1-01-09 09.26, skrev i4jmy@iol.it på i4jmy@iol.it följande:
>
>> An amplifier capable of
>> 3000 watts being operated at 500 watts can easily have more IMD
>> than an amplifier capable of 550 watts operated at 500 watts.
>>
>> 73, Tom W8JI
>> w8ji@contesting.com
>
>
> Working in a linear region, two amplifiers using an identical
> configuration and similar devices, if properly biased and tuned for the
> wanted output level, doesn't necessarily produce an IMD advantage for
> the larger one compared with the smaller amplifier, although in most of
> the cases their IMD figures are quite comparable and acceptable.
> Things anyway quickly go in favour of the bigger amplifier when the
> smaller amplifier is starting to compress more in order to obtain a
> stated output power level.
> As a matter of facts and expecially with smaller amplifiers, some of
> the manufacturers claim irreal output levels and others "forget" to
> explain that beyond a certain output power their amplifier is already
> compressing a lot.
> On the other hand, amateurs are prone to believe in miracles and tend
> to (largely) overdrive smaller amplifiers in order to obtain more power
> (often the manufacturer claim is already too much) and expecially to
> obtain more reading from their AVG wattmeters, whose fact is well
> obtained when the PA is compressing.
>
>
> 73,
> Mauri I4JMY
>
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
>
>
The advantage with the bigger tube is that you can operate it in almost
class A for legal output with low relative distorsion level ( as compared
to peak output). You need a good cooling system using a BIIIG blower plus
a BIIG power supply using a BIIG hivoltage cap. A good way of warming up
Scandinavian and Siberian ( -50C? right now?) homes in the winter ,hi!
de Hans SM5KI
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