[Amps] filament instant heating query

[Rob Atkinson]

Didn't know that.  I always figured the AL-80s were simply over driven
so the Ip went way over 400 ma.  I have heard of owners having to get
a new tube every 3  years or so.  What is the stock fil. v.?

tnx

Rob
K5UJ

On Fri, Jun 15, 2012 at 11:34 AM, Carl <km1h at jeremy.mv.com> wrote:

> Now you take a poorly designed/marketed amp such as the AL-80A/80B which
> runs the filament voltage high to start with so it can meet its inflated
> 1000W PEP rating. The end result is that it forced a step start to be
> included in late AL-80A production and all 80B's. The filament is still over
> spec in standby using the factory set transformer taps and using a bucking
> winding will bring it down to 5.0 no load at the socket and 4.8V at full
> power out.The end result is a bit less RF but hopefully much longer tube
> life.
>