For easy setup of the rig when traveling for work or whatsoever, I wanted a compact antenna, full of compromise but with descent performance and also good price.

I think the ATX Walkabout antenna is a good call. It's also known as the MFJ1899T.

For now, I've not tested it, so I just put the small instructions here : mfj-1899t.pdf

Also, from W8ABZ https://www.qsl.net/sv1uy/counterpoisekit.html, I've created a counterpoise kit with the informations below :

Edit of 28/12/2019 : tested on field with my FT-818ND. I've added couterpoise for 40m. I went on the top a hill nearby the home (120m from sea level). I was a bit surprised I received really lot of things, from CW to SSB without problems.

I tried some contacts, I was heard by a German but too weak to make some reports. After that, I was heard by MM5DWW in Scotland. My signal was weak but he was able to QSL my QRZ after several times. Unfortunately a big gun arrived on the frequency after that and I lost him.

Let's see after that for new contacts !

I've modified a camera tripod and here is the result :

I was in the top of Mont Thou near the city of Lyon in France, which is 600m high. I was able to make really solid copy contact on JS8 with this antenna on 40m (some reports were +3 dB !!).

Here is a test with just 1 radial with the length calculated above (short length) :

And with 4 radials made from 0.75mm² wire of 40m lambda / 4 length (about 10m each) :

Seems to be quite the same. I can't see lot of directivity with only 1 radial. So what to think about ?

The 1 radial solution is the ultraportable setup, and if there not a lot of difference, why bother using 4 radials, which mean more wires, more weight and extra time to install and also to fold…

Directly connected to the FT818 on a picnic table. I wasn't using counterpoise but I was however able to contact Ireland with solid copy on JS8Call on 40m.