[TenTec] a question:

[jack]

thank you, jack

----- Original Message ----- 
From: "Ken Brown" <ken.d.brown at verizon.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Saturday, March 11, 2006 1:10 PM
Subject: Re: [TenTec] a question:


>a friend, ham radio op and commercial radio tech, suggested that solid 
>state amps are "cleaner" than tube amps. is that "generally" true?
>
>
> There are several reasons why a tube amplifier is more likely to be
> cleaner than a solid state amplifier. Most tube amplifiers have higher Q
> output matching (pi or pi-L) networks than solid state amplifiers, which
> generally have broadband ferrite core transformers followed by fairly
> wide bandpass filters. So when properly tuned a tube amplifier is likely
> to generate less noise at frequencies far removed from the intended
> signal. Also the ferrite cores in the output coupling transformers and
> bandpass filters in a solid state amplifier can be driven into a
> nonlinear mode. An air core inductor (in most tube amplifier tank
> circuits) will not go nonlinear. In general a solid state amplifier uses
> more transistors to get the same amount of power, than the number of
> tubes used in a tube amplifier. It is easier to keep one or two tubes
> biased properly, than four or eight or more RF power transistors which
> may have have slightly different characteristics. And the required bias
> of transistors is more sensitive to temperature than tube bias is.
>
> Having said all that, a well designed solid state amp should have all
> those possible problems worked out, and be nearly as clean as a tube amp.
>
> DE N6KB
>
>
>
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