User`s manual

SG-211 User’s Manual

The output of the L network can be left floating to drive

balanced antennas or one side can be grounded for

unbalanced antennas. Providing the balun on the input

side of the network means that it is normally operated

with a matched load. Locating the balun on the output

side as in some other tuners, means that the balun sees

much more stress with a mismatched load.

4.3 The Sensor

Transformers T2 and T3 form a directional coupler. D1,

D2 and associated circuitry detect forward and reverse

power that is fed to the microprocessor A/D inputs. The

microprocessor wakes up when the forward power

exceeds the minimum threshold. If significant reflected

power is detected, the matching sequence is initiated.