Difference between revisions of "108"

From TekWiki
Jump to navigation Jump to search
Line 16: Line 16:
  
 
<gallery>
 
<gallery>
Image:Tek 108 front.jpg
+
Image:Tek 108 front.jpg|Front view
Image:Tek 108 left.jpg
+
Image:Tek 108 left.jpg|Left view, mercury switch
Image:Tek 108 right.jpg
+
Image:Tek 108 right.jpg|Right view, selenium recitifier
Image:Tek 108 output network.jpg|Output network
+
Image:Tek 108 output network.jpg|Output network, rear of N connector
Image:Tek 108 approx schem.png
+
Image:Tek 108 approx schem.png|Approximate schematic
 
</gallery>
 
</gallery>

Revision as of 10:06, 15 October 2011

The Tektronix 108 is a 1ns-risetime pulse generator. It is the predecessor of the more complex and faster 109. Repetition rate of the 108 is 240 pps and the maximum pulse amplitude is 10Vpk into 50 Ohm load. It uses a mercury switch and selenium rectifiers. The price in July 1959 was $125. The output is through an N connector.

Referring to the output network photo below, current flows in from the left through the 1K resistor, and charges the four red 0.1 uF capacitors that are in parallel. When the mercury switch (terminals visible at lower right) closes, the capacitors are suddenly connected to the output load of the pulse generator, causing a sharp step in the output voltage. The starting voltage of the step is typically 0V. The final voltage is adjustable, both in polarity and magnitude. The range is approximately -10V to 10V.