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Why-me
04-26-2016, 11:38 PM
I put a cantenna dummy load in the ground connected to an fm transmitter and the results are interesting.

The output from the transmitter itself is 10 watts. The dummy load should absorb all the radiated energy but the signal gets out farther than a 40 watt antenna.

I rode around testing the reception and it was clean and clear.

There is no modification to anything.
The only thing I did was cover the cantenna with aluminum foil and aluminum tape to keep the dirt off and cover the top with a plastic bag to further keep out the elements.

Once buried, I wet the soil to check for a difference, there was no perceived difference in output or swr.

I would like to hear from you about your experiment.

Why-me
04-27-2016, 10:59 PM
Today I took the cantenna out of the ground and after cleaning it up, I put a pvc bucket with water on the ground and placed the cantenna dummy load inside with water. I filled the bucket to a half inch of the cantennas top.

I will test the effects tomorrow.

After that test, I will dig a hole and put the whole thing in under the ground below level then cover with a lid and replace the dirt.

spacecase0
04-28-2016, 06:40 PM
remember that most coax cable is only shielded 95%, so could be how your signal is getting out
inducing ground currents can do quite well for local reception of your radio signal, there are antennas that specialize in that
when you say "a 40 watt antenna", what kind of antenna is it ?
might want to try a dipole antenna up on a mast or something that is well known as far as how well it works to see how well your setup is working
also, what is the polarization of your transmit and receive antenna ?
they should be the same to work well.
most commercial radio stations and cell phone towers use circular polarization so that any straight wire antenna works at about any angle, you loose some signal that way, but you also never loose the signal from the wrong angle

Why-me
04-29-2016, 02:46 PM
I guess the RG-8U fed into a cantenna dummy load from the grounded transmitter could have some leakage.

I better check the Q of the installation. I also need to check the Q of each connection and the Q of each operating system, before checking the Q between each circuit board.

You never know what stray capacitance could be showing up in the airspace been stacked circuits.

Thin Q for your advice spacecase0.

Why-me
04-29-2016, 05:45 PM
I cut off the end of the RG-8U plus 6 inches of the coax cable and put on a new PL 259 male connector 17111 and soldered with 60/40 lead based solder. Before I soldered the end, I made a small hole in the top of a pvc lid that fit the plastic bucket. I then fed the cable into a rubber grommet then into the squeeky tight hole of the lid. I connected the dummy load to the cable very tight and secure. I carefully placed the lid on the bucket and sealed it. I then secured the rubber grommet to the place on the top of the lid where the cable enters and sealed it from intrusion of water. I then placed the bucket in a hole well below the ground level, several feet. I covered the hole with the entire contents of the excavation site to the point of piling it up anthill style. 1711217113

The dummy load is electrically isolated from the earth and the radiated signal gets out well.

This is only ONE way to make earth transmissions possible.

I look forward to hear from anyone who is making their own type of earth antenna.
I does not have to be the same as mine.
Do you have the technology to build an earth antenna that transmits for miles on a watt or two?

Please post your results here.

Thin Q

spacecase0
04-30-2016, 12:49 AM
you might want to try a marconi antenna
https://en.wikipedia.org/wiki/Marconi_antenna
the earth is your ground (with a ground rod) and you put up a 1/4 wavelength vertical over the ground rod
I am pretty sure this gets you the best ground wave signal
depending on your frequency, this may or may not be very possible

for lower frequencies I have used a kite to pull up 135 ? foot of wire vertically (was 1.25 wavelengths on 40M minus velocity factor corrections)
worked better than any antenna I have ever used
but not much wind where I live now, so I have not played with it in a while

Why-me
04-30-2016, 12:59 AM
You have missed the point of the thread.

Anyone can put up an antenna.

Very few can use the earth AS the antenna.

spacecase0
04-30-2016, 09:14 PM
I thought you were looking for a better signal using the earth (because it can go under buildings in the correct conditions)....

many people know that you can use the earth as an antenna,
and they try very hard not to do it because it shows up faster than the sky waves and people near the transmitting station end up getting 2 signals from the same station that are not the same timing, so it messes with the clarity of the signal

now I understand what you were trying to share,
will quit trying to help in the wrong direction

Why-me
05-01-2016, 12:42 AM
Please, do not ever stop doing or trying. Your input is valuable and regarded as needful.
This way others will learn and see in their mind how to do this in more than one way.

Thin Q spacecase0, you are not wrong, only sharing on a parallel path.

spacecase0
05-01-2016, 07:23 AM
ok,
here is another idea,
have you tried transmitting when your signal is connected off to 2 ground rods with the correct spacing ??

Why-me
05-01-2016, 03:57 PM
Can you include the calculations for spacing?

Frequency = 87.5 to 107.9 Mhz........only two ground rods..........north or west........size of copper wire and clamp to ground rod.........how deep below ground level.......will spacecase0 send me photos of his sister in a bikini.......where does the cable wire hook to the driven element.........how much will cost me and can I afford it....how do you calibrate resonance and with what device......?
Ha. Humor....

spacecase0
05-02-2016, 12:30 AM
remember that is the 3 meter band you are working with,
and the ground is not the same from one place to the next,
so you are going to have to run some tests as to what the velocity factor of your ground is
after you get that number,
this might help you figure that out Velocity Factor - K3DAV.com - Amateur Radio Operator (http://www.k3dav.com/velocityfactor.htm)
found this on a google group
"Soil also has a propagation velocity. Of the order of VF = 0.15 at HF. "
from https://groups.google.com/forum/?_escaped_fragment_=topic/rec.radio.amateur.antenna/Sy1LCZSbNag#!topic/rec.radio.amateur.antenna/Sy1LCZSbNag
and with the number so low and your frequency so high,
I would likely just make a dipole antenna that I could just entirely put underground (vertical orientation would likely work best)
so each 1/4 wave wire needs to be 3M times 1/4 times 0.15
should be about 0.1125 meters long for each half, but that will change with your soil (and likely how much water it has in it at the moment),
and for anyone that does not know what a dipole antenna is, try this
Dipole Antenna | Dipole Aerial Theory | Tutorial (http://www.radio-electronics.com/info/antennas/dipole/dipole.php)
and I would think you would rather have pictures of my sister wearing a corset
not sure it matters to much what you make the antenna out of, as long as it will not corrode in the ground and conducts electricity

altnergy
10-20-2019, 11:08 AM
I love what you said and what you accomplished! I want to recreate your cantenna experiment exactly as you have done.Please advise me of exactly what I should buy and do to recreate the ground transmission you described!

I found a modern day replication the cantenna sold complete with or without oil!

God bless and God Speed!