HP 8340b User Manual

20-30
Loops
Overall
Theory
of
Operation
The
20-30
loops
provide
the
YIG
oscillator
loop
with
a
synthesized
reference
signal.
The
YO
feedback
circuitry
phase
locks
the
YO
to
the
20-30 loops output
signal
as
explained below:
NOTE:
The
phase
lock
loops PLL2, PLL3,
and
PLL1
are
usually mentioned
out
of
numeric order
(e.g.
instead
of
PLL1, PLL2,
and
PLL3
order).
Instead,
they
are
mentioned
in
functional
order.
PLL2 is
the
first
phase
lock
loop,
then
PLL3, followed
by
PLL1.
IN
CW/MANUAL
MODE
The
20-30
loops
directly
phase
lock the
YO.
PLL2,
PLL3, and
PLL1
operate
together
to
produce
high
resolution
tuning
of the
YO.
IN
SWEPT MODES
The 20-30
loops
are
used
in
three
different
ways,
depending
on
the
frequency range
over
which the
YIG
oscillator
is
swept.
YO
Sweep
Width
is
Between
100
Hz
and
5
MHz
The 20-30
loop
is
swept
in
this
mode,
and
the
output
of the
20-30
loops
sweeps
the
YIG
oscillator.
The
other
tuning
inputs to
the
YO
loop
are
held
constant.
YO
Sweep
Width
is
>5
MHz
The 20-30
loops
provide
phase-lock
reference
to
the
YO
only
at
the
beginning
of
the
sweep
When
sweep
begins,
the
YO
phase-lock
loop is
opened,
and
the
YO
Is
swept
by
analog
means.
Table
C-l.
20-30 Loop
Operation
vs
YO
Sweep
Width
YO
Sweep
Width
100
Hz
to
5
kHz
and
CW
Mode
>5
kHz
to
100kHz
>
100
kHz
to
5
MHz
Loops
Used
PLL1
X
X
-
PLL2
X
X
X
PLL3
X
X
-
PLL2VCO
Divided
By:
500
25
5
PLL1
Divide
By
10
ON
ON
OFF
Total
Divide
Number
5000
250
5
20-30
Output
Resolution
1
Hz
20
Hz
1
kHz
20-30
Loops
Overall
Theory
of
Operation
HP
8340B/41B

HP 8340b Specifications

General

Brand	HP
Model	8340b
Category	Inverter
Language	English