Galaxy 2547 modulation question

[Jim1428]

Is there a proper way to adjust the modulation on this radio so that you get the 4-1 am ratio?

The radio I have swings all the way up to 26 watts on am no matter how low I set the carrier.

Low power is set to 1 watt and high power is set to 5 watts.

SSB swings to 12 watts.

I purchased the radio new, the only adjustments done to the radio were to increase the modulation to 100% and adjust high power to 5 watts.

 

[nomadradio]

Ahhh, how did you determine exactly one hundred percent modulation? Your numbers suggest the modulation limiter is set for more than 100%

73

 

[Jim1428]

Ahhh, how did you determine exactly one hundred percent modulation? Your numbers suggest the modulation limiter is set for more than 100%

73

I put it on a scope, set 2 divisions for carrier and watched while I talked,
it goes well past the 2 extra divisions.

 

[nomadradio]

Bear in mind the amplitude of the modulation peaks should only be double the amplitude of the carrier. Since you are only looking at RF voltage, we know that the RF current will double when the RF voltage is double.

Power is voltage times current. Double voltage times double current is a four-to-one power ratio.

Brought about by a two-to-one amplitude ratio.

73

 

[Jim1428]

Bear in mind the amplitude of the modulation peaks should only be double the amplitude of the carrier. Since you are only looking at RF voltage, we know that the RF current will double when the RF voltage is double.

Power is voltage times current. Double voltage times double current is a four-to-one power ratio.

Brought about by a two-to-one amplitude ratio.

73

Thanks for the info. What started me looking at this was when I put an
amp on line. It does not make any difference what the input carrier is,
the power always swings up to 180 watts when talking, I wanted to
control the output power by varying the input but I can't with this
particular setup, the amp is a KL-703 on low setting.