Balun for - 9 bands dipole antenna. |
The mast I'm using is made from a crane-arm.
As you can see, it holds both TV, VHF and HF antennas,
all on the same mast, hence I had to insert a filter for when YL wants to watch TV, while I'm 'playing'.
I have to live with that the filters has a smaller range than the antenna, when the 50 ohm has to be observed. |
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In case you've got questions, feel free to contact me----
 oz6bu@qsl.net
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The balun is spun according to the specifications in ARRL handbook 'balanced to unbalanced 1:1, it consists of 15 winds bifillart spun, and covers the range 1.5-30 MHz.
I've used 3 shellac insulated copper threads,
each 55 cm. 1.8 mm - from an old
transformator, with small marks in each end of the threads, so I easily could identify which one to be connected.
The threads from the antenna are then connected,
on a yoke, and the balun gets connected.
This unit is then placed in a watersealed box, where you in the downward side mount
a socket for PL259 fast, where the coaxial
cable are to be connected.
When the box is done, you have to drill a 3 mm hole in the buttom, to prevent
condensated water to accumulate.
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