Specifications

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© 2003 SGC Inc. 50
Signaling “no
-
tune.”
Should the initial primary tuning sequence
prove unsuccessful, secondary algorithms are attempted until all
possible routines have been exhausted. If, after the secondary
attempts, the coupler still cannot achieve a proper VSWR, the
program branches to a “no-tune” program. Here, the LED’s and
remote tune indicator will blink on and off for about 15 seconds to
tell the user a proper VSWR could not be found. After the
indicators stop blinking, the program waits for forward power to
cease (if it has not ceased al-ready) and returns to stop mode. At
this point the user should try several other frequencies. If the “no-
tune” condition persists, check the installation of the antenna,
coupler, radio, and ground system for possible problems.
Signaling “OK tune.” If the coupler achieves a good VSWR
during the tuning sequence, the program branches to the “OK
Tune” section of the code. Here, the tune indicators are engaged. A
test is then made to check if JP3 is set to tune from memory. If so,
the frequency is measured and the tuning elements used are saved
in memory coupled with a verification code. Once saved, a test is
made on JP1 to check if the duplex mode has been selected. If so,
the transmit tuning elements remain in circuit until the receive
mode is verified. At this time, all tuning elements are removed.
The frequency is then saved for future comparison and the CPU
reverts back to the STOP mode.