[R-390] Solid State rectifiers vs Tubes

[David Wise]

> From: Scott, Barry (Clyde B) [mailto:cbscott@ingr.com]
>=20
> I was looking over the changes to the HP200CD audio signal=20
> generator and I found where they went from solid-state=20
> rectifiers to a tube rectifier.  That seems rather odd to me.=20
>  Why would they have decided to go back to a tube rectifier? =20
> The change notice included distortion figures.  Would a power=20
> supply configuration with a tube versus solid-state diodes=20
> have lent itself to a cleaner signal?

Beats me.  Are the distortion numbers better or worse than
what was published before?  Sometimes they find out they
can't make them consistently as good as they originally
said and have to back-pedal a little.  The 8640B change
history has several examples.

More likely the SS diodes they were using turned out to
be unreliable or more expensive than the tubes.  Just a
guess, YMMV.  Let us know the real reason if you find out.

73,
Dave Wise