Theory Of Operation; Introduction; General Description; Simplified Block Diagram - HP 3320A Operating And Service Manual

Model 3320A/B
Section
IV
SECTION IV
THEORY OF OPERATION
4-1. INTRODUCTION.
4-2. This section contains the theory of operation for the
3320A/B. Included is a general description, a simplified
block description. a functional block description, and basic
circuit theory on unique circuits.
4-3. GENERAL DESCRIPTION.
to a crystal oscillator in the reference
se~tion.
In the
3320B. both frequency and amplitude are t:olltrolled by
BCD signals from the controller sectioll. In the 3320A. the
frequency only is cOIHrolled by BCD signals from the
COl1lroUer. The amplitude of the 3320A is controlled by a
0-13
dBm fronl panel potentiometer. The BCD sign31s
from the controller are. in turn. cOIHrollcd by front panel
switch settings or GPI B remote programming.
4-9. Controller Section.
4-4. The -hp- Model 3320A/B Frequency Synlhesizer
provides a wide range of accurate and stable frequencies
with variable amplitude settings. The frequency range is
from 0.001 Hz 10 12.9999 MHz. Five digits of frequency
resolution plus an overrange is provided in five ranges. The
3320A amplitude is variable from 0 dBm to 13 dBm into
SO
ohms by a fronl panel potentiomeler. The 3320B
amplitude is variable from +26.99 dBm 10 -69.99 dBm into
SO
ohms in steps of 0.01 dB, 0.1 dB.
1
dB or 10 dB.
~-IO.
The controller section of the
33~OA/B
processes
information from the front panel controls or the remote
inputs into BCD codes for controUing the frequency in the
3320A/B and amplitude in the 3320B. As shown in the
Controller Configuration diagram (Figure 7-6). the com-
plexity of the controller section varies with rhe 3320 Model
and Options. Refer
to
Paragraph 4-19 for a detailed block
discussion of each t:ontroUer
type.
4-6. SIMPLIFIED BLOCK DIAGRAM.
4-7.
Introduction.
4-5. Options available whieh increase the flexibility of the
3320A/B are as follows:
The discussion on theory in this section will include these
options where applicable.
FRONT
PANEL
CONTRZLS RE!OTE
I
CONTROLLEoI
I
SECJ10N
I
FRONT
PANEL
....PLITUDE
' 3 32T
ONLY)
BCD BCD
(33208
ONLY)
o Hz TO
I
FREQUENCY
I
2ONHz: TO 32.99MHz
I
AMPLITUDE
~~HZ
SECTION
r
1
SECTION
OUTPUT
10kHZ,
18MHz LREFERENCEI2NHz 20MHz
IOSCILLAlOR
I .
SECTION
Figure 4·1. Simplified 3320AlB Block Diagram.
75 ohm
OUlput
A high stability reference oscillator.
(Increases frequency stability and ac-
curacy.)
BCD
remole programming.
Two
eXLra
ranges (100 Hi. and 10 Hz) 10
increase the low frequency resolution
100.00001 Hz.
GPI B remote programming.
DESCRIPTION
007
003,004
006
4-8. The 3320A/B can be divided into four basic sections:
controller, frequency, amplitude, and reference (see Figure
4-1). The signal out of the 3320A/B is developed in Ihe
frequency section and applied to the amplitude section
where it is translated down in frequency and the level is
determined. Both frequency and amplitude are referenced
OPTION
001
002
4-1