[Milsurplus] RAL Hum

[Marty Reynolds]

>
> I don't recall if i had posted this RAL factoid to  this list or only
> GB, but there's a paragraph in a Navy maintenance book ( 900,103 ?? )
> that mentions using preferred tubes in the RAL detector and/or RF
> stages. Some brands of tubes had the heater wound in a different
> pattern, which created more AC hum. That sound familiar? ( I'm not
> making this up. )

It's twoo, it's twoo.  Some heaters were twist-wound & it's reported
they're best for hum-reduction.  Most were rip-rap affairs.

Easy to tell what you've got by looking @ one lit up.

It's only the detector that matters in the hum equation