TG501
The Tektronix TG501 is a time-mark generator plug-in for the TM500 system.
It was replaced by the TG501A in 1990.
Note the output must be terminated into 50 Ω or there may be no signal at all.
Key Specifications
| Interval | 1 ns to 5 s in 1−2−5 sequence |
|---|---|
| Timing accuracy | Stability 1×10-5, long-term drift 1×10-5 per month (with Option 1, 5×10-7 / 1×10-7 per month) |
| Error Readout | Accuracy 1 digit (±0.1% points), Range to ±7.5% |
| Amplitude | ≥1 V peak on 5 s through 10 ns; ≥750 mVp-p on 5 ns and 2 ns; ≥200 mVp-p on 1 ns (separate output) (all into 50 Ω) |
| Trigger Output | Slaved to marker output from 5 s through 100 ns. Remains at 100 ns for all faster markers |
| External Reference Input | 1 MHz, 5 MHz or 10 MHz; TTL compatible (internally hard wired so output frequencies counted down to 1 MHz) |
- Option 01 adds a 5 MHz tempature-compensated crystal oscillator (Y50), and a TTL decade counter (U50) for a stable, precise internal clock.
Links
- See the TG501/Repairs page for repair information.* TG501 Repair and Calibration by Zenwizard Studios @ YouTube
- TG501 In-Depth Troubleshooting of a Stubborn Unit by Zenwizard Studios @ YouTube
- TG501 In-Depth Troubleshooting of a Stubborn Unit Part 2 by Zenwizard Studios @ YouTube
Documents Referencing TG501
Patents that may apply to TG501
| Page | Title | Inventors | Filing date | Grant date | Links |
|---|---|---|---|---|---|
| Patent US 3562464A | Cam actuated switch having movable and fixed contacts on circuit board | Howard Vollum • Willem H Verhoef • Tony Sprando | 1968-10-07 | 1971-02-09 | Cam switches • 2101 • 2701 • 2703 • 432 • 434 • 465 • 475 • 5A15N • 5A18N • 5A20N • 5A21N • 5A38 • 5A45 • 5B10N • 5B12N • 7A15 • 7A16A • 7A18 • 7A19 • 7A24 • 7A26 • 7B10 • 7B15 • 7B50 • 7B51 • 7B52 • 7B53A • 7B50A • 7B70 • 7B71 • 7B80 • 7B85 • 7B87 • 7B92 • 7B92A • 7D01 • 7D12 • 7D15 • 7J20 • 7S12 • 7T11 • 7T11A • AF501 • AM502 • AM503 • DC502 • DC503 • DC504 • DC505 • DM501 • DM502 • FG501 • FG501A • FG502 • FG503 • FG504 • FG507 • PG501 • PG502 • PG505 • PG506 • PG506A • PG508 • TG501 • SC502 • SC503 • SC504 |
Rear Interface
| Connector Pin | Description | |
|---|---|---|
| Signal | Return | |
| 28A | 27A | Marker Out (requires front BNC disconnection) |
| 27B | 28B | Trigger Out (requires front BNC disconnection) |
| 25A | 26A | Internal 1 MHz Clock Out (TTL) |
| 24B | 25B | External Clock Input |
| 26B | 22B | Data Good (High when BCD data valid) |
| 17A..20A | 22B | bit 4..1 BCD Display data, MSD |
| 21A..24A | 22B | bit 4..1 BCD Display data, LSD |
| 16A | 22B | Fast=Low, Slow=High |
Internals
The TG501 internally produces a 1 MHz reference clock, either from an internal crystal oscillator, or from an externally supplied frequency.
A 100 MHz VCO is phase-locked to this reference frequency (in fixed-frequency mode) or to the output of a variable 1 MHz astable multivibrator (in variable frequency mode). When the variable oscillator is in use, its frequency is digitally compared to the fixed 1 MHz reference and displayed as a deviation in percent with a pair of LEDs indicating the sign (fast or slow).
A chain of dividers running off the 100 MHz clock provide the selectable output markers.
The 1 ns output uses a step recovery diode (HP 5082-8872, part 152-0503-00).
Prices
| Year | 1975 |
|---|---|
| Catalog Price | $745 |
| In 2023 Dollars | $4,300 |
Pictures
TG501
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TG501 early version
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TG501 late version
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TG501 early version
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TG501 early version
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TG501 output waveform
Parts
Some Parts Used in the TG501
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 152-0503-00 | 152-0503-00 | Discrete component | 500 ps step recovery diode | 1503C • TG501 • TG501A |
| Signetics N8T06B | 156-0379-00 | Monolithic integrated circuit | 7-segment driver | TG501 |