This afternoon, I did a quick test of the “matchbox” end fed antenna from the Honolulu Emergency Amateur Radio Club, up on a hill, good receptions reports using only 5 to 7 watts, as you can see below – the sun was setting and the band was closing. As a caveat, I am not doing any sort of absolute judgement on this antenna’s performance, just a bit of field test feedback!
The antenna UnUn was connected to the radio through 12 feet of RG8 coax – with this sort of design, the coax shield does act as a counterpoise, so the antenna won’t perform properly without it. The creators of the antenna recommend 16ft or more for the coax for good performance.
I actually did a PSK31 QSO with an operator using 2W on his side, and my side on 5W ! The antenna is fairly small, and very convenient to carry around along with the radio.