Low Power Radio on Amazon

All the fun of low power radio with the service and satisfaction guarantee of Amazon. Please visit our
Amazon Search Page
to find low power radio gear!

The how big, how long and how many of ground radials

Medium wave broadcasters can gain significant range by adding ground radials the the base of a vertical antenna.  AM transmitters use return ground currents and the ground (and radials) are part of the antenna system.  An array of wires at or below the earth at the base of the antenna will improve the return path and increase range.

The signal strength scale is arbitrary and relative, based
on the maximum benefit derived from the highest possible
number of radials used during testing, either 120 or 60,
depending on the tester and the tests being performed.

     Controlled experiments have indicated that ground radials do not need to be much longer than the antenna is tall. A shortened antenna with loading coils will have a more compact "near field" where the majority of the antenna field is concentrated.
     The ground radials need only reach out as far as the near field extends. Field intensity decreases at the square of the distance from the base of the antenna.
     When working with the upper end of the AM band, radials around 10 feet long should be adequate.
     For lower frequencies, consider extending the radials to 20 feet.
     Use heavy wire, around 12 ga., stranded or solid core, insulated or not, whatever is available inexpensively.
     The optimum number of radials used appears to be subject to the principle of diminishing returns. Some recommend 60 or 120 radials but there is a high cost to using that many. Several hams have conducted controlled tests to determine the impact of additional radial pairs. I've plotted that data on the graph above.
     The benefit in additional signal strength appears to drop off quickly after 12 and 24 seem to yield 80% of the maximum possible benefit.
     Click here to read more about increasing range with better RF grounding for low power AM transmitters.

No comments:

Get on the Air with One Click, Buy a Transmitter Bundle from Amazon.com

Many hobbyists agree that the F-S variable power 0.1 to 0.5 W FM Transmitter is one of the best transmitters for the price.  Add the convenience of a selection of premium quality accessories and you can literally be on the air with a single click.
     No need to search the web for FM broadcast antenna, FM transmitter antenna plans or FM broadcast antenna diy, this great combo includes an F-S Electronics RangeBooster 2.0 Ground Plane Antenna. 
     Connect your antenna to the transmitter with your included ultra low-loss  (55.4 db/100m), 8 mm diameter,  rugged class 8D broadcasting cable and add your programming with the included 6 foot heavy duty stereo audio cable. 
     Necessary adapters are included, too - a simple and cost-effective solution to increase your range, minimize signal loss and maximize your broadcasting enjoyment.
     Peace of mind with the lifetime warranty.

Check out these reviews from real users:

• "All components of the bundle are high quality."
• "The Rangebooster antenna definitely extends the range"
• "Signal goes through brick-metal buildings and embankments as if they were not there"
• "The transmitter unit defaults to .1 watts which is how I've been using it."
• "I am able to get more range with the external antenna"
• "Set up was so easy. The sound quality was awesome. I love this transmitter!"
• "The transmitter works well given I am out in the 'bush' away from town"
• "Worked great right out of the box. Very pleased!!"
• "It is a very compact and easy to use transmitter with impressive stereo fidelity"

So quit wishing and waiting, quit struggling with inferior approaches and “Git er dun!”
Click below to order direct from Amazon.com
Bundle Deal #1: F-S 0.1 - 0.5 Watt Long Range FM Transmitter, RangeBooster 2.0 Professional Grade Antenna Kit, Broadcasting and Audio Cables ($300 value!)

Bundle Deal #2: 0.5 W Fail-Safe Long Range FM Transmitter FS CZH-05B + Rangemax 1.0 Antenna ($200 value!)
Bundle Deal #3: Fail-Safe 0.5 W Long Range FM Transmitter + 1/4 Wave GP Antenna Kit ($200 value!)
Power Blaster Bundle Deal #4: Fail-Safe RangeStud 15 WATT FM Transmitter + RangeMax Professional Grade Antenna ($400 value!)