SRK Electronics MFTX100, Operation And Service Manual, Page: 29 / 100

MFTX AM TRANSMITTERS
SRK Electronics 29
8.2 Audio Functions
8.2.1 Gain control
The transmitter is designed to accept peak audio input levels from +10 to -
10dBm. The gain control allows the user to set full modulation at any audio level
in this range.
The gain control is adjustable from 0 to 100% in 1% increments.
The optimum gain setting will depend on the audio input level. Lower levels will
require more gain than higher levels.
Note that due to the advanced design of the MFTX, it is not necessary to change
audio gain when changing set power. The ratio of carrier power to audio level is
entirely determined by the gain setting.
8.2.2 Modulation metering
The transmitter includes metering of peak positive and negative modulation.
The peak hold function lasts for one second and is then updated.
8.2.3 Compressor
The audio compressor function is not currently implemented.
8.2.4 Limiter
The transmitter incorporates a peak limiter that allows independent setting of
positive and negative limits.
The limits are calibrated in arbitrary units from 0 to 255. They are factory set to
limit at
-95% and +125% , but can be changed by the user, or the limiter can be
turned off completely.
Note that setting the negative limit excessively low, or the positive limit
excessively high, will affect the other limit level.