Super Antenna

[Neo-X]

I will change my design into non-inductive antenna so no need for tunning and capacitor.

[conradelektro]

@Neo-X:  The "very long vertical antenna and its problems" is the kind of information I was looking for. Thank you, that was a helpful reply.


@Wings:  Thank you for posting the links to the four articles about the antennas printed by ink jet printers at Georgia Tech School. These articles triggered my thoughts about two years ago.

When reading through the articles (e.g. http://gtresearchnews.gatech.edu/device-captures-ambient-energy/ ) one sees sentences like "The scavenging technology can take advantage presently of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher."

But still, I get the strong impression that each antenna shown is only useful for a rather small frequency band. As I understand these articles: one can "print" many different antennas, each for a different rather narrow band. They mention a successful experiment where they go for the TV band.


@Madebymonkeys:  in my "long cable receiver for the 50 Hz hum" (see my last post) one measures or rather estimates "power received" by observing how long it takes to charge the 10µF capacitor to a certain Voltage.

First one looks how high the Voltage over the capacitor rises. In my house I most often can reach about 1.2 Volt. In case I place the long cable at certain locations (e.g. near the 220V mains distribution cabinet) the Voltage rises to about 2 Volt. Once this "highest possible Voltage" is established one can look how long it takes to reach it. From these three numbers, "Voltage reached", "time it takes to reach it" and "capacitance e.g. 10µF" one can calculate Wattage; of course it is µWatt. The time it takes to reach the highest Voltage is in the order of minutes.


@Onthecuttingedge 2005:  http://www.cv.nrao.edu/ntcweb/Pictures/GBSRBSantenna.jpg looks interesting, but it seems to be strongly directional (because of the parabolic dish). An antenna for receiving ambient electromagnetic waves should be good in all directions. Conventional wisdom says, that in order to increase the "gain" of an antenna, one gives it a strong directional orientation towards the transmitter. And this is exactly what one does NOT want to do when going for "all transmitters wherever they are".

My conclusion:

A very long vertical antenna would be the best but poses practical problems (expensive tower, lighning strikes, building codes will not allow it in most regions). So, one has to come up with something that has the same "properties" but is not as long and high. One should think about "electronic extension" of a vertical antenna.

Greetings, Conrad

[onthecuttingedge2005]

@Neo-X:  The "very long vertical antenna and its problems" is the kind of information I was looking for. Thank you, that was a helpful reply.


@Wings:  Thank you for posting the links to the four articles about the antennas printed by ink jet printers at Georgia Tech School. These articles triggered my thoughts about two years ago.

When reading through the articles (e.g. http://gtresearchnews.gatech.edu/device-captures-ambient-energy/ ) one sees sentences like "The scavenging technology can take advantage presently of frequencies from FM radio to radar, a range spanning 100 megahertz (MHz) to 15 gigahertz (GHz) or higher."

But still, I get the strong impression that each antenna shown is only useful for a rather small frequency band. As I understand these articles: one can "print" many different antennas, each for a different rather narrow band. They mention a successful experiment where they go for the TV band.


@Madebymonkeys:  in my "long cable receiver for the 50 Hz hum" (see my last post) one measures or rather estimates "power received" by observing how long it takes to charge the 10µF capacitor to a certain Voltage.

First one looks how high the Voltage over the capacitor rises. In my house I most often can reach about 1.2 Volt. In case I place the long cable at certain locations (e.g. near the 220V mains distribution cabinet) the Voltage rises to about 2 Volt. Once this "highest possible Voltage" is established one can look how long it takes to reach it. From these three numbers, "Voltage reached", "time it takes to reach it" and "capacitance e.g. 10µF" one can calculate Wattage; of course it is µWatt. The time it takes to reach the highest Voltage is in the order of minutes.


@Onthecuttingedge 2005:  http://www.cv.nrao.edu/ntcweb/Pictures/GBSRBSantenna.jpg looks interesting, but it seems to be strongly directional (because of the parabolic dish). An antenna for receiving ambient electromagnetic waves should be good in all directions. Conventional wisdom says, that in order to increase the "gain" of an antenna, one gives it a strong directional orientation towards the transmitter. And this is exactly what one does NOT want to do when going for "all transmitters wherever they are".

My conclusion:

A very long vertical antenna would be the best but poses practical problems (expensive tower, lighning strikes, building codes will not allow it in most regions). So, one has to come up with something that has the same "properties" but is not as long and high. One should think about "electronic extension" of a vertical antenna.

Greetings, Conrad

Hi Conrad.

actually the antenna I linked you to is a broad band receiver unit that sit in the focal spot of a 45ft radio dish. the antenna was designed for optimum reception.
the dish you saw was simply a support for the antenna.

the antenna itself is what I was pointing out since the broad band design can be arrayed in any direction.

Jerry

[onthecuttingedge2005]

One could also use this design as a broad band omni-directional but it would need proper impedance and support stand, starting. could also be used indoors for smaller models.

Just kicking the can around at the moment.

Jerry

[conradelektro]

I tried the antenna as shown in the photo, but total failure. The circuit is shown in Reply #14 in this thread.

Greetings, Conrad