Bill, W6WRT wrote:
> ORIGINAL MESSAGE:
>
> On Thu, 8 Apr 2010 21:58:55 -0700, "Hardy Landskov" <n7rt@cox.net>
> wrote:
>
>
>> Actually a match is dertermined by the ratio of the antenna Z to the
>> tranzmission line Z. The generater Z has nothing to do with it. At least
>> that is what I remember. So all these amp specs are irrelvelent.
>>
>
> REPLY:
>
> In this case, there is no transmission line and no matching network
> (pi-net), so the generator Z is important. In a normal amp, the pi-net
> transforms the tube's plate load resistance down to 50 ohms while
> adding Q to provide the flywheel effect. In this case, there is no
> pi-net, but one is not really needed for matching purposes since an
> end-fed half wave antenna presents a load resistance of several
> thousand ohms. When connected directly to the tube's plate load
> resistance, which is also several thousand ohms, you have a close
> match and a circuit Q of about one. No doubt there is some mismatch,
> but it will be in that ballpark.
>
> With a Q that low, there is very little flywheel effect and thus you
> need a separate parallel LC tank coil, not for matching purposes, but
> to provide the flywheel effect needed by any class of amp other than
> class A.
>
Do w even care if it has a flywheel effect? We really don't care what
the wave form is, we don't care about IM, or cleanliness, and we don't
care about harmonics so who cares if the whole wave form is replicated
or not?
I'd bet there's no real concern about what the signal sounds like, only
how much power is there.
73
Roger (K8RI)
> This whole thing is a little bizarre, but that's my understanding.
>
> 73, Bill W6WRT
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