"David Forsyth" wrote in message
...

I recently became interested in trying to build a small two-tube regen
type
receiver for broadcast and/or shortwave reception. I designed a simple
chassis based on some vintage articles on the subject. This is the
classic
'metal box with attched front faceplate' design. I was going to use
cold-rolled steel since we have this at work and spot weld the face to the
main chassis, but then I got to thinking that perhaps the steel might
interfere with the coils. I noticed also after this that every old
article
that I've come across usually suggested aluminum for the chassis.

Your articles aren't old enough. After real wooden breadboards went out of
style, metal chassis were cadmium-plated steel. Aluminum chassis didn't
appear in wide ham use until a few years after WW2.

Nowadays I prefer using PC board for mounting components. The Al chassis
being upside-down used as a shielded base. In many cases the smaller
components can be just soldered together in "basket weave" construction
supported by the ones that need to be soldered to the PC-board ground plane.
Decades ago Pete Sulzer did his prototypes in full basket-weave style
without a ground plane - but few people can visualize ground loops well
enough to build RF circuits that way. When you visited his company you'd
see his prototypes hanging from nails on the wall.


For air-dielectric capacitors: two plates one centimeter on a side,
separated by one centimeter equals one picofarad. That's forgetting fringing
and other edge effects.

Bob C w3otc