1:1 UnUn, Choke BalUn

A few days ago I noticed that, while trying to work on 40m from mobile, my Icom IC-7000 suddenly stops, powering off.
So, investigating the trouble I put a (very) Ugly Balun at the output of the radio.
The problems went off so I planed to make some sort of Choke balun.
This broadband transformer is a 1:1 and block the current mode current.
Here it is the making off:

LE:
The main reason for making it with two RF connectors is that the choke is used in mobile installation and after it there is a small lenght of coaxial cable.
 73 de YO3HJV