Ham Radio - Ground spike antenna. Using the earth to receive LF and VLF 

Yes that's how VLF transceivers work. If you amplitude-modulate a 1000 Hz baseband tone on a carrier more than twice the baseband frequency (Nyquist Theorem) that is >2 x 1000 = above 2000 Hz using a software like audacity or gnuradio and amplify it with an audio amplifier of say 100 W and instead of giving the signal to a Speaker connect the cable pair with these ground rods after carrying out impedance matching you can achieve the goal. But remember VLF signals can also be detected by UFOs much effectively as they communicate in ELF, ULF and VLF ranges, so be careful. ELF and ULF bands are full of anomalies. I once used my very low frequency response sound box Xonar X7 from Asus with an induction coil as antenna. And I generated a 25Hz Chirp Signal for 30 seconds from speakers of another laptop. The spike appeared on the receiver spectrum. Then I stopped the signal generation. The spike was gone. But it reappeared after a few minutes and remain their for the same duration for which I generated. And then vanished. Then again it appeared after the same gap but it was faded and then for the fourth time. Those were the echoes of the same signal bouncing back from probably the earth crust or stratosphere. I have no idea.

Spikes need to be as far apart as you can get them when you go full scale

Sounds like a great friend! I definitely wouldn’t mind sharing a friendship with somebody with the same interest as me

@@bhamptonkc7 You are correct. I experimented with this for years and am getting back into it. I had two rods driven in the ground almost a quarter mile apart and got over a quarter mile receive range. One could put the transmitting rods on either side of a small village and everyone in the village could pick up the signal at their house by two rods in the ground in their flower bed only a few feet apart. It's a really cool covert communication method. I built two transceivers and talked through the ground with my neighbor across the street, it was awesome. Unfortunately he only had the interest to try it one time when I spent money buying the copper ground rods and wire and wanted it to be a regular thing. I wish I had someone of like interest close enough for me to do that again.

oncydium I can well imagine the police in UK allowing somebody setting up a ham station at the side of a British motorway. Technically, I'd be concerned whether or not each section's joint was adequate! Same with using a long fence wire in a farmer's field!

i've considered using local train tracks but not tried it yet

Yea that would be interesting. You could put a 50Hz notch filter in the system this time and try again. There's no reason you couldn't do the same thing with solid state amplifiers and their phono inputs, or even use the auxiliary input and your own pre amplifier that has the 50Hz filter built into it

Plans

@@moonjockclark9491 Well its been years since I made it but its nothing fancy I assure you. I don't have a schematic actually I just kind of threw it together (thats how I role over here). Capacitor coupled throughout with .022 MFD caps. The first stage (the MPF102 in grounded source style) probably has like a 100K from the gate to ground with a .022 MFD from the input jack to the gate. The source resistor is going to be around 220 to 470 ohms bypassed to ground with a .022. The drain is probably has like a 1K going to the 9V rail. A .022 from the drain on that one to the base on the next stage (2N2222 in grounded emitter config). The base bias is going to be like a 47K from base to 9V rail and 4.7K from base to ground. Emitter resistor is like 220 ohms to ground and bypassed with a .022 MFD. The collector has probably a 470 ohm to the 9V rail and a .022 MFD to the output jack. For your VLF antenna make an X frame thats about 18-20 inches per side. The first winding is 9 turns across a 5 section tuning cap (365 pf per section) with all 5 in parallel. The other winding is just 1 turn connected to the input of the preamp. I put a switch in line with the battery so I can save battery live when not in use. You used to be able to get one free battery per month from Radio Shack back in the 70s. Not anymore. So save that battery by installing the switch!. Thats all I can tell you. Give it a shot and see. You will know it works if you hear the static level come up when you turn it on. Oh and some additional info I just thought of. The first stage is a FET because it has a high impedance input which helps preserve the Q of the tuned circuit (the loop antenna).

Thanks

that's a BIG antenna then i'd like to see what kind of reception you'd have gotten

Yep, the Kenwood was hooked to my usual 98 foot end fed I've talked about before. I'll be getting some realy ground rods soon and expanding on this experiment. It's really got me curious.

There are plenty of them out there, but they don't use AM anymore, they use MSK or FSK modulation.

Can u get electricity from it?

Actually, that was likely a time sync signal. Phase modulated, I think. There's probably info out there on decoding the data. And yes, if it were military VLF transmissions, it would be encrypted.

Soon. FCC has cleared it, waiting on official status.

@David Henry Meaning what?

@David Henry Okay, apparently you don't know what AM means. It means amplitude modulation. It has nothing to do with the frequency.

@David Henry Let me try again to bring this down to your level. When you say "AM and above" you are obviously talking about a frequency range, the "AM broadcast band," roughly 530-1700kHz (properly called the mediumwave band). I was not asking about that. Amplitude modulation is perfectly feasible at lower frequencies. I was only asking whether anyone had the experience of using a ground spike antenna to send or receive an amplitude modulated signal, in the frequency-range where this kind of antenna actually works (at least for CW). This is a question that you obviously lack the knowledge to answer, since you could not even understand the question. Your initial response made no sense to me because it had nothing to do with what I was asking.

The SDRPlay RSP2 has three antenna ports. One of them is a high-z port that consists of a three wire terminal input. The three lugs are ground, low side, and high side inputs. I attached the wires between the L and H terminals, ignoring the ground terminal. The common way to connect a higher impeadance antenna.

ah ok thanks for that don't have a rsp2 but so want one. Thanks for the info.

It's something I want to revisit someday.

If you're referring the the end fed the Kenwood was hooked to, it's 98 feet fed with a 7.5:1 UNUN. I covered it on my video about my home antennas: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-9o0plMeKR7w.html

I was actually asking about the vlf antenna with the spikes in the ground..... Is it fed like a dipole???

Yes, just as shown in the vid. This week I'll be replacing the electrodes with 6ft copper clad ground rods and trenching the wire feeders about 6 inches down, leaving just the twisted pair feedline above ground.

What's 'cubic'?

SDR program.

I am planning on trying that also. Mine is 103' and has been a great ground for radio work.