Category: Audio
Tektronix SG5010 Audio Signal Generator Repair
14th December
Background
The Tektronix SG5010 is an audio signal generator plug-in for the TM5000 modular test equipment system. It can generate five waveforms: sine wave, square wave, SMPTE/DIN intermodulation test signal, CCIF intermodulation test signal, and sine wave burst. All these signals may be swept in frequency and amplitude. It can generate very low distortion (THD+N < 0.0008%; my own measurements) sine waves from 20Hz-20kHz. It is CPU controlled with selections made via GPIB or front panel keyboard. These characteristics made it very desirable as part of an audio amplifier test lab. These units command a high price: Several working units have recently (Dec 2023) been sold for $USD 1500.
I recently acquired a non-working SG5010 for a good price. This post documents my efforts (ultimately successful) in getting it working.
Tektronix SG5010 Overview
Tektronix SG5010 Front Panel
First … Read More »
600 Ohm Terminator Build
27th December
When doing work on older audio gear it is sometimes necessary to maintain a 600 ohm impedance from, for example, a signal generator to a DUT or a piece of test gear. An easy way to do this is with a 600 ohm terminator. The article will document how I built such a terminator.
First I want to acknowledge the work of ElPaso TubeAmps (David Beard) who covered this very subject several years ago:
https://youtu.be/tIB3U-U29wg
50 ohm and 75 ohm BNC terminators are relatively easy to obtain, but 600 ohm terminators harder to come by. The solution is to build one as follows:
Obtain a suitable 50 or 75 ohm BNC terminator . You need the type which can be opened. One clue is that it may have flats on the end of the barrel which were used during assembly.The … Read More »