got it cheaper than I could have if I had purchased it from someone in the US. Came with a 8482H power sensor.
HP3488 Switch Controller. This is a very versatile unit, with many plug-in board options. I found the empty 3488 going for less than $50, and could usually buy the 3488 with a couple of plug-in boards for less than $100. I have an almost complete set of boards now, everything from the general purpose switches to the 18 gHz coax switches.
HP 5328A Universal Counter. Cheap enough, so I got it. Rated up to 100 MHz, works up to 150. There are options for a higher frequency range, as well as a DC voltmeter, which mine does not have.
Keithley 197 Benchtop DMM with GPIB.
I have enough instrumentation now that I can write software for most EMC tests, though my main interest is in RF immunity. While I don't have any amplifiers, I don't really need one since I can simulate most immunity tests by connecting the signal source directly to the measuring instruments (except field probes). I do like to write software that is easily configurable, so I may be looking for more instruments in the future.