109: Difference between revisions
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The 109's operating principle is that of a | The 109's operating principle is that of a | ||
[http://en.wikipedia.org/wiki/Pulse_forming_network#Transmission_line_PFNs charged transmission line pulse generator] | [http://en.wikipedia.org/wiki/Pulse_forming_network#Transmission_line_PFNs charged transmission line pulse generator] | ||
with a mechanical reed switch and external 50 Ω | with a mechanical reed switch and external 50 Ω transmission line/lines attached through two GR-874 50 Ω connectors. | ||
The length of the external cables determines the impulse width. | The length of the external cables determines the impulse width. | ||
Using two transmission lines of non-equal length, alternating pulses having different width can be produced. | Using two transmission lines of non-equal length, alternating pulses having different width can be produced. | ||
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File:109_right.jpg | Right internal | File:109_right.jpg | Right internal | ||
File:109_left.jpg | Left internal | File:109_left.jpg | Left internal | ||
File:109_back.jpg | Rear view | File:109_back.jpg | Rear view (connector not original) | ||
File:109_impulse.jpg | flying spot caught with 7904, S6, 7T11, 7M11. 2.5 V<sub>pk</sub>, T<sub>r</sub>=240 ps | File:109_impulse.jpg | flying spot caught with 7904, S6, 7T11, 7M11. 2.5 V<sub>pk</sub>, T<sub>r</sub>=240 ps | ||
File:Tek 109 schematic.png | schematic | File:Tek 109 schematic.png | schematic | ||
Revision as of 23:18, 17 September 2015
The Tektronix Type 109 is a pulse generator introduced in 1962. It uses a GR-874 50 Ω output connector and has a specified rise time of 250 ps.
Key Specifications
| Rise time | 250 ps |
|---|---|
| Pulse frequency | 550 to 720 Hz |
| Pulse length | 0.5 ns to 100 ns with a single charge line between the two charge line connectors, or up to 300 ns at half pulse rate with one open-ended charge line (other connector grounded) |
| Pulse amplitude | Internal supply: 0 to 50 V variable in three ranges (0.5 V, 5 V, 50 V), positive or negative, or external up to ± 300 V |
Manuals
Internals
The 109's operating principle is that of a charged transmission line pulse generator with a mechanical reed switch and external 50 Ω transmission line/lines attached through two GR-874 50 Ω connectors. The length of the external cables determines the impulse width. Using two transmission lines of non-equal length, alternating pulses having different width can be produced. Alternatively, an R-C network can be used to create pulses with R-C decay characteristic but longer duration.
The pulse-generating switch in the 109 is a mechanical mercury switch, which limits pulse frequency to about 600 Hz. Moreover, this switch has a relatively short life time (200 hours) — if the operator forgets to shut the 109 down over the weekend and some holidays, the reed switch will need replacement.
The internal voltage source is adjustable from 0 to 50 V in three ranges (0.5 V, 5 V, 50 V), either positive or negative. Using external voltage sources, pulses up to 300 V of either polarity are possible, including alternating positive/negative pulses.
Repair issues
Be aware during servicing that the thermal breaker is on full mains and has no protection cover!
Links
- Jim Williams, Linear Technology Application Note 120, "1 ppm Settling Time Measurement for a Monolithic 18-Bit DAC" - see Appendix H (p.30)
- Report comparing RG-58 with RG-174 using Tek 109 and Tek 661 (PDF)
- Tek 109 page @ amplifier.cd
Pictures
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Front view
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Right internal
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Left internal
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Rear view (connector not original)
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flying spot caught with 7904, S6, 7T11, 7M11. 2.5 Vpk, Tr=240 ps
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schematic
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017-067 Charge network for 109
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017-067 Charge network for 109 (description)
