Yaesu FT-757GX Operating Manual page 37

Once you have become familiar with the VFO/
memory transfer functions used in the preceding
examples, experiment with the transfer functions
to determine those most convenient and time­
saving in your own type of operation. Net oper­
ators will generally find it most convenient to
retain net frequencies and net QSY frequencies in
the memories, while DX hounds and contesters will
want to change the memories regularly during
operation .
One word of caution is in order, regarding the
transfer function of the M-VFO button. If the
display is showing the VFO frequency , and this
frequency is in a different band that the memory
channel frequency to be transferred , the M -VFO
button must not be pressed until after the MR/
VFO button is pressed (to change the display to
the memory frequency) . Otherwise , the displayed
frequency of the VFO will still change , but the
front-end receiver bandpass filter will not be
switched , resulting in degraded operation.
PMS (Programmable Memory Scan ) Operation
The PMS function of the FT-7 5 7GX provides the
capability for the receiver to scan between any
two frequencies within the range of the receiver,
and to stop automatically on any signal with
strength above a preset level . The frequency limits
are those stored in the (last) selected memory
channel and in the next higher-numbered channel
(unless channel 8 is the selected channel , in which
case the frequency in channel 1 will be the other
limit).
The signal level at which the scanning will halt is
set by the SQL (squelch) control, for all modes.
Scanning continues until the squelch is opened,
and therefore it can also be halted manually by
turning the SQL wntrol counterclockwise.
Before activating the PMS function, program the
desired scanning frequency limits into two adjacent
memory channels, using the techniques described
in the previous section. It does not matter which
is the higher frequency of the two channels , nor
how near the frequencies are to each other. Also,
make all positioning and/or tuning adjustments to
the antenna system , and set the RF AMP, ATT, NB
and RF gain controls to the anticipated optimum
positions (these adjustments and settings must be
made before the squelch is closed, since each
affects the squelch threshold point).
Now tune the VFO to a clear spot on the band (or
to a signal that is weaker than those you wish to
have the scanner stop on), and rotate the SQL
control clockwise just to the point where the
receiver stays silent.
Press the PMS button to activate the scanner.
Notice that the display now shows "MR" to the
left of the displayed frequency , and "P" under the
CH to the right. When the scanner locates a signal
above the preset squelch threshold , the squelch will
open and scanning will stop on that frequency . To
resume scanning, just rotate the SQL control
further clockwise to squelch off the signal, press
the PMS button again , and return the SQL control
to its original position.
When the scanner stops on a desired signal, and
you wish to terminate the PMS function there,
press the M -VFO button once . This will transfer
operation on the scanned frequency into the VFO.
Note that the function of the M -VFO button is
different in this case than when the PMS function
is not in use . In fact, if the M-VFO button is
pressed twice when the scanner has halted on a
frequency , the first push will function as described
here , but the second push will cause the VFO
frequency displayed to change again to that of the
last selected memory channel.
second push may cause improper operation if the
frequencies are widely different, as cautioned in
the paragraph preceding this the PMS description .
Example 5 :
Assume that you would like to use the FT-
7 5 7GX to listen to the downlink of one of the
amateur satellites transmitting on the 28 MHz
band (or VHF or UHF bands, using a trans­
verter ). You know the approximate direction
from which it will appear over the horizon, and
have pointed your antenna in that direction, but
you do not know what time it will appear, or
the exact frequency .
- 3 5 -
However, this