I was forced to use magloop (also known as STL - small transmitting loop) because I don't have permission to build antennas on my roof.
For loop I use cheap heating pipes. Any magloop builder inevitably will have to solve high quality/voltage capacitor problem. Since I operate only CW I decided to try fixed capacitor made from coaxial cable (first two pictures). This was working solution but it's hard to make it waterproof (it's very important!)
Then I tried to make capacitor from the heat pipe too. This is very good solution - it's easy to make adjustments, it's easy to make it waterproof with heat shrink!
I made already quite a few QSOs with the 5W transceiver published earlier, even with some JA stations.
The only concern so far is overall temperature stability - I will report my findings later here.