Tag: Tektronix Oscilloscope
Tektronix 7854 Waveform Keyboard Rebuild
From the Tek Wiki:
The Tektronix 7854 Waveform Processing Oscilloscope, introduced in 1980, is a 400 MHz combined analog / digital mainframe in the 7000 series that takes two vertical and two horizontal 7000-series plug-ins. In addition to a conventional analog (real time) scope, it contains an equivalent-time sampling 10-bit digitizer and a programmable waveform processor with GPIB interface. The waveform processor can be programmed using a detachable calculator-style keyboard, using postfix operators (“reverse Polish notation” like HP calculators) that operate on entire waveforms, not just individual numbers.
Tek 7854 Mainframe #2 after cleaning
It is to the repair of the detachable keyboard that this post is devoted. I purchased a keyboard for a reasonable price only to find that some keys were intermittent, and some did not work at all.
Opening up the keyboard showed that it was filled with debris:
The … Read More »
Tektronix 556 Dual Beam Oscilloscope Testing: Vertical Bandwidth
I have been doing some basic testing of my Tektronix 556 Dual Beam Oscilloscope, and I have documented some parts of this process. I have also captured images of the traces, which I will share here.
Test Setup: Tektronix 556, 1A2 plug-in, Timebase A, Tektronix SG 503 Generator, and Tektronix TG 501 Time Mark Generator
I found the -3db vertical bandwidth of the 1a2/556 to be 65 Mhz, which is to be expected for the 50 Mhz rated 1A2.
TM 500 Module with Plug ins
50 kHz Reference Signal 6v peak to peak
5 MHz Sine Wave 6v peak to peak
20 MHz Sine Wave 6v peak to peak
40 MHz Sine Wave 4.8v peak to peak
50 MHz Sine Wave 4.3v peak to peak
65 MHz Sine Wave 4.2v peak to peak
I will continue this testing by investigating the absolute maximum trigger … Read More »
Tektronix 556 Dual Beam Oscilloscope Images
What follows is a series of images of my Tektronix 556 Dual Beam Oscilloscope displaying various waveforms. I am learning about this scope and how to use it.
A brief description of the unit can be found here: Tektronix 556
Thanks for reading.
Tektronix 556 Dual Beam Oscilloscope
I had recently the unique opportunity to acquire a complete Tektronix 556 Oscilloscope setup. This comprised the oscilloscope itself, the matching scope cart, original manual, probes and 12 plug-in units. This in itself is rare enough, but in addition, this particular scope has the optically desirable blue phosphor CRT and Tektronix C-27 Camera Bezel. This 50 MHz bandwidth oscilloscope was the state of the art when it was introduced in the mid 1960’s: Tekwiki Tek 556
This will be the first of many posts and updates as I work my way through checking and restoring this beautiful scope.
And now some images:
Tektronix Oscilloscopes 7904, 2467B, 2465B at 1GHz
The images to follow show a 1 GHz sine wave (amplitude not changed during the testing) on the following Tektronix oscilloscopes:
Tektronix 7904 with 7A24 vertical (400 MHz) and 7B92A horizontal
Tektronix 2467B (400 MHz scope)
Tektronix 2465B (400 MHz scope)
I have checked the bandwidth of the both the 2465B and 2467B used here, and they meet the 400MHz requirement at -3db (using a Tektronix SG504 with leveling head). The bandwidth of the 7904 mainframe + 7A24 vertical plug-in used in this test is about 450 MHz (-3db), but it remains at almost that level out to > 600 MHz. At 1 GHz I can still easily get 175 mV of signal on the screen of the 7904 + 7A24 where the two newer scopes can only manage 25 mV or less.