Tim Shoppa wrote:
wrote:
[[Toroidal chokes]]
Problem is, if this is a restoration kind of project similar to
old automobile restoration, toroidal forms won't do...just
weren't many in the old transmitters of the 1950s and before.
Anything of the same construction type is going to be an
expensive special-order thing now. :-(

In fact, this isn't quite a "restoration to original build" type
thing, it's more of a "fix some old stuff that's been sitting on the
shelf for years and put it to use" type thing. Most of these units
are in pretty good shape, and I'm guessing that after the RF chokesdied
they were swapped around at hamfests for a few years with each
owner realizing they didn't have that choke and passing it on to the
next guy... eventually ending up with me.

In fact, Pi-w
ound chokes are still listed in the Hammond catalog and
a couple of them are stocked by AES. I ordered a 2.5mH one which ought
to be able to handle the 100mA or so that a single 6146 will need and
I'll grid-dip it and try it out.

I would still like to find a good reference on lattice-wound and
Pi-wound coil winding in a do-it-yourselfer's workshop. I think
I remember seeing a book that shows how to build a little coil
winding machine that'll do some of the ornate pi winding, and now
I kick myself for not buying it at the time.


Tim.

hi Tim,
yes, a reference to how to do pie-wound chokes would be good - jumble
wound would be fine, but its probably like cable lacing - you just want
to know how to do it for the sheer satisfaction of it hi hi !

the picture link that Wes posted looks pretty good aesthetically (and
evey toher way as well) - how was it done, how as the former made up -
looks like plastic, hopefully a follow-up post from The Man? - these
things also provide a useful way of getting B+ to the anodes of the
tubes......

I too have a "accidental" collection of old valve type amateur HF
radios - (too many, in fact) that need to be got on air as a first step
- will worry about the "authenticity" of the process later.

Andrew VK3BFA

On 14 Aug 2005 01:25:38 -0700, "Andrew VK3BFA"
wrote:

[snip]

the picture link that Wes posted looks pretty good aesthetically (and
evey toher way as well) - how was it done, how as the former made up -
looks like plastic, hopefully a follow-up post from The Man?

Ceramic.

Wes Stewart wrote:
On 14 Aug 2005 01:25:38 -0700, "Andrew VK3BFA"
wrote:

[snip]

the picture link that Wes posted looks pretty good aesthetically (and
evey toher way as well) - how was it done, how as the former made up -
looks like plastic, hopefully a follow-up post from The Man?

Ceramic.

Hi Wes,
well, not going to be able to homebrew THAT former then !

73 de VK3BFA Andrew

how was it done, how as the former made
up - looks like plastic,

Ceramic.

well, not going to be able to homebrew THAT former then !

What's wrong with, say, G-10 glass epoxy rod for winding RF chokes
around?

Is it flammability/gasses made in a choke fire that would make G-10 be
not preferred?

Tim.

Tim Shoppa wrote:
how was it done, how as the former made
up - looks like plastic,

Ceramic.

well, not going to be able to homebrew THAT former then !

What's wrong with, say, G-10 glass epoxy rod for winding RF chokes
around?

Is it flammability/gasses made in a choke fire that would make G-10 be
not preferred?

Tim.

Hi Tim,
got no idea really - over the years I have sort of got used to things
bursting into flames occassionally(sp) hi hi , so dont worry about it
but just give it a go and see what happens. I also dont leave things
running un-attended, so am not the complete lunatic I would seem.

To me, the main criteria is whats on hand - there are not REALLY huge
voltages and currents there, so a bit of latitude in the materials
selection process seems to me, at any rate, quite reasonable.

No doubt one of the space shuttle designers on this group will promptly
debunk my theories.....

And yes, I sometimes DO represent the lunatic fringe of radio - guess I
never really grew up. But I have fun.....

Andrew VK3BFA