The screw was bought (with a load of others I keep using/reusing) from a garden centre years ago.
Yes I HAVE posted whole boxes full to DX before hand so I do not have to carry and to make sure they get there and antennas fit but never had a problem with flying. I'd put in hold luggage though, security are bound to confiscate a 2 foot spike from hand luggage! A trip is not going to fail if the bag goes missing with this in it (maybe if the radio was in it too but I have never lost a bag yet), you can usually find something else to use when there. Think beach parasole base or car show room mount.
All info I have on them I posted a long time ago in 2012:
There are all sort of clones out there, YOUR local garden centre will probably do them if not then google for it... one choice was
If don't need to fly in a plane or not too worried about weight consider getting a galvanized steel one as the plastic ones do break if ground too stony.
The alternative if operating from the car might be a drive on mount and I noted Sotabeams/Richard had some at Telford and I really liked them.
The original was made back in 2013. Seriously nothing rocket science about it.
http://m1kta-qrp.blogspot.co.uk/2013/03/homebrew-lostropo-portable-dipole.html I needed a set of dipoles for multiple bands, one a time that was very very light weight so it WILL have all sorts of issues about line losses etc.
If not too concerned with trap losses, which are minor to be honest, I would make it up using SOTAbeams TRAPS as will be MUCH easier and no playing with having to pull it down and reconnect etc when changing bands.
or for more power
I like the idea of 100% homebrew but honestly by the time you have mucked about with making a PCB getting the tracks right sourcing the components you might as well use the ones from SOTABEAMS.
DO NOT use shrink wrap, in fact NEVER use shrink wrap on antenna parts that will be exposed to the weathger, especially near the sea as you will have created a lovely place for moist salty air to corrode stuff you will not see until too late. Use liquid tape to water proof the parts/joints.
4 SQ bits:
http://m1kta-qrp.blogspot.co.uk/2017/02/what-is-all-this-about-another-4sq.html follow the links on the pages especially ZL2iFB you'll find a spreadsheet in there.
4 SQ is is NOT my work but a classic and I rely on the publications ofthat of ON4UN, TK5EP, G4IFB (now ZL2IFB). I am pretty sure there is something more recent but NCJ covered options a while back including add a central 5th element (4el were enough for me) which can add ANOTHER 20dB. The gain is on RX signals not TX. You 100% CAN BUILD for other bands just scale it.
For those that want to eek that bit more out see: