More on Ground Radial Systems

That's a link to direct facts about radial grounds and why they're needed for any AM station setup, and something good to start with or think about adding to your station.

I wish I'd known how important the ground system was back when I had a tube transmitter at home back when I was in high school. I had a decent wire out of the window, and my ground was just what was recommended for receivers with long wire antennas, water pipe ground and electrical power system ground in the house.

I probably would have had better signals if I'd made the effort to get some wire and put it out as radials. My dad wouldn't like tripping on wires in the grass, and might have put a stop to my broadcasting.

If I'd known it was this important, I'd have fanned out some radials under the antenna. I know I tried a piece of wire as one radial, but it didn't seem to help the signal. Now I know why, it wasn't a good ground return or shield for the ground.

Boomer

Wow Jim Henry 2000, your gardener must really LOVE you! I remember when they cut some of your radials by mistake.

One good thing about transmitting with low power is that if an un-initiate contacts the ground system or antenna, they're unlikely to be hurt or shocked from it.

I did get shocked on a friend's AES one tube transmitter, but that was from the DC plate voltage, not the antenna. It did make me recoil and yank the cord, but otherwise wasn't a bad shock, just surprising.

Boomer

I have imagined it.. When I was in school and got entranced with AM radio and broadcasting, 5 watts was one power I thought of having, nice even number, based on the idea of CB, which was 5 watts input at one time.

I never knew what the range would be, enough for neighborhood broadcasting, basing it on the kits getting 50 feet on their low power of milliwatts. I learned about what tubes could do with audio, and thought something like a 6AQ5 tube could do 5 watts nicely on AM band.

If you'll get shocked on RF seems to depend on the power, and the impedance of the antenna where you touch it. Antennas build up lots of voltage at the tip, even 10 foot ones. I don't know for sure what that voltage is, but I'm thinking it could be a few hundred volts, knowing what Tesla coils can do, and they're about the same as a Part-15 antenna.

You don't get shocked touching it because the P-15 power is low, and if the antenna touches anything conductive, it's instantly detuned by hand, so very little current passes to your skin.

I'd think you could start feeling it at a watt, and at 5 watts probably draw an arc with a pencil tip and light a nearby fluorescent tube by proximity at 5 watts.

That could be some concern if we get higher power for hobbyists one day, but then CB talkers and hams have had few problems in dealing with it, it would be just something to get used to.

Boomer

Well I do make a great effort to staple them solidly to the ground with landscape pins.

Deep Earth Grounding

Jim Henry breaks new ground: "From driving around I'd say it's about a 5-10% improvement. I have not re-tuned the antenna yet but I'd expect that will help a little more."

Thoughts of "water table" and "underground wells" came into my head a few weeks back and speculation began to question whether part 15 transmission could benefit from connecting to underground water.

This is a thrilling discovery and I encourage you to bring it over to part15_us where other members can wrap their heads around it.

Yeah they cut two more yesterday.....