Ferrite rod TX antenna experiments in Italy

Riccardo IU1OPK has been doing some very successful tests with ferrite rod TX antennas. on 40m.  For many this may be an answer to compact antennas. We fully accept that a bigger antenna would be better, but these results are good. Below is an extract from the email he sent me. The photos show his arrangement.

"Today I tested the ferrite antenna with WSPR on 40m and it worked well, with power from 2 to 5 watt.
I changed a little bit the design and I found that with a “short circuit” of the upper coil the signals are much stronger... below my scheme and the wspr spots (up to 2600 km).
I attempted some FT8 QSOs with no results but I have been received looking on pskreport website, so even with FT8 some qso should be possible. 

My tests were done both indoor and on my balcony so no strange coupling is noticeable, the antenna was placed vertically, I think that it works like a loop antenna oriented horizontally (not a vertical loaded one since my upper end is grounded).

The “strange” good results around midday and early evening when the critical frequency was around 7 MHz seem confirming a sort of NVIS transmission (quite strong signals and local receivers).

Riccardo's 40m
spots on WSPR

Excellent work Riccardo. Well done.  At the frontier where radio amateurs should be.

Often it is best to ignore experts and just experiment to see what works. Often the so called experts do not know and are just spouting myths they were (wrongly) told years before.