On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck"
wrote:

The old "Genie" garage door opener transmitters used a ferrite rod
antenna. It was very thick and short. Like an AA battery.
Then again, that was VHF/UHF to boot. I still have one in my scrap
pile. ....Stepan

I think don't talk to much about it before reading the patent application WO
02/45210 A1 or PCT/NO01/00441. Inside there are links to other patents...
Cannot say more, must read it first.
One nice think about patents: You don't need to pay something for it if you
use it privately. Offering a device to others is not allowed. Just make your
own if possible (materials, construction, opened infos can make it
impossivble). Ideal for hams, electronics hobbyists.
My email address is real. Spam and Virus filtered.
Regards -
Henry


Stepan Novotill schrieb in Nachricht
...
On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck"
wrote:

The old "Genie" garage door opener transmitters used a ferrite rod
antenna. It was very thick and short. Like an AA battery.
Then again, that was VHF/UHF to boot. I still have one in my scrap
pile. ....Stepan

I think don't talk to much about it before reading the patent application WO
02/45210 A1 or PCT/NO01/00441. Inside there are links to other patents...
Cannot say more, must read it first.
One nice think about patents: You don't need to pay something for it if you
use it privately. Offering a device to others is not allowed. Just make your
own if possible (materials, construction, opened infos can make it
impossivble). Ideal for hams, electronics hobbyists.
My email address is real. Spam and Virus filtered.
Regards -
Henry


Stepan Novotill schrieb in Nachricht
...
On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck"
wrote:

The old "Genie" garage door opener transmitters used a ferrite rod
antenna. It was very thick and short. Like an AA battery.
Then again, that was VHF/UHF to boot. I still have one in my scrap
pile. ....Stepan

On Wed, 17 Sep 2003 19:30:19 +0200, "Arie de Muynck"
wrote:

The old "Genie" garage door opener transmitters used a ferrite rod
antenna. It was very thick and short. Like an AA battery.
Then again, that was VHF/UHF to boot. I still have one in my scrap
pile. ....Stepan

Why not in metal can? You can use for example alumina. But no
ferroelectrics! (If it's a magnetic antenna)
- Henry

Arie de Muynck schrieb in Nachricht
...

"John Miles" wrote
http://www.aftenposten.no/english/lo...ticleID=609108

I've always assumed that the performance of ferrite-rod antennas in
transmitting applications was limited by core saturation. Wonder if
there's anything to this "invention"?


I especically like the statement:
"Our tiny antenna can be placed in the car or cast in metal, and is at
least
as good"

Great, an antenna working even if cast in metal....

Arie.

"Henry" wrote ...
Why not in metal can? You can use for example alumina. But no
ferroelectrics! (If it's a magnetic antenna)

Arie de Muynck schrieb in Nachricht
Great, an antenna working even if cast in metal....


Lookup eddy currents, skin effect depth, etc.

Placing an antenna in a _closed_ conductive box is not the best way to make
an efficient antenna. Only if the box has a slot the energy may seep though
that - but that's not in "Our tiny antenna can be placed in the car or cast
in metal, and is at least as good". I see casting in metal as a closed box.
The antenna will be shielded unless they use VERY slow changing signals. Not
good for efficiency either.

Take a working old MW transistor radio with ferrite antenna and wrap it in
Alum foil. Make sure the edges make contact. You may puncture small holes to
hear the sound - or rather, notice the lack of it.

Arie de Muynck

You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics will
go thru.
- Henry

Arie de Muynck schrieb in Nachricht
...
"Henry" wrote ...
Why not in metal can? You can use for example alumina. But no
ferroelectrics! (If it's a magnetic antenna)

Arie de Muynck schrieb in Nachricht
Great, an antenna working even if cast in metal....


Lookup eddy currents, skin effect depth, etc.

Placing an antenna in a _closed_ conductive box is not the best way to make
an efficient antenna. Only if the box has a slot the energy may seep though
that - but that's not in "Our tiny antenna can be placed in the car or cast
in metal, and is at least as good". I see casting in metal as a closed box.
The antenna will be shielded unless they use VERY slow changing signals.
Not
good for efficiency either.

Take a working old MW transistor radio with ferrite antenna and wrap it in
Alum foil. Make sure the edges make contact. You may puncture small holes
to
hear the sound - or rather, notice the lack of it.

Arie de Muynck

"Henry" wrote
You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics
will go thru.

You didn't do the experiment.

Regards,
Arie de Muynck

"Henry" wrote
You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics
will go thru.

You didn't do the experiment.

Regards,
Arie de Muynck

You made great interesting experiments!
The electrical field will suffer with a alumni foil, surely. Magnetics will
go thru.
- Henry

Arie de Muynck schrieb in Nachricht
...
"Henry" wrote ...
Why not in metal can? You can use for example alumina. But no
ferroelectrics! (If it's a magnetic antenna)

Arie de Muynck schrieb in Nachricht
Great, an antenna working even if cast in metal....


Lookup eddy currents, skin effect depth, etc.

Placing an antenna in a _closed_ conductive box is not the best way to make
an efficient antenna. Only if the box has a slot the energy may seep though
that - but that's not in "Our tiny antenna can be placed in the car or cast
in metal, and is at least as good". I see casting in metal as a closed box.
The antenna will be shielded unless they use VERY slow changing signals.
Not
good for efficiency either.

Take a working old MW transistor radio with ferrite antenna and wrap it in
Alum foil. Make sure the edges make contact. You may puncture small holes
to
hear the sound - or rather, notice the lack of it.

Arie de Muynck