There’s always plenty of time at Christmas. Especially when the weather is not so great -
The other day I found out that a 114 - 43 fits wonderfully into an old plastic film can for photos when it is wrapped.
Now I have finally put the idea into practice and built myself a universal 1:49 balun. Depending on the wire length, I can then be active on different frequencies. I can pull up the different lengths of wire on the mast and simply change them at qsy. This way I have a suitable EFHW for many bands.
I chose a slightly thicker wire (approx. 18 AWG) so that I can also use my small 50 W PA.
Then the 2 m Coax, especially the outer conductor, acts as a part of the antenna. One of my setups with CMC is descried here.
If you compare the right CMC (in the picture) wit the film can you see, there is not much room left. The female BNC connector is long inside the can. It’s one to mount on a coax cable. I like it because of the reliability. The toroid is long to increase the conductivity. The number of windings is limited by the inner diameter of the toroid. Using the mentioned DG0SA system would not allow noticeable more windings to compensate the lower productivity by a shorter toroid to get more room for a second core.
I have several RG 174 cables of different lengths with 2x BNC in which a 140 - 43 is wrapped. Depending on the antennas I play with the position of the toroid. In addition, with the cable often gives the possibility to take a more comfortable place.
You are right, of course. For the EFHW, the coaxial cable is part of the antenna in this system.Therefore the toroid in my approx. 2.50 m short cable is also on the device side in this use.
In 95% of all my activities I am using a vertical radiator and single radial. Then the balun is at the antenna base. (I just turn the cable around)
(If you want to have the 0.05 lambda part of the 1:49 balun separately and not via the coaxial cable, you have to lead it out before the current balun. That would be then mechanically somewhat more complicated).
By the way, I have not installed a BNC connector, but the RG 174 is connected directly to the balun and a short piece is led out. If the connection is made in the hole of the toroid, you can save some space. I fixed the RG 174 from the inside and outside with cable ties. If necessary, I cut the outer cable tie and slide the cable into the box to expose everything.
Of course there would be applications where a voltage balun and a current balun connected in series would make sense… (Somehow I am not a friend of dipoles or loops in SOTA activations). If you put 2 small screws or sockets through the cover to connect the antenna wires, you could do something like this with 2 pieces of 114(-43) toroid in the photocan without any problems.