SKCC 5123T----- FISTS 14979----- Flying Pigs 2331----- NAQCC 3610-----QRP ARCI 14176-----Polar Bear 257

Sunday, July 30, 2017

WSPR Comparison: Vertical vs. Dipole.

I recently obtained two WSPRlite beacons. My trip to St Andrews State Park Sunday for FOBB 2017 Flight Of The BumbleBees was an opportunity for an antenna comparison using WSPR. I compared a vertical vs. a dipole. The vertical was my N6BT Bravo 7K Vertical located directly on the South shore of Grand Lagoon. Grand Lagoon is salt water. This puts the salt water between the antenna and most of North America. The dipole was a 20-meter dipole about ten feet above the grass near the shore of Grand Lagoon. Dennis WA6QKN and I set up the antennas and hooked up the WSPRLites.

The N6BT Bravo 7K set for 20 meters and shore of Grand Lagoon

The 20 meters half wave dipole at 10 feet above the grass near the shore.

The beacons ran for one hour period between 1526 and 16:36 UTC. The dipole actually ran two minutes less. The dipole also had an extra six feet of RG-8X feed line. Using DXplorer from SOTABeam I got the following results:

Best 10 DX spots
       Vertical 2593 km average distance, max distance 3650 km
       Dipole 2057 km average distance, max distance 3410 km

Total Spots
        Vertical 150
        Dipole 87
Vertical WSPR Map

Dipole WSPR Map

My quick analysis indicates the vertical had the edge over the dipole in distance and total spots. You could have helped the dipole by more height but the ten-foot height is easy with my support poles and requires no trees. In any case, this sets the stage for future experiments including the vertical by the salt water shore vs the vertical located inland. My theory is a vertical on the salt water shore is hard to beat. We will see what the numbers say.

UPDATE: I looked at the simultaneous spot on DXplorer web site. They are listed here. Tom WD0HBR

By my count, looks like you had 34 simultaneous spots and for 21 of them the vertical showed a 10db or greater advantage.  In only 13 instances was the advantage less than 10db and only once did the dipole out performed the vertical.