Richard wrote:
> >Definitely not multi band or even multi frequency. Single frequency only.
> >From what I understand they were a real pain to keep tuned properly.
>
> I heard the same thing.
>
> >Advantage was high level modulation and class C efficiency without the usual
> >big high level modulator.
> >
> A Class AB1grid-driven, or AB2 g-g linear amplifier is typically 60%
> efficient. Class C may be 78% efficient but the difference would be
> virtually not noticeable at the Rx end or on the utilities bill.
>
> cheers, Gary
With AM though the carrier efficiency is only about 30% with a linear amp. The
amp needs to be tuned at and able to handle 4 times the carrier power to handle
the audio peaks for 100% modulation. Most stations run upwards of 120% positive
peak modulation making the amp PEP power handling requirement even greater than
4
times carrier. Efficiency will be even less in that case. Lots of heat to get
any
kind of real power on AM with a linear amp.
73
Gary K4FMX
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