109: Difference between revisions

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The pulse-generating switch in the 109 is a mechanical [[mercury switch]], which limits pulse frequency to about 600 Hz.
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.  
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. [[Media:Component_news_259.pdf|Component News 259, 5 May 1978]] says:
<blockquote>
The most critical usage of mercury reed switches is in Tek's Type 109 Pulse Generator.
(The 109 is used in-house for calibrating virtually all our product lines.)
Unfortunately, there are no plans to replace this instrument line, which is dependent on the 260-0282-01 mercury reed switch
for a 250 ps rise time pulse capability.
To make matters worse, these switches are single-sourced from C. P. Clare, who must import them from Belgium.
We are also having problems obtaining quality parts.
(The raw switch costs approximately $5, but when the cost of rejects and added tooling are figured in , the cost per switch approaches $55.)
</blockquote>


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.   
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.