Specifications

CCoouu pp lleerr TTeesstt PPrr oocceedduurree CC oonnttii nnuueedd
NNoottee::
The light bulb may not come on immediately if the coupler has not yet
been tune for that frequency. The light bulb brightness is greatest when the
coupler is tuned for that frequency.
88..22 CCOOUUPPLLEERR CCOONNFFIIGGUURRAATTIIOONN
Schematic Q30102500, sheets 1 and 2, are the schematic diagrams of the anten-
na coupler. RF input is applied through connector J5; +13.6VDC is connected
between the terminals marked +12V and GND on J7, and an appropriate anten-
na and ground system are connected to feed through insulator and stainless
steel stud respectively.
Schematic Q3330102501 is the digital design of the antenna coupler. J4 is a con-
nector for the Smartlock Pro and PTT out signal to the amplifier. J3 is for RS-
232 connection to control the tuner remotely with a PC.
88..33 TTUUNNIINNGG PPRROOCCEESSSS
An array of detector devices in the SG-235 monitors the antenna system imped-
ance, reactance signal, and the VSWR load when RF power is applied to the
unit. The computer uses the forward power detector as a check to ensure that
the measurements made are applied RF and are not spurious levels from the
data conversion system. The SG-235 will proceed to tune only when enough
forward power is present to confirm this check.
After RF is applied to the coupler, it then passes through the detector system.
The detector system consists of six capacitors in shunt on the input arm of the
51
© 1998 SGC Inc
SG-235 Manual
SGC Inc. SGC Building, 13737 S.E. 26th St. Bellevue, WA 98005 USA
P.O. Box 3526, 98009 Fax: [phone] Tel: [phone] or 1-800-259 7331
E-mail: [e-mail] Web site: http://www.sgcworld.com
SG-2000 Radio
RF IN-OUT
RF GND
SG-230 Antenna Coupler
Antenna Jack
GND