TDS784

Tektronix TDS784

1 GHz, 4 GS/s 4-channel digital scope

Produced from 1995 to (?)

Manuals

TDS784A (1995–1998)

TDS784C (1998–?)

TDS784D

(All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix TDS784 is a 1 GHz, 4 GS/s quad-channel digital storage scope.

There are four variants, all with the same specs but different hardware/software loads − TDS784A, B, C & D. Of these, the C and D models are the least problematic and most sought-after.

Key Specifications

Bandwidth	1 GHz at 10 mv/div and above; 750 MHz @ 5 mV/div; 600 MHz @ 2 mV/div; 500 MHz @ 1 mV/div
Sample rate	1 channel @ 4 GS/s, 2 channels @ 2 GS/s, 3 or 4 channels @ 1 GS/s
Resolution	8 bit
Record length	50k samples per channel (500k with option 1M)
Acquisition modes	sample, envelope, average, high-resolution, peak-detect
Display	Color; Zoom
Trigger modes	Edge, logic, pulse; Video trigger with option 05 (NTSC, SECAM, PAL, HDTV, and FlexFormat)
Storage	1.44 Mbyte, 3.5 inch, DOS 3.3-or-later floppy disk. NVRAM storage for saving waveforms, hardcopies, and setups. Units with option HD present (requires additional hardware) have a hard disk drive
I/O	Full GPIB programmability
Hardcopy	Using GPIB, RS-232, or Centronics ports

Software

Firmware

Options

05 - Video Trigger - Oscilloscope comes with tools that allow investigation of a range of NTSC, PAL, SECAM, and high definition TV signals.
1M - 4M acquisition length - Extends standard acquisition length from 50,000 points per channel to 130,000 samples on three or four channels, 250,000 samples on two channels, and 500,000 samples on one channel.
13 - RS-232C and Centronics hardcopy interfaces - Add RS-232-C and Centronics interface ports.
1F - Floppy disk drive - Add 3.5 inch, 1.44 MByte floppy disc drive.
2F - Advanced DSP math - Add advanced DSP math features such as FFT, integration, and differentiation.
2C - Communication Signal Analyzer - Oscilloscope comes configured for communications signal triggering and mask testing.
3C - P6701B with system calibration - Oscilloscope comes with a P6701B and calibrated short-wavelength optical reference receiver on channel 1.
4C - P6703B with system calibration - Oscilloscope comes with a P6703B and calibrated long-wavelength optical reference receiver on channel 1.
2M - 8M acquisition length - TDS 520D, 724D: To 2M samples on two channels and 4M on one channel. TDS 540D, 580D, 714L, 754D, 784D, 794D: To 2M samples on three or four channels, 4M on two channels, and 8M samples on one channel (Option includes a hard disk and is only available for the models listed above.)

Links

Internals

For units with serial numbers prior to B04xxxx, the latest known firmware revision is 6.6e. For units with serial numbers B04xxxx and above, the last known version is 7.4e. Note that, due to differences in acquisition and CPU board hardware, release 7.4e will not work in the earlier revision units. Early revision units may have a CPU board P/N of 679-4172-00. The later revision is 679-4349-00.

It is also worth noting the TDS754 and TDS784 series are nearly identical, with the differences being in front-panel cosmetics and the presence (754) or absence (784) of a few capacitors on the acquisition board. The only other difference is the position of instrument ID jumpers, also on the acquisition board. In fact, it is entirely possible to convert a 754 to a 784 (see the 'Links' section).

Note that any kind of firmware updating of the 784 (and most other similar TDS scopes) requires very specific equipment, starting with an older computer (ISA slots required) running MS-DOS 5.x or later as well as Windows 98SE. To interface with the scope, you will need a National Instruments PC/GPIB-II ISA-based (8-bit) GPIB board or a National Instruments AT-GPIB (16-bit) board and appropriate drivers. The software required to do the update (Tektool or Tekfwtool) also runs under DOS (or a DOS box in Windows 98). Information on this tool can be found in the Links section in the thread describing firmware updates.

Actual calibration requires the above computer, the specific PC/GPIB-II card and drivers and an MS-DOS environment. You will also need an Analogic/Data Precision model 8200 DC voltage standard and a levelled sine-wave generator capable of going up to 1 GHz (if you're just doing a 754, you can get away with a 500 MHz top end). Naturally, Tek used the SG503 and SG504.

The reason for the specific model of voltage standard is because that's the model Tektronix wrote the calibration software for. During the calibration process, it issues automated commands specific to the Analogic.

Note that in the TDS700D series, the acquisition board variant is important — the CPU Board with Firmware 7.xx cannot be used together with the old acquisition board, and the CPU board with old Firmware 6.xx doesn't run with the new acquisition board. The fact that the CPU board has part number 671-4349-00 is by itself not a reliable indication of a compatible firmware version.

Finally, for those with a dimming CRT, Simmconn Labs has developed a color LCD panel kit to replace said CRT in most of the TDS series which use them.

Pictures