661 Series plug-in interface

The Tektronix 661 oscilloscope mainframe takes two plug-ins: the sampling plug-in (e.g., 4S1) and the timing plug-in (e.g., 5T1).

Overview

The sampling plug-in interfaces with the Type 661 mainframe via two multi-pin connectors:

  • P1 Power Connector
  • P2 Readout Connector

The timing plug-in interfaces with the Type 661 mainframe via two multi-pin connectors:

  • P3 Digital Readout Connector
  • P4 Interconnecting Plug

There is also a pair of coaxial cables terminating in Gremar connectors connecting the sampling plug-in to the timing plug-in. The coaxial cables are part of the mainframe, but are not electrically connected to the mainframe. They just pass through.

Sampling Plug-in Interface

P1 Power Connector

Pin Function Comment
1 unused
2 unused
3 −19 V
4 −25 V
5 −100 V
6 Staircase In
7 Ground
8 B Out To Horiz
9 Ground
10 B Vert Out
11 A Vert Out
12 Ground
13  unused
14  unused
15 +300 V
16 unused
17 +100 V
18 +19 V
19 Staircase Out
20 ground
21 blanking
22 ground
23 ground
24 Vert Sig Out

Pin group function legend

 DC power 
 AC and heater power 
 Deflection and Trigger Signals  
 Control Signals 

Timing Plug-in Interface