I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

1. We already have a form that is circular (no waste) and
with an accurately-positioned central hole.

2. There is a metallic film sandwiched between the plastic.

3. Is this film to thin to stand up to the RF currents that
will spread out across it when charging & discharging?

4. How would we make metallic contact to the film without
destroying the film at the point of contact?

5. Does anybody know the type of metal making up the film, i.e.,
can we solder to it?

6. Is the plastic of a suitable quality? Will it arc-through?

On Thu, 13 Jan 2005 13:09:02 -0000, "Airy R.Bean" wrote:

| I wonder if there is any mileage to be had from adapting
| the numerous junk-mail CD's as the vanes of ATU
| capacitors?

I make mine into Christmas decorations.
Stick in pairs using double sided foam pads, on monofilament fishing line.
Dangle a lot of these strings inside a window.

--
Dave Fawthrop dave hyphenologist co uk
Killfile and Anti Troll FAQs at
http://www.hyphenologist.co.uk/killfile.

On Thu, 13 Jan 2005 13:09:02 -0000, "Airy R.Bean"
wrote:

I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

1. We already have a form that is circular (no waste) and
with an accurately-positioned central hole.

2. There is a metallic film sandwiched between the plastic.

3. Is this film to thin to stand up to the RF currents that
will spread out across it when charging & discharging?

4. How would we make metallic contact to the film without
destroying the film at the point of contact?

5. Does anybody know the type of metal making up the film, i.e.,
can we solder to it?

6. Is the plastic of a suitable quality? Will it arc-through?

A little Googling would soon show you whether the critical factor,
which you doubtless have already determined from your preliminary
calculations is the loss tangent for the CD substrate, may well render
such a use as inadvisable.
--
from
Aero Spike

Airy R.Bean wrote:

I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

So you've given up on using them to make 30 line television systems then?

Do a web search about this - plenty of info - though you claim you don't
web search.

David.

"David Edmonds" wrote in message
...
Airy R.Bean wrote:

I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

So you've given up on using them to make 30 line television systems then?

Do a web search about this - plenty of info - though you claim you don't
web search.

Superficially the idea has some merit but you would have to machine the
discs anyway (they are totally symetrical and thus the area overlapping with
the fixed vanes wouldn't change). By the time you've machined then to be
asysmetric, might as well have made metal plates and avoid all the other
problems as well.

To problems in making variable Cs, the use of a CDROMs offers little.

Etching plates on PCB and using the fibre glass for the mechanical side is
maybe a better idea.

--
Brian Reay
www.g8osn.org.uk
www.amateurradiotraining.org.uk
FP#898

Hardly - you have the cost of purchase and the inconvenience of
etching. Junk mail cd's are free issue.

"Brian Reay" wrote in message
...
Etching plates on PCB and using the fibre glass for the mechanical side is
maybe a better idea.

"Brian Reay" wrote:

: Etching plates on PCB and using the fibre glass for the mechanical side is
: maybe a better idea.


hey everybody...brian has made capacitors (or is that capacitErs ?)

"David Edmonds" wrote in message
...
Airy R.Bean wrote:

I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

So you've given up on using them to make 30 line television systems then?

Do a web search about this - plenty of info - though you claim you don't
web search.

And if your realy bored http://www.scitoys.com/

"David Edmonds" wrote in message
...
Airy R.Bean wrote:

I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

So you've given up on using them to make 30 line television systems then?


Just like the TMC days. One daft idea after another.

Nimrod wrote:
"David Edmonds" wrote in message
...

Airy R.Bean wrote:


I wonder if there is any mileage to be had from adapting
the numerous junk-mail CD's as the vanes of ATU
capacitors?

So you've given up on using them to make 30 line television systems then?



Just like the TMC days. One daft idea after another.



I remember turning vinyl discs into flower pots, but some of us have
moved on since then.
--
;)
73 de Frank Turner-Smith G3VKI - mine's a pint.
http://turner-smith.co.uk