Ssb Power Measurement; Output Power Measurement By 2-Tone Signal - Furuno FS-1575 Service Manual

Ssb radiotelephone

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5.1.3 SSB Power Measurement

The power of the SSB (J3E) transmitter is defined by peak envelope power.

Peak envelope power is the average power supplied to the antenna by a transmitter

during one radio frequency cycle at the crest of the modulation envelope, under normal

operating conditions.

1. Set the frequency of the AF GEN-1 and -2 to 700 Hz and 1700 Hz or 1100 Hz and

2500 Hz, respectively, and then make adjustment of output level of the AF GEN so

that the two AF GEN will come to the equal transmission spectrum.

700Hz/1100Hz

1700Hz/2500Hz

In order to input a microphone rating of −36 dBm, set the output power of

AF GEN-1 and -2 to "−36 dBm + 6 dB = −30 dBm" taking into account the

insertion loss resulting from two signal pads.

2. Modulate power at a specified input level to ensure that the 3

not more than −25dB for the transmission spectrum.

3. Read "Peak envelope voltage-1: E1" in the said state on the oscilloscope.

CONFIDENTIAL (internal use only)

This confidential document is used only by FURUNO authorized persons.

It is strictly prohibited to reproduce the document in whole or in part without prior written permission of FURUNO.

approx. -36dBm

Fig. 5.1.1 2-Tone Measurement Circuit

5.1 Overview of Output Power Adjustment

Oscilloscope

IMD component is

Fs-2575 Fs-5075