radio8z

Mram,

Thanks for sharing your project and the link to the picures and description are very nice.

There is certainly a lot to be gained by experimentation and it is nice that you shared yours with us.

Mram,

Thanks for sharing your project and the link to the picures and description are very nice.

There is certainly a lot to be gained by experimentation and it is nice that you shared yours with us.

As we experiment and build and test antennas, it seems there is someting missing though. I recently reported on my design for a colinear antenna but I apologetically could not report on its performance since I know of no basis for comparison to others or a workable practical field strength measurement.

You did report a 1/4 mile good signal range with yours which is probably significant. But since you mentiioned the Thomas Edison approach I began to ponder this.

I do not mean to detract from what you did and I think you should keep experimenting, but Mr. Edison did not do things the way many have been led to believe. When he developed the electric light bulb, he tried many filaments, many vacuuums, many currents and voltages. He was happy when one of his bulbs burned for 2 days….this was success since previously his filaments burned for seconds. According to my readings, he knew what materials were possilbe filaments and which were’t and began to make selections based on the theories of vaporization, combustion, and electron emission.

The key feature from Mr. Edison is that he compared one design against another and decided which was better based on experimental data. But his experiments showed that carbonized cotton did not work as well as other materials He knew this because he did experiments with different materials and by measurement, some were better than others. He was guided by experience and theory of materials.

From these data he was guided to the the best electric incandescent bulb that he could produce. It became commercially viable, yet it was later vastly inproved by researchers at General Electric who discovered how to draw tungsten to a filament which was far superior to Edison’s carbon threads. Had Edison not laid the groundwork, GE would not have perfected it.

Edison was not a person who just tried things until they worked, his experiments were based upon known science and he knew where he was going. A common misunderstanding of Edison is that he just threw things together, stirred the parts on the table with a soldering iron, and chose those which worked. If you visit the recreation of Menlo Park N.J. at the Ford Dearborn Museum in MI you will get a sense of the orginization and science he applied to his research and that he had funding, a machine shop, glass blowers, and a large scientific staff at his command..

So, taking some guidance from Edison, you have devised an antenna system and have published it here for us to review. You claim, and I do not doubt that it works. The problem with all of us who post our ideas is that we have yet to develop an objective way to compare our results. Edison measured the time that his lamp filaments burned objectively, yet we only subjectively measure the performance of our antennas. I would like to compare my antenna to yours so we need to come up with a way to objectivaly accomplish this. I am open to ideas.

Richard Fry has posted here the theortetical maximum field strengths for a base coil loaded antenna working against buried ground radials in normally conductive soil. Here is the target. We need to develop a repeatable means of measuring our antenna design performance against a standard whereby we can judge, as did Edison, which one works better than another. It is highly unlikely that any of us can exceed the established theoretical maximum performance predicted by the theory as presented by Mr. Fry but wouldn’t it be fun if we did? We don’t need to have FCC accurate measurements of field strength, we just need to come up with some way to have repeatable and reproducable readins.

Your contribution to the body of knowledge is important and apprecitated. You have designed and built a workable antenna which others can use, however we still do not know if it is optimum as measured against the theoretical objective. Keep your antenna set up until we can agree on how to compare it with other designs and with the theoretical ideal.

We can learn for Mr. Edison, and we can learn from theory.

Neil