I don't know how you test a new amp for stability
but an unloaded state is the best way. If it's
not stable unloaded then it's not stable. What
the hell is "every amp manual" ?
Paul
Paul Hewitt
WD7S PRODUCTIONS
QRO HOMEBREW COMPONENTS
http://wd7s.home.att.net
> -----Original Message-----
> From: Bill Turner [mailto:w7ti@dslextreme.com]
> Sent: Wednesday, August 08, 2001 6:47 PM
> To: wd7s@arrl.net
> Cc: amps@contesting.com
> Subject: Re: [AMPS] Linear AMP timing
>
>
> On Wed, 8 Aug 2001 18:32:19 -0700, Paul
> Hewitt wrote:
>
> >Hi Bill
> >IMHO the best way to control
> bias/cathode current
> >is by means of solid-state switching.
> It will be
> >faster than either I/O relay operating at <2ms
> >make and <1ms break. The bias (on/off)control
> >transistor operates saturated so a
> little goes a
> >long way dissipation wise. I use the
> same control
> >buss for I/O relay control and bias switch.
> >Paul
>
> ________________________________________
> _________________
>
> I agree about solid-state switching,
> but IMO, the tube should be still
> biased off until switching is complete,
> both input and output.
> Otherwise, the tube could see a brief
> unloaded condition, which has been
> known to cause trouble.
>
> True, many amps are stable in an
> unloaded condition, but every amp
> manual I've seen advises against it.
> I'd just rather be safe than
> sorry.
>
> Bill, W7TI
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