lørdag 12. mai 2018

Loss in 1:49 EFHW baluns

As far that I'm aware of, no one has presented any good measurement of the loss in the 1:49 balun, so here it is:
As can be seen, the loss is lowest in the 17 m band, with about 1 dB loss. The loss is highest on 80 m with about 1.7 dB loss. Adding capacitors does not affect loss very much below 17 m, but increases loss slightly above 17 m. (Rising the loss from about 1.4 dB to about 1.6 dB on 10 m.)
Measured with miniVNATiny, sweep from 3 MHz to 30 MHz.
160 m was omitted because of the high losses on that band.
The transmission loss was measured with 2 baluns connected back-to-back, due of this, the loss in the graphs must be divided by 2.
For those, not familiar with desiBels, this means that with 100 watt into the balun, you will have about 79 watt out of the balun on 17 m (which is the band with the lowest loss) and about 67 watt out of the balun on 80 m (which is the band with the highest loss).


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