39,552
edits
(added links to documents explaining spoiler switch) |
No edit summary |
||
Line 4: | Line 4: | ||
==Pin-out== | ==Pin-out== | ||
{|border="0" | |||
|- valign="top" | |||
| width="350px" | | |||
{| class="wikitable" | {| class="wikitable" | ||
Line 55: | Line 58: | ||
| bgcolor="LightGreen" | Control Signals | | bgcolor="LightGreen" | Control Signals | ||
|} | |} | ||
| | |||
==Signal Input Impedance and Spoiler Switch Hole== | ==Signal Input Impedance and Spoiler Switch Hole== | ||
The input impedance of 500-series scopes presented to the plug-in at pins 1+3 is approximately kept constant by adding shunt capacitors at the input depending on the tube type used. Early, scopes like the [[536]] and the [[555]] use a [[12BY7]] differential amplifier in the input stage, and the plug-in is loaded with the grid input capacitance with 2x 27 Ω (555) or 47 Ω (536) in series. Later, medium speed scopes like the [[545B]] and the [[549]] use dual input followers with a [[6DJ8]] tubes and 2x 47 Ω in series at the grids, so to keep the plug-in loading approximately constant a 3.9 pF capacitor is placed across pins 1 and 3 in the scope. | The input impedance of 500-series scopes presented to the plug-in at pins 1+3 is approximately kept constant by adding shunt capacitors at the input depending on the tube type used. Early, scopes like the [[536]] and the [[555]] use a [[12BY7]] differential amplifier in the input stage, and the plug-in is loaded with the grid input capacitance with 2x 27 Ω (555) or 47 Ω (536) in series. Later, medium speed scopes like the [[545B]] and the [[549]] use dual input followers with a [[6DJ8]] tubes and 2x 47 Ω in series at the grids, so to keep the plug-in loading approximately constant a 3.9 pF capacitor is placed across pins 1 and 3 in the scope. |