Antenna length for the WSPR tracker
So, there are a few factors that impact the ideal length of the antenna for the WSPR tracker. The classic wavelength formula is:
wevelength = 984 feet / Frequency in MHZThis is adjusted by the velocity factor of the wire, which is also impacted by whether or not the wire is insulated. I found several resources discussing wire length. Conventional wisdom seems to be to adjust by between 4-5%. W7NAT likes 5%. This would be for ground-mounted antennas.
However, we're using very thin wire, and we're in free space. I'm going to try a full 1/4 wave with no adjustment.
|Antenna scenario||Element length (inches)|
|20m 1/4 wave dipole for 14.0971. No Adjustment.||209.4|
|20m 1/4 wave dipole for 14.0971. 4% adjustment for insulation.||201.0|
|20m 1/4 wave dipole for 14.0971. 5% adjustment for insulation.||198.9|