
below 10 volts, the coupler will go into a retuning sequence.
For this reason, SGC recommends that if distances are great, the input DC
voltage at the transmitter site be adjusted to provide for 12 to 14 volts at the
coupler site.
We do specifically advise against use of a different power supply than is used
to power the radio because of the danger of creating ground loops which may
cause oscillation of the final amplifiers or other undesired side effects. If you
decide to use a separate power supply mounted at the antenna coupler location,
please be advised that SGC does not provide technical support in this area.
1
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The current version of the SG-230 coupler will have a revision number or let-
ter located on the printed circuit board. The first Smartuners were lower
numbers or early in the alphabet. More recent version of the coupler are in
the "T" range of the alphabet and beyond.
The Smartuner is one of the most finely tuned products on the market. Each
revision of the coupler includes the newest circuit designs in order to contin-
ue moving the state of the art forward in coupler design.
The original Smartuners with Revision numbers prior to "R" were usually
three wire sets plus coax. In other words, the coupler control line was not
available.
With the advent of Revision R, the reset line was added to allow the operator to
force the unit into the bypass mode on receive (useful for broadband scan-
ning) and to find the lowest possible SWR under a given set of conditions on a
single particular frequency.
Revision T of the coupler was the next major move forward with the addition of
the locking function to keep the coupler from retuning.
SGC will continue making incremental improvements in the Smartuner prod-
uct. When you buy your product today and a new feature is added, you can
always upgrade for modest fees to the latest version of the unit. The versions
change are infrequent now, however, because the unit is so highly refined
and meets the needs of HF professionals.
However, if you ever hear a long time Smartuner user saying they would like
to upgrade to the latest version of the unit, have them contact SGC because spe-
cial discounts are provided to our customers.
15
© 1998 SGC Inc
SG-230 Manual
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA
P.O. Box 3526, 98009 Fax: 425-746-6384 Tel: 425- 746-6310 or 1-800-259 7331
E-mail: [email protected] Web site: http://www.sgcworld.com