HP 8340A Service Manual page 101

Rl3 and Cll are part of the feedback network that determines the
frequency response of the M/N Phase Locked Loop.
Loop Frequency Response section in the A31 M/N
circuit description.)
A32Al Buffer Amplifier
The Buff er Amplifier provides both isolation and gain for the vco
output signal. Ll provides an impedance match to the cavity output
for the base of Ql,
Rll provide the de bias for Ql.
fhe amplifier ,
Buffer Amplifier provides at least 0 dBm output over the 355 to
395 MHz range of the VCO.
8-136
Model 8340A - Service
B
the amplifier transistor. R3,
and R2 and L2 provide the output impedance. The
Scans by HB9HCA and HB9FSX
Phase Detector
R3 provides negative feedback for
(See also the M/N
RS, R7, RlO, and