Een modulatie meter voor AM, hier zie je er een in actie. Links is de negatieve modulatie en rechts de positieve. Het ledje wat knippert geeft aan dat er 125% modulatie is.
@@RoelandJansen I would think that the equipment is safely at maximum output without distortion. And to your good point the "headroom" is occupied and there is no distortion. As long as those lines are straight. It's really part of how the broadcaster has to consider when engineering the station. Using a linear amplifier for AM requires that is has a LOT of reserve power to be used in the AM mode. We don't think of this when we use a plate modulated tube style transmitter. Except, here we go again, there is reserve power in the modulator amplifier that impresses the audio to the carrier. Example:::::a 1,000watt AM transmitter needs a 500 watt audio to fully modulate a 1,000 watt transmitter. And it's the positive peaks which gives the loudness that you need that reserve of power from the modulator to be loud on the air.
@@adriancressy8363 I was more thinking of the input level itslf Maybe it's normalized or compressed. My Mixer has a headroom of somewhere in the 20 dB. Maybe I better could have asked how the audio chain looks like ;-) Re AM modulation depth and such I should know that stuff given the hamradio background, telecoms I did when I was young etc ;-) I do have made soms AM QSOs on HF; fun stuff. (and occasional fm on 10m repeaters)
PERFECT straight lines on the 'Scope for trapezoid pattern...NO distortion and plent of headroom
how much headroom is left if you are at that level?
@@RoelandJansen I would think that the equipment is safely at maximum output without distortion. And to your good point the "headroom" is occupied and there is no distortion. As long as those lines are straight. It's really part of how the broadcaster has to consider when engineering the station. Using a linear amplifier for AM requires that is has a LOT of reserve power to be used in the AM mode. We don't think of this when we use a plate modulated tube style transmitter. Except, here we go again, there is reserve power in the modulator amplifier that impresses the audio to the carrier. Example:::::a 1,000watt AM transmitter needs a 500 watt audio to fully modulate a 1,000 watt transmitter. And it's the positive peaks which gives the loudness that you need that reserve of power from the modulator to be loud on the air.
@@adriancressy8363 I was more thinking of the input level itslf Maybe it's normalized or compressed. My Mixer has a headroom of somewhere in the 20 dB.
Maybe I better could have asked how the audio chain looks like ;-)
Re AM modulation depth and such I should know that stuff given the hamradio background, telecoms I did when I was young etc ;-)
I do have made soms AM QSOs on HF; fun stuff. (and occasional fm on 10m repeaters)