"Robert Jeffares" wrote in
:
baluns are transformers and the impedance ratio is related to the
turns ratio.
If you have a dipole antenna the centre feed point is about 75 ohms
and if you have 75 ohm coax the balun needs to be 1 : 1 .
If you have an end fed antenna the feed point can be anything from 600
- 1000 ohms so a 4:1 to 8:1 ratio matches the coax.
Bit of experimentation.
use the one that works best.
Feed point impedance depends on the frequency, so measurements, while
possible, tell you an exact answer to a question where close enough is
an OK answer.
I have Alpha Delta DX Ultra and it's a dipole. There is an output for the
coax, so I was wondering if such antenna needs a balun or this is
neglegable and connecting 50 ohm coax will do the job.
|