Specifications

SMARTUNER MANUAL 44
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
© Nov2000 SGC, Inc. P.O. Box 3526, 98009 Fax: [phone] Tel: [phone]
E-Mail: [e-mail] Web Site: www.sgcworld.com
Detecting no forward power. When RF power is detected, the CPU will perform a test
to verify forward power is present. If no forward power is detected, the computer will
revert to the Stop mode. If forward power is detected, the CPU next checks the Hold
signal from the SmartLock. If the user has switched on the Tuned Lock function of the
SmartLock, the Hold line will be low and the CPU will not proceed with the tuning
algorithm. It will wait for forward power to be shut off and return to Stop mode.
Detecting forward power. Once forward power is detected and the SmartLock is
switched to Normal, the current coupler settings are sent to the relays. Next, the VSWR
is checked and the frequency is measured. If the VSWR is greater than 2:1 or a
difference in frequency is detected, the program branches to the re-tune program. If it is
determined that the VSWR is less than 2:1 and the frequency has not changed, the
computer returns to the Stop mode.
Re-tuning. Once it is determined that re-tuning is necessary, a test is made to see if JP2
is set to tune from memory. If the result is re-tuning from memory, settings are recalled
from the EEPROM based on the frequency measured.
The recalled data is then tested for validity. If the data proves invalid, it is bypassed and
re-tuning is performed. If the data recalled proves valid, the data is sent to the relays
and the VSWR is checked. If the VSWR is less than 2:1, the program branches to the
“OK Tuned” section of the program. If the VSWR is found to be greater than 2:1, the
program branches to the “re-tune” program.
Selecting tuning path. Several tests are made to determine which tuning algorithm or
path should be used to tune the coupler. These tests are based on frequency, antenna
input impedance, antenna phase, and VSWR. Numerous sub-routines are executed
repeatedly, depending on the status of the criteria mentioned above, in order to achieve
proper tuning.
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 LEDs and remote tune indicator
will blink on and off for about 10 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 already) 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 JP2 is set to tune from memory. If