Rohde & Schwarz ZPV Vector Voltmeter
Internals

(click images to enlarge)

Internal construction – individual modules plugged into a motherboard, individually shielded. Two extender boards are included inside the unit having their own stowage slots.

CPU board, classic Intel 8080 system. 1 KByte RAM (2 × 2114), 6 KByte EPROM (3 × 2716)

(All boards shown in maintenance position, plugged into an extender.)

The central D/A converter board – one 8-bit D/A with discrete multiplexer and per-channel sample/hold. The LM339 on top is used for software-based A/D conversions.

EPROM memory extension board.
Impedance and s-parameter functions were software options originally.
There are already some 2732s on this board (4 KBytes each)

"Selection Channel A".
Most transistors in the ZPV are socketed!

IEC bus (IEEE-488) interface board.
The IM5200 is an early (1975) PLA chip.

"Digital Filter" board
(switched–capacitor filter)

Power supply (section) with fan.
The fan still has external electronics!

Amplitude detector board.
Feels like '80s hobby kits, doesn't it?

The keys/display board.
Uses smart numeric displays (TIL311).

Interior view of E1 Tuner Plug-In (10 Hz–50 MHz)

Interior view of E2 Tuner Plug-In (100 kHz–1 GHz)