Bus cable Wiring for HP 8566/8568 Spectrum Analyzers

This information relates to the Bus Cable for the HP 8566/8568 Spectrum Analyzers series.

Wiring on display end corresponds to pin numbering stamped on “DB-50” connector. Wiring on RF “centronics connector” end is as listed below with connector contacts facing you and long side of “D” to the left:

• 50 49
• 48 47
• 46 45
• 44 43
• 42 41
• 40 39
• 38 37
• 36 35
• 34 33
• 32 31
• 30 29
• 28 27
• 26 25
• 24 23
• 22 21
• 20 19
• 18 17
• 16 15
• 14 13
• 12 11
• 10 9
• 8 7
• 6 5
• 4 3
• 2 1

My Amphenol P/N 57-33500-1 50 pin connector has pins 1,25,26 and 50 labeled on the actual connector.

This would make what is:

Labeled Pin 1 on the “RF” connector actually Pin 2 on the display connector

Labeled Pin 26 on the “RF” connector actually Pin 1 on the display connector

Labeled Pin 25 on the “RF” connector actually Pin 50 on the display connector

Labeled Pin 50 on the “ RF” connector actually Pin 49 on the display connector

Not too confusing, is it!

Thanks again,

Mike WA2YGA