System Requirements for a Vertical Antenna
The Engineering Web
The quest for a 20/15/10 meter vertical antenna starting with requirements.
After studying many ARRL and other fine references on antennas I became enchanted with the promised DX capabilities of vertical antennas. One requirement constantly preached is the need for a good solid ground plane system most often achieved with a good wire radial system.
Backing up one step, here are some requirements to first establish what I seek.
- System Goal:
- An Antenna System shall be designed to facilitate communications in the upper high frequency band from 14 - 30MHz to the US West Coast and Europe from the Mid-Atlantic US East coast QTH while remaining inconspicuous. The antenna system shall be fixed in place within property lines without benefit of supporting structures and shall maintain a feed-point at ground level to allow connection from underground coax.
Antenna System Requirements (with Verification Method):
- Antenna system shall convert electrical waves from/to electromagnetic waves in the 14-30 MHz HF Bands. (Demonstrate)
- Antenna system shall focus energy to facilitate communications with the US West Coast and Europe from the Mid-Atlantic Eastern US. (Simulation)
- Antenna system shall cover 20, 15 and 10 meter bands. (Test)
- Antenna system may cover 12 and 17 meter bands. (Test)
- Antenna system radiating conductor may have interchangeable and/or combinable elements. (Inspection)
- Antenna system shall handle 1,000 watts
- Antenna system height shall not exceed 17 feet above ground level. (Inspection)
- Antenna system shall shall have a diameter less than 1.5 inches. (Inspection)
- Antenna system shall have no tuned counterpoise. (Inspection)
- Antenna system efficiency shall be 70% minimum. (Test)
- Antenna system feed-point impedance shall be between 25 and 100 ohms. (Test)
- Antenna system shall provide SO-238 connection point. (Inspection)
- Antenna system shall utilize Commercial Off The Shelf (COTS) parts. (Inspection)
- Antenna system shall not cause interference to electronics in the house. (Test)
- Antenna system shall not be visible from 50 feet away with 2" grass height except for the vertical element. (Demonstrate)
- Antenna system shall be resistant to outdoor conditions. (Test)
Fortunately for me I have a large back yard with plenty of room for the extensive ground radial system as shown here...
In the coming weeks each step of this design process will be documented in the hope it might be useful to someone interested in their own vertical monopole antenna. Installments will include:
- Refine requirements to Sub-Systems
- Identify Sub-Systems Specifications
- Prepare Bill of Materials
- Select location in yard
- Water drill hole for mounting pipe
- Prepare area around pipe to counter sink radial ground system
- Specify and build monopole for one band
- Attach monopole to ground pipe and wire
- Specify and perform testing of feed point impedance vs. number of radial wires with first monopole
- On air tests