TDS784

Manuals – Specifications – Links – Pictures

The Tektronix TDS784 is a 1 GHz, 4 GS/s four-channel digital storage scope with a color screen.
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.

The TDS784 utilizes a specialized NuColor liquid crystal color shutter (LCCS) system, which is a hybrid technology combining a monochrome CRT with a liquid crystal color filter.

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
Deflection	1 mV/div to 10 V/div with calibrated fine adjustment
Resolution	8 bit
Timebase	200 ps/div to 10 s/div
Record length	Standard instrument: 50k samples per channel 1M Option: 500 K points on 1 channel; 250 k points on 2 channels ; 130 k points on 3 or 4 channels 2M Option: 8 M points on 1 channel; 4 M points on 2 channels ; 2 M points on 3 or 4 channels
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
Hardcopy	Using GPIB, RS-232, or Centronics ports

• TDS784 Options and Accessories

Software

• TDS700/700A Field Adjustment Software 063-2601-00 (ZIP)
• TDS700C Field Adjustment Software 063-2774-01 (ZIP)
• TDS700C/700D/714L V1.129 Field Adjustment Software (ZIP)
• TDS700C/700D/714L V1.129 Field Adjustment Software 063-3289-01 (ZIP)
• See also TDS Series Software

Firmware

• TDS784C v5.0e Firmware (ZIP)
• TDS784C v5.2e Firmware (ZIP)
• TDS784C v5.3e Firmware (ZIP)

• TDS784D v6.3e Firmware (ZIP)
• TDS784D v6.4e Firmware (ZIP)
• TDS784D v6.6e Firmware (ZIP)

• TDS784D v7.1.1e Firmware (ZIP)
• TDS784D v7.2e Firmware (ZIP)
• TDS784D v7.4e Firmware (ZIP)

Links

See the Repairs page regarding HDD/FDD replacements.

• EEVBlog Forum Threads:
  • EEVBlog Forum thread on TDS options and how to enable them
  • Firmware update via GPIB
  • Serial debug and console interface card for TDS500-700 series
  • Console port debug adapter for TDS500-700 series
• Youtube
  • NVRAM module replacement - Near Far Media
  • Input hybrid repair - Near Far Media
  • Power supply repair - Near Far Media

• Simmconn Labs LCD replacement kits for CRT-based TDS O-scopes
• Wavestar Product Key
• TDS error log viewer
• Enabling options via GPIB interface - ko4bb.com

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.
Using the 'Unified Tektool', a firmware update can be achieved using a standard USB-GPIB adapter as detailed in this link. Be sure to back up BOTH your firmware AND NVRAM before writing the new firmware in!
If the new firmware does not work in your scope, a full clear of the firmware and NVRAM and then loading your backed up firmware and NVRAM back in will have it working again on the original firmware.

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

• 

  Front View

• 

  Rear View without Opt. 13

• 

  Option 05 Internal Parts

• 

  Option HD Internal Parts, 2.5" Disk Version

• 

  Option HD Internal Parts, PCMCIA Disk Version

Components

Some Parts Used in the TDS784D