[Amps] ceramic vs glass

[Ian White]

> 
> It's not the Ceramic Vs glass that requires the protective circuits, it
> is the internal structure of grid and screens with very little
> dissipation that require the protective circuits.  When 8877s were $300
> you didn't see much in the way of protection.  Now the Eimac versions
> are over a kilobuck, over drive protection has become popular, so too
> has the awareness of IM products.
> 
> It's the lack of awareness that has given Tetrodes a bad name.  The
> 4CX1500B and Chinese FU728F have very good IM products and are quite
> linear when operated correctly and not over driven.  (Tuned and loaded
> as a Tetrode and not as a triode)
> 
> 73
> 
> Roger (K8RI)
> 
>
Exactly. The increased need for protection isn't due to any differences
between glass and ceramic construction, but all the other internal changes
that were introduced at the same time - along with ever-increasing
replacement costs.


73 from Ian GM3SEK