A Dream has come true ...
(background info about the BABG180 housing)
Home-brewing wire antennas is still a good idea, even these days. Commercial ready made products are mainly hand-made and, as a consequence of that, cost their price. For this reason home-brewing is economical and a lot of fun at the same time. It doesn't take too much time and does not ask for high-brow expertise. That is why we have specialised in providing a wide range of wires, ropes, and all kinds of hardware useful for building wire antennas. However, a suitable housing for baluns was not available for the DIY-enthusiast so far.
Generally, industrial standard housings do not meet the requirements needed for antenna building, as they are not designed to stand high break loads and more often than are not weather- and uv-proof for long term use.
Most commercial baluns are hermetically sealed or moulded in epoxy for lasting reliability, surely an elegant and technically perfect method. However, if they are taxed too much by high power or by tuning on frequencies that they are not made for, they quickly make their way to the scrap bin. In most cases the actual balun could easily be repaired but opening the case means destroying it completely.
Therefore we kept looking for a case that can be opened and closed with simple tools. We rejected solutions with rubber gaskets due to some disappointing results in the past. There are substantial temperature changes inside the housing. Dissipation in the balun causes excess pressure inside that partly leaks out and causes condensation and moisture after cooling off. As the water cannot escape it will cause severe problems after some time. To prevent condensation our cases can breathe. Any moisture in the case is quickly drained through numerous holes and the socket for the coax is mounted in a way that it will never be "under water", even in the worst case.
Furthermore, our novel balun case is versatile and easy to service. It can house a wide range of toroid sizes from 36mm O.D. to 60mm O.D. With its two slots two-stage baluns can easily be realized, for instance one toroid for impedance transformation and the other one for symmetry. The antenna wire can directly be hooked to the smaller toroids in the box. To make the connection weather-proof we recommend to solder the connections carefully and secure them with heat shrink tubing.
I'd like to thank the Schoelzel Verteko Company that helped me to develop the case and its necessary moulds for the PBT-GFK20 plastic. The costs of the necessary tools - fortunately pre-financed by the company - come close those of a mid-range car. As produced in relatively small quantities the case cannot be offered at a give-away price.
Hopefully, the Balun-Box will find wide acceptance and help a great number of hams to home-brew wire antennas of professional quality at reasonable costs.
Peter Bogner, DK1RP
P.S.: The Balun-Box is available for everybody, no matter if private customer, company or manufacturer…