Microverts are very small vertical antennas, weird, controversial and fun, probably most popular in Germany.
Since I have to get along with very limited space on the roof, I have tried several kinds of antennas suitable for such limitations. One kind I came across were "microverts". This kind of antenna has been developed by DL7PE and DL7AHW, with a modification by DL7AXO that seems to be popular. All three are German callsigns, so you may understand why this kind of antenna has become popular especially there.
The original sites by DL7PE and DL7AHW seem to be gone and both have become a little bit silent, because... Well, these antennas are a bit controversial and did not meet all the claims about them. So what is a "microvert"? The basic idea was like with other antennas to open the capacitor in an LC circuit, but this time there is a "large" capacitive part at the top, followed by a coil. This ends in a radial and an air choke, both made out of coax. You can find an image and an on-line calculator here .
The antenna is also known as "spraycan antenna" or "beer keg antenna " because of the materials used for the capacitive "radiator". (You can even use tinfoil.) According to the designers, it is this capacitive part that radiates. The antenna is very easy to build, and also fun to build. It looks weird, but still somehow works. And in theory it does allow you to get on the air with a very small antenna. The antenna is however very sensitive towards its environment, so you better adjust it after you installed it. Because it is also a very narrow bandwidth antenna, DL7AXO suggested to couple through a capacitor , which does indeed help a lot. A wire on top may also help for finetuning.
So far, so good. The creators have probably become a bit silent because this design did not live up to the advertisements. DJ5IL has debunked the claims thoroughly and bilingually. Again, physics refused to be raped. You can build small antennas, but they can not also be very efficient antennas. This does however not mean that this design may not be suitable for you. If you are looking for a (small) fun antenna, one that is also fun to build, you may very well try it. No special parts are needed. I built two, one for 7MHz from a can of sauerkraut and one for 50MHz, with tinfoil around a milk bottle. After all, amateur radio should also be fun, right?