Tom,
The technology you are talking about is called NFC, Near
Field Communications. It uses the magnetic (H) part of the
RF radiation -- near field -- but it does have an electric
component, although that is quite weak. The antenna, both
in the lock and in the card, is usually a multi-turn loop.
The lock transmits power which is picked up by the card's
antenna and is used for powering the chip and
communications. Most systems use a rolling code, which
provides security and protection against interference.
It is not likely that your transmissions (even on 14 MHz)
will trick the locks to open. It is more likely that
during transmissions locks may not open, or open
sluggishly. You may also get some noise on 20 meters from
the side-bands of 13.56 MHz signal.
NFC readers will in the near future be used for point of
sale card payments (contact-less cards) and will be
installed at millions of merchant locations. They may turn
into another source of noise on HF.
73, George
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Topband Reflector
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