End fed halfwave antennas

These antennas are popular as they cover many bands and are easily erected. Especially with high power, RF in the shack can be an issue.

At the end of a halfwave the impedance is high so they are usually fed via a wideband transformer to bring the impedance closer to 50 ohms.  Wideband transformers are usually 1:49 or similar. On their harmonics the radiation pattern can be very odd.

They can be useful antennas, but are a compromise.

End fed half-wave antennas?

These are multi-band antennas (K24) are end fed via a transformer so the high impedance is reduced to somewhere nearer 50 ohms. I see AliExpress is selling them for around £30 shipped to the UK. 

As a QRP operator, the limited power handling does not bother me. Usually I operate at about 5W. 

With high power some have reported RF feedback, often cured with a small counterpoise or choke on the coax. I am tempted to see how this works. I doubt I could make one for that price.

Banggood is selling similar ones for even less.

The end fed halfwave antenna (EFHW)

Steve G0KYA has a nice pdf document he's created describing how to make simple end fed half wave antennas (EFHQ). These band specific antennas can be very effective and simple when mounted either vertically or horizontally. They can be made with PVC covered wire, fishing poles or aluminium rod. See http://www.infotechcomms.net/downloads/Endfed_halfwave_dipoles.pdf.  Many years ago we experimented with these on VHF handhelds and achieved results some 6dB better than with a standard 1/4 wave whip, but on 2m they were on the long side! On HF they are capable of low angle radiation good for DX.