109

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.

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, maximum allowed is 50 ns.

The internal voltage source is adjustable from 0 to 50 V. Using an external voltage source, pulses up to 300 V are possible.

The special feature of the 109 is that the switching action is made directly by a mercury switch. The pulse frequency was therefore low (about 600 Hz) and life time was fairly short (200 hours). So, if the operator forgets to shut the 109 down over the weekend and some holidays, the reed switch will need replacement.

Repair issues

Be aware during servicing that the thermal breaker is on full mains and has no protection cover!

Manuals

• Tektronix 109 Manual (PDF)
• Report comparing RG-58 with RG-174 using Tek 109 and Tek 661 (PDF)

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 V_pk, T_r=240 ps

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  schematic