Table of Contents
Advertisement
At this time, there are 2 primary concerns which preclude acquiring phase lock.
1
.
The 331 4A's output frequency is limited to
value.
2. The reference frequency change must be within the bandwidth of the
phase locked loop.
The approximate bandwidth of the phase locked loop can be determined using this
formula:
B. W .
(OISPLA::O FREQ )
where A ;::; 1 if the EXT REF FREQ is
A
5 if the EXT REF FREQ is
=
Note that the 331 4A will not update its frequency
out of lock (the Fin
The 3314A's
phase-lock
oscillator frequency using the VCO or FM modulation capabilities.
Use the VCO input if you have
quency. You will probably have to turn auto-acquisition off with FREQ Range Hold
and set the 331 4A's center frequency manually. Any error between the VCO in-
put
signal
and the reference frequency must be corrected by the 3314A's PLL and
hence, must be within the loop bandwidth. The 3314A's output frequency can
+
range
10% to -50% without losing lock.
Note that when the 3314A's output frequency deviates
displayed frequency, one of the
Indicat e an out of lock condition.
MODE
N light flashes) and Frequency Range Hold is OFF.
capability can be greatly extended if you
signal that is proportional to the reference fre-
8
LCK lights will flash. This does not necessarily
64
(cant)
+
10% and -50% of the displayed
.72
<
2MHz
2MHZ
display
3314A's
unless the loop goes
pre-tune
>
10% from the
its
Advertisement
Table of Contents
