RadioBanter - View Single Post

Dave Heil[_2_] · March 5th 08, 08:20 PM posted to rec.radio.amateur.moderated

wrote:
On Mar 3, 2:40�pm, Michael Coslo wrote:
wrote:

Agreed - but in the Triple-F aesthetic (hereafter referred to as
"The Southgate School" or TSS), not defeating function isn't enough.
All choices must enhance or support functionality.

Gotcha, Jug!

TSS also involves the use of available materials and techniques,
usually from non-traditional sources. The rig pictured on my website
(known as the Southgate Type 7) was built almost entirely from reused/
recycled/recovered parts found at hamfests and in junkpiles. A few
crystals were bought new, as was the solder, but that's about it. The
main tuning capacitor is from a junked BC-221 frequency meter; the
dial drum is cut from a piece of Perspex tubing 6" in diameter that
came from a piece of industrial equipment, the VFO box was made (by
hand - hacksaw & flat file) from scraps of 3/32" thick aluminum plate,
etc., etc.

IOW, "found objects".

If you're willing to get dirty and are patient, it is possible to save a
bundle by using other people's castoffs.

There needs to be a chassis to place components on or in. Is
aluminum or steel or plastic more functional than brass?

Depends on the application.

For things like power supplies, steel is preferred due to greater
strength and some level of magnetic shielding. But steel must be
painted, plated or otherwise finished to prevent rust, particularly in
a basement shack where humidity may be high.

I'm going to use an old computer tower for a chassis/cabinet for a pair
of 4-400's I plan to build.

Brass has good conductivity and is easy to work, but it is heavy,
expensive, and rarer than aluminum or steel. There is some use of
brass in TSS, mostly for specialized applications where aluminum is
too soft and plating or painting steel is not practical. For example
in the Southgate Type 7, there is a shaft extender from the tuning
capacitor which I made from brass. You don't see it but it's there.

If you're building something small, try hobby shops. They often have
bins of both brass, copper and aluminum sheet in various thicknesses
along with round and square tubing and rod of the same materials.

there might be
some technical reasons fort one over the other, but in the end,
they are a support structure.

Agreed. I have used wood as well, in applications where shielding
wasn't important, or could be obtained in other ways.

Wood with a thin sheet of flashing aluminum is one way to get the shielding.

But copper plating has disadvantages too. One is that the copper
tarnishes over time. Another is that any break in the plating can set
up electrolytic corrosion. There's also the cost and relative
impracticality of copper-plating at home.

You can find a number of Heath and Drake units with really good looking
plating. I suspect that the problem units were stored in areas of high
humidity.

What Drake and others did was to plate the chassis after all the holes
were punched. That's fine for production-line manufactured rigs, but
if there's a possibility of future changes that require new holes, the
plating would be broken. So I stick with aluminum, steel, and
sometimes plastic and wood.

I think home plating of a large chassis would be so very time consuming
that not many would bother. It is also much easier to work aluminum
than steel. I wouldn't hesitate to break the copper plating for
modifying/repairing such equipment. A touch of lacquer on the edges
would keep air and humidity from getting to the steel.

TSS is about simplicity and functionality, not minimalism. If staining
or finishing improves the functionality, it is done. For example, the
shack tabletop consists of a layer of oriented strandboard (for
strength) topped by a layer of masonite (for a smooth hard surface).
This combination (actually a composite) was chosen because it was the
least expensive at the time. The masonite was given a couple of coats
of varnish because doing so improved the functionality.

The tempered Masonite, no doubt. The front panel of W4JBP's 1941
homebrew transmitter is of that stuff, painted black.

Possibly. I've had some experience building speaker cabinets (clones
of the Altec A-7 "Voice of the Theater", JBL folded horns, for
example) and the trick is to build solid from the beginning.

I've shared the experience and still remember all of the kerfing that
went into getting those curves right. Add a 15" Electrovoice SRO
speaker (which was about 3db better than anything else on the market at
the time), top is with some massive horn tweeters and you had something.

I've always wondered what the fascination with "antiques" is. I can
understand the fascination with craftsmanship, design, practicality
and materials, though.

I think there a couple of classes of antique furniture items. There are
those things which can only be viewed and those things which can be
used. A small, antique ladies chair might not be something you could
use, but an antique dining room suite or an antique sideboard can be
quite utilitarian.

The term I would use is "classic" or "timeless". Look at some Mission
or Shaker furniture - it does not appear "antique" or dated. That's
what TSS is all about, applied to Amateur Radio (and a limited
budget!)

I had to grin. I believe that 2x4's, 4x4's, plywood or hollow core
doors will never go out of style. There's no "Captain Nemo walking into
his cabin on the Nautilus" look here, but the place is attractive and
utilitarian.

Dave K8MN