Sub-System Requirements for Vertical Antenna

The Engineering Web

Here is a very simplistic approach to turning stated requirements to useful specifications.


Good engineering practice uses requirements to help derive specifications. These specifications are, in turn, used to guide the development of the item.

In the real engineering world requirements management is handled by dedicated programs like Telelogic DOORS or GODA Software. The relationships can be maintained from source to as many levels as one wants to track. Most engineering shops use three levels before they wind up with specifications for the sub-assembly. We will use just one level to get to the specs. Each requirement below is broken down into some design decisions and will guide the remaining development.

  1. Antenna system shall convert electrical waves from/to electromagnetic waves in the 14-30 MHz HF Bands. (Demonstrate)
    1. Antenna Radiating Conductor shall be 1/4 wave monopole at each target frequency.
  2. Antenna system shall focus energy to facilitate communications with the US West Coast and Europe from the Mid-Atlantic Eastern US. (Simulation)
    1. Antenna System should have primary angle of radiation below 45 degrees above horizon.
  3. Antenna system shall cover 20, 15 and 10 meter bands. (Test)
    1. Antenna Radiating Conductor shall be configurable for 10 meter band.
    2. Antenna Radiating Conductor shall be configurable for 15 meter band.
    3. Antenna Radiating Conductor shall be configurable for 20 meter band.
  4. Antenna system may cover 12 and 17 meter bands. (Test)
    1. Antenna Radiating Conductor may be configurable for 12 meter band.
    2. Antenna Radiating Conductor may be configurable for 17 meter band.
  5. Antenna system radiating conductor may have interchangeable and/or combinable elements. (Inspection)
    1. Antenna Radiating Conductor may have multiple breakpoints.
  6. Antenna system shall handle 1,000 watts
    1. Antenna Radiating Conductor shall handle 1,000 watts.
    2. Antenna Ground shall handle 1,000 watts.
  7. Antenna system height shall not exceed 17 feet above ground level. (Inspection)
    1. Antenna Radiating Conductor shall not exceed 17 feet above ground level.
  8. Antenna system shall shall have a diameter less than 1.5 inches. (Inspection)
    1. Antenna Radiating Conductor shall have no lumped inductances in series.
    2. Antenna Radiating Conductor shall have no capacitive and/or inductive traps.
  9. Antenna system shall have no tuned counterpoise. (Inspection)
    1. Antenna Ground shall use ground level conductors.
  10. Antenna system efficiency shall be 70% minimum. (Test)
    1. Antenna Radiating Conductor shall be 1/4 wave in physical length.
    2. Antenna Ground RF resistance shall not exceed 15 ohms.
  11. Antenna system feed-point impedance shall be between 25 and 100 ohms. (Test)
    1. Antenna System standing wave ratio (SWR) shall not exceed 2:1 at the center frequency of the vertical radiating element.
  12. Antenna system shall provide SO-238 connection point. (Inspection)
    1. Antenna System feed-point shall accept Coax with PL-259 connector.
  13. Antenna system shall utilize Commercial Off The Shelf (COTS) parts. (Inspection)
    1. Antenna System shall use components and parts from manufacturers.
  14. Antenna system shall not cause interference to electronics in the house. (Test)
    1. Antenna System shall be located at least 150 feet away from house.
  15. Antenna system shall not be visible from 50 feet away with 2" grass height except for the vertical element. (Demonstrate)
    1. Antenna Ground shall be on or under ground level.
  16. Antenna system shall be resistant to outdoor conditions. (Test)
    1. Antenna System shall use Stainless Steel where possible.
    2. Antenna System corroding metal parts shall be painted or similarly protected.
    3. Antenna System fasteners shall have use anti-seize compound between mating surfaces.


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