Hi fella's
Let me know if I should go to another group.
We're doing experiments with UHF antennae,
design.
CD's have a conductive aluminum substrate,
and diameter in UHF range.
We got into experimenting with them and have
unusual results, some very good, using them
as reflectors and directors.
Anyone else screwed around with these?
Regards
Ken S. Tucker

"Ken S. Tucker" wrote in message
oups.com...
Hi fella's
Let me know if I should go to another group.
We're doing experiments with UHF antennae,
design.
CD's have a conductive aluminum substrate,
and diameter in UHF range.
We got into experimenting with them and have
unusual results, some very good, using them
as reflectors and directors.
Anyone else screwed around with these?
Regards
Ken S. Tucker

Not yet, but how would you "fine tune" one as a director?
Wire antennas are easy to tweak by clipping a bit off the ends.
Lots of folk pick a material easy to work with, but CDs may not fit that
category.

Ken S. Tucker wrote:

...

How about the aluminum platters (disks) out of old used hard drives?
They seem they would be much easier to work with ...

JS

On 27 Jun, 18:23, "Hal Rosser" wrote:
"Ken S. Tucker" wrote in ooglegroups.com...

Hi fella's
Let me know if I should go to another group.
We're doing experiments with UHF antennae,
design.
CD's have a conductive aluminum substrate,
and diameter in UHF range.
We got into experimenting with them and have
unusual results, some very good, using them
as reflectors and directors.
Anyone else screwed around with these?
Regards
Ken S. Tucker

Not yet, but how would you "fine tune" one as a director?
Wire antennas are easy to tweak by clipping a bit off the ends.
Lots of folk pick a material easy to work with, but CDs may not fit that
category.

I have used those as spreaders for elements with
8 wires strung/hooked around the periphery to make extra
diameter elements. In the early days servers were giving
them away to attract customers
Art

In article ,
Hal Rosser wrote:

Not yet, but how would you "fine tune" one as a director?
Wire antennas are easy to tweak by clipping a bit off the ends.
Lots of folk pick a material easy to work with, but CDs may not fit that
category.

Perhaps one could use a compass, and simply scribe a circle of
appropriate radius through the aluminized layer? Experimentation
would be required, as the area outside the scribed circle would
probably act as a capacitive load for the director disc inside.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Hal Rosser wrote:
"Ken S. Tucker" wrote in message
oups.com...

Hi fella's
Let me know if I should go to another group.
We're doing experiments with UHF antennae,
design.
CD's have a conductive aluminum substrate,
and diameter in UHF range.
We got into experimenting with them and have
unusual results, some very good, using them
as reflectors and directors.
Anyone else screwed around with these?
Regards
Ken S. Tucker


Not yet, but how would you "fine tune" one as a director?
Sand paper?

Wire antennas are easy to tweak by clipping a bit off the ends.
Lots of folk pick a material easy to work with, but CDs may not fit that
category.

On Jun 28, 10:04 am, (Dave Platt) wrote:
In article ,

Hal Rosser wrote:
Not yet, but how would you "fine tune" one as a director?
Wire antennas are easy to tweak by clipping a bit off the ends.
Lots of folk pick a material easy to work with, but CDs may not fit that
category.

Perhaps one could use a compass, and simply scribe a circle of
appropriate radius through the aluminized layer? Experimentation
would be required, as the area outside the scribed circle would
probably act as a capacitive load for the director disc inside.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Thanks all for your answers and questions.
I'm less than competent in understanding
antenna design, though I've installed 100's
of them and studied a fair amount physics.

Recall that a loop antenna is good for UHF,
the closest thing in antenna theory would be
a folded dipole receiver. (I'm thinking of Hal's
question here), what sort of director-reflector
would improve a loop antenna?

Dave's "scribe" suggestion sounds interesting.
I wonder if discs may have advantages over
over conventional wire elements, perhaps due
to capacitive effects?
Regards
Ken

On Jun 27, 12:45 pm, "Ken S. Tucker" wrote:
Hi fella's
Let me know if I should go to another group.
We're doing experiments with UHF antennae,
design.
CD's have a conductive aluminum substrate,
and diameter in UHF range.
We got into experimenting with them and have
unusual results, some very good, using them
as reflectors and directors.
Anyone else screwed around with these?
Regards
Ken S. Tucker


I've never messed with them, but I used to have a microwave TV
antenna that used disks as the directors, or whatever..
That portion of the antenna was a long rod that stuck out of
the housing which held the driven element I assume.
The rod was filled with tube spacers and small aluminum disks,
one after another. So it's been used, but like I say I've never
messed with one, or even used the TV version I had. It was just
an antenna I picked up out of a bunch of other junk..
Just find one of those old TV microwave antennas that they
used to mount on houses, and you will see "disk" elements.
I don't see why the CD's couldn't do the same, but of course
they are tuned to one, or at least a fairly narrow range of
frequencies if they use the stock disc size without trimming.
I'm not sure of any advantages.. Maybe one.. The elements
are naturally good to go with either polarization. Seems you
would only need to change the driven element polarity to
change from one to the other. BTW, the one I had, all the
disks were the same size.. And they were much smaller
than a CD.. Maybe 2 inches dia max?
MK