Mailing: PO Box 3526, Bellevue, WA 98009
Shipping: 13737 SE 26th St., Bellevue, WA 98005
Toll-Free: 800-259-7331 • Phone 425-746-6310 • Fax: 425-746-6384
www.sgcworld.com • Email: sgc@sgcworld.com
12
© 2001 SGC, Inc.
removed and the 'tune' indicators are turned off. At this time the
computer reverts to a "sleep" mode awaiting RF power or pushbut-
tons S2-S8 in Manual Mode.
4.1.1 Auto Mode
Detecting forward power. Once forward power is detected and the
optional SmartLock is switched to Normal, the current coupler set-
tings are sent to the relays. Next, the VSWR is checked and the fre-
quency 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 JP3 is set to tune from memory. If the result is re-tuning from
memory, settings are recalled from the EEPROM based on the fre-
quency 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 tun-
ing algorithm or path should be used to tune the coupler. These tests
are based on frequency, antenna input impedance, antenna phase,
and VSWR. Numerous subroutines are executed repeatedly, depend-
ing 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 pos-
sible 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,
SG-239 Manual
page 12
Wednesday, October 17, 2001 08:31
Composite
To Next Page
