[Amps] Parasitics & Filament Sag

[Tom W8JI]

> Rich said:
>
> "813s don't need a VHF suppressor because they are pushing 
> the limit
> at 28MHz."
>
> On the contrary, I remember seeing a single 813 amp for 
> 50Mhz in a handbook
> somewhere. Also, my problem was spur generation in the VHF 
> region. Now
> whether other components were involved with this, I don't 
> know. I do know
> that the spurs were eliminated after the nichrome 
> suppressors were
> installed.


That's exactly opposite the truth anyway.

The most stable tubes are those with the highest operating 
frequency limits.

73 Tom