hybrid wspr decoding experiment

To test the theory that some duplicated bad decodes are the result of multiple strong stations being received, I looked in the wspr database for VK3 transmitters on 2m over the past month.

I found 29 VK3 callsigns that were hybrid decodes (3 different stations transmitting, resulting in 4 different decodes).

I ran 4 instances of wsjt-x - one as a receiver and
the other 3 as transmitters (through virtual audio cable). The transmitters were at 1480Hz, 1500Hz, and 1520Hz - this created several signals across the entire waterfall every 20Hz.

I was able to generate the callsigns/grids in the left column by setting up the other 3 instances of wsjt-x to transmit the calls/grids in the other 3 columns.


Hybrid call - Transmitter1 Transmitter2 Transmitter3
----------- - --------------------------------------
VK3BTJ-QF22 - VK3YE-QF21 VK3BQ-QF22 VK3YCQ-QF21
VK3BWA-QF22 - VK3FZ-QF22 VK3DXE-QF21 VK3KZM-QF21
VK3CKU-QF22 - VK3DXE-QF21 VK3YE-QF21 VK3ZTE-QF22
VK3CPI-QE13 - VK3ZAZ-QF12 VK3BQ-QF22 VK3YCQ-QF21
VK3D-QF22 - VK3MDH-QF22 VK3MHY-QF22 VK3EEK-QF22
VK3DFZ-QF21 - VK3ZTE-QF22 VK3BQ-QF22 VK3YCQ-QF21
VK3DGP-QF22 - VK3DNS-QF22 VK3YE-QF21 VK3YCQ-QF21
VK3DQB-QF21 - VK3DXE-QF21 VK3YE-QF21 VK3YCQ-QF21
VK3ECA-QF22 - VK3YE-QF21 VK3EEK-QF22 VK3YCQ-QF21
VK3FWD-QF22 - VK3DXE-QF21 VK3BQ-QF22 VK3KZM-QF21
VK3GOR-QF22 - VK3ZTE-QF22 VK3KZM-QF21 VK3YCQ-QF21
VK3GRA-QF22nh - VK3YE-QF21 VK3ZTE-QF22 VK3KZM-QF21
VK3KSJ-QF21 - VK3KZM-QF21 VK3YCQ-QF21 VK3YE-QF21
VK3KWC-QF22 - VK3KTT-QF22 VK3YE-QF21 VK3YCQ-QF21
VK3LZL-QF21 - VK3DXE-QF21 VK3MHY-QF22 VK3DNS-QF22
VK3MAV-QF22 - VK3YE-QF21 VK3MHY-QF22 VK3YCQ-QF21
VK3NJN-QG30 - VK3OE-QF22 VK3YCQ-QF21 VK3ZYC-QF31
VK3ORH-QF02 - VK3YE-QF21 VK3OTR-QF02 VK3YCQ-QF21
VK3PGL-QF21 - VK3OE-QF22 VK3DXE-QF21 VK3DNS-QF22
VK3POP-QF22 - VK3QN-QF22 VK3LU-QF22 VK3MO-QF22
VK3PRY-QF21 - VK3DXE-QF21 VK3MHY-QF22 VK3BQ-QF22
VK3QJG-QF21 - VK3MHY-QF22 VK3ZTE-QF22 VK3YCQ-QF21
VK3SZF-QF22 - VK3KN-QF21 VK3DXE-QF21 VK3MHY-QF22
VK3TEI-QF21 - VK3KTT-QF22 VK3DXE-QF21 VK3MHY-QF22
VK3TXD-QF21 - VK3MHY-QF22 VK3BQ-QF22 VK3KZM-QF21
VK3YII-QF22 - VK3DXE-QF21 VK3EEK-QF22 VK3YCQ-QF21
VK3YPL-QF22 - VK3DXE-QF21 VK3EEK-QF22 VK3YE-QF21
VK3ZEB-QF22 - VK3DXE-QF21 VK3DNS-QF22 VK3YCQ-QF21
VK3ZMB-QF22 - VK3YE-QF21 VK3ZTE-QF22 VK3YCQ-QF21

Most of the hybrid decodes I found were the result of 3 transmitters. There were some that only had 2 transmitters in the wspr data, but I was not able to recreate the hybrid data by transmitting only 2 calls. Others had more than 3 transmitters which I did not test.

Mark - KB9AMG