PPRuNe Forums - View Single Post - How does a short HF antenna on an Airbus transmit/receive such long wavelengths?
Old 19th Aug 2017, 12:17
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Teapot Rebellion
 
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How does a short HF antenna on an Airbus transmit/receive such long wavelengths?

What type of witchcraft are engineers using for a very short antenna in the leading edge of a tail fin, to be able to receive and transmit on HF?



When doing my ATPL studies many years ago, the information was rather superficial on HF equipment.

Let's say the frequency we are tuned to is 9000 khz or 9 mhz. That equates roughly to a wavelength of just over 30 metres.
Even if the antenna were a quarter wavelength long, it would still need to be over 8 metres in length - yet the antenna is much shorter than that.

So how is this trickery done? Are they using the entire tail fin for radiating/receiving? In which case the "antenna" referenced in my FCOM isn't really an antenna at all, it's just a tuning unit.
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