Icom IC-251A Instruction Manual page 29

Adjust the SWR SET control so that the meter needle points to ""SET'"' on the meter scale. Set the
SWR switch, located under the access cover, to the SWR position (Before your unit is shipped, the
SWR switch is fixed in place in the SET position with a plastic screw. Remove this screw before
trying to make VSWR readings). With the switch in the SWR position, SWR reading can be seen
on the meter. Although this unit is built to handle VSWR of up to 2 : 1, it is recommended that
the antenna(s) be adjusted for the lowest possible VSWR. After taking the reading, return the
switch to the SET position. You need not replace the screw.
FOR SATELLITE COMMUNICATION USE
At present there are two active satellites for amateur radio use, AMSAT OSCAR 7 was launched
in November, 1974 and AMSAT OSCAR 8 was launched in March, 1978. Satellite communications
can be made by using an IC-251A/E for receiving/transmitting and an 1C-402 (70 centimeter
SSB/CW transceiver) for transmitting/receiving in Mode B and Mode J, and an IC-251A/E for
transmitting and an IC-701 (HF SSB/CW/RTTY transceiver) for receiving in Mode A.
NOTE: FM mode is prohibited for these satellite communications.
For frequency information refer to the chart below. Further information on communicating
through satellites can be found in various amateur radio books and periodicals.
FREQUENCY CHART
UPLINK (Transmitting) DOWNLINK (Receiving)
SATELLITE | move FREQUENCY FREQUENCY BEocon
- 145.85MHz ~ 145.95MHz 29.4MHz ~ 29.5MHz 29.502MHz
(USB/CW) (USB/CW) 435.100MHz
432.125MHz ~ 432.175MHz | 145.975MHz ~ 145.925MHz
SB (USB/CW) ° (LSB/CW) tae OMe
x 145.85MHz ~ 145.95MHz 29.4MHz ~ 29.5MHz
(USB/CW) (USB/CW)
145.90MHz ~ 146.00MHz 435.2MHz ~ 435.1MHz
J
a (USB/CW) (LSB/CW) yoni Mine
SATELLITE
~97—