Back when I opened the “Indoor Antenna Project”, which is still going on, I tested a baseboard ground run around the baseboard of several rooms down by the floor, and indeed it allowed the AMT3000 with my self-wound triangular shaped loading coil tune up to a perfect resonance, except that outside the house the signal only reached the sidewalk.
Tonight I devoted over 10-minutes to changing the ground, by removing the baseboard wire, and grounding the transmitter right below the floor with a clamp attached to the main I-beam that holds up the floor.
The I-beam is electrically grounded to water pipes, furnace ducting and has iron posts holding from the floor.
To tune the thing back up I needed to find a different tap on the coil but now the resonance is back to a peak and tomorrow we will be driving around in search of new footage covered on 1550kHz.
Part 15 radio is just large enough to escape needing a microscope.
Experimenting
is good, especially when the results are shared. One thing to watch for when using a structural or electrical system ground in a building is noise associated with appliances running. This happened here when I was using a water pipe as a ground. Mechanical vibrations, even those caused by people walking, would appear in the audio as a scratching or “static” sound. This is completely gone since I moved the transmitter outdoors with its own radial ground system.
Neil
Reminders
Your experience with the water pipe reminds me of a year ago when I first tried an I-beam clamp down at the other end of the house, and did get some rather loud buzz in the transmitter.
This other end of the beam seems quieter, but big surprises could be yet to appear,
Since the above post I walked down to the sidewalk, where the previous 1550 setup was very weak, and now it’s strong down there even though it’s night time.
First impression is that outdoor coverage is improved.
Ideas Arrive
Ideas come to those who think, and it happened to me.
After Radio8Z mentioned picking up noise from indoor grounds, I went from radio to radio and found that we are very lucky this time, because 1550 is quieter than it was before.
With the baseboard ground there were various hums that rose and diminished with certain appliances being turned on, but now the carrier is as pure as the cotton in a pill bottle.
To celebrate I will throw a huge new years weekend starting right away.