[ARC5] [Boatanchors] Coils and the winding thereof

[Michael Tauson]

On Wed, Jul 1, 2009 at 3:48 AM, Carl<km1h at jeremy.mv.com> wrote:
> I got spoiled at a young age Mike. Living in the NYC area Radio Row was a
> short subway ride for a 14 year old with paper route or birthday/Christmas
> money in his pocket. The overwhelming amount of "stuff" had to be seen to be
> believed.

And I lived in the country in Western PA.  Surplus activity was
limited to a few locals but old radios (and TVs) to strip were
plentiful.  It wasn't until my three annual trips to Radio Row, coming
back with the springs on a '57 Ford bottomed out, that surplus got
noticed.  (That was one of two side "businesses" I had in HS - surplus
and crystal grinding to order.)

> Plug in coil forms have been around since the mid 20's and very available by
> 1930 as National, Hammarlund, and others were promoting prewound and blank
> forms every month.

Yep, and I have my eye on some UX type tube bases to handle that very
thing.  I remember seeing some period coil forms that would go well
with them but, unless I have to do otherwise, I'm staying "po' boy" as
far as possible.

> The shape of a former has no effect at the frequencies you will be working
> at. RF doesnt like right angles at high frequencies, Im not sure where the
> line is drawn.

Since my primary interest is in 160-40m (with some branching upward
later on), I'm hopeful RF has a sense of humor about having to do
corners.  :-)

> The various webs and weaves were long gone by the late 20's in store bought
> radios. They died when AC sets came along in high production in 1927 or so.
> There is a lot of info on them on the internet from crystal and battery
> radio recreaters.

Yep, and they have added to my store of knowledge.  The comment about
"store bought" radios is important because it's those same radios that
provided parts for the "po' boy" equipment during the 30s.  My mentor
(for those pieces) told me that sometimes the coils were used intact
(or less a few turns), though carefully watching power was necessary
to prevent burning them out.

> Most of the real poor component and material ideas were gone by the time the
> 36 ARRL HB came out.

Only for new stuff.  Some of what I'll be using will be more or less
current with that HB while other pieces will be older, some going back
to the 20s and some definitely homemade.  The transmitting micas are
part of that first group as are the variable caps (although I may
sneak in a homemade sliding plate variable cap somewhere.)  Crystal
holders will be mostly contemporary with maybe one or two open holders
used when just the crystal element itself was swapped and not the
whole thing.

> My own interests start primarily with the 1935 metal tubes. There werent
> many decent RF RX or TX choices before that ( The 1935 HRO is an exception)
> and battery tubes are totally useless IMO except as shelf queens. Same with
> the majority of the earliest AC sets. About the only one that gets somewhat
> regular use here is a Radiola 18 for Red Sox games.

Hmmm ... got any of those battery bottles you don't want?  :-)

Best regards,

Michael, WH7HG
-- 
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Hiki Nô!