Ferrite rods as TX antennas

Overnight I tried TXing at 3W on 30m WSPR with just a ferrite rod antenna fed via a Z-match ATU. 

Although I had plenty of RX spots I only saw one on TX from an HB9. Previous attempts on FT8 were unsuccessful with just a couple of RX spots and none on TX. 

The ferrite rod was configured as an E field vertical without any earths. I suspect the ATU was lossy, but it does show that even a ferrite rod just a few centimetres long does work on TX.