5a-17
Theory of Operation
A13 Pulse Modulator (8648B/C/D Option 1E6)
A13 Pulse Modulator (8648B/C/D Option 1E6)
The pulse modulation module is a thick film circuit mounted inside the instrument. The
main inputs are:
• RF output from the A10 frequency extension module
• TTL pulse from the rear-panel PULSE IN connector
The module is supplied with −15V, +5V, GND, data and enable lines, from the A3
motherboard assembly via a twisted wire assembly. If Option 1E2 is present, the power
and lines are routed from the motherboard via the A14 modulation generator assembly.