receive only ferrite antenna
dansawyeror wrote in
:
Owen,
Thank you. The environment is medium density residential. I am
listening to a net regularly on 3970kc. I have limited space and
cannot rig a half wave dipole and am looking for alternatives.
Frequently a station close by picks up stations I cannot hear. I am
looking for small space alternatives. Given that that station is in
the same 'cosmic' noise environment what characteristics create a
superior s/n ratio?
If you looked at the reference material I gave you, you will see that you
might expect the ambient noise in a residential environment to develop
about -83dBm in a 2kHz wide rx with a lossless antenna.
If your receiver noise floor was say -136dBm (Noise Figure about 5dB, a
state of the art HF receiver), and you wanted a 6dB margin to restrict
degradation of the "off-air" S/N to 1dB, then your antenna needs to have
gain of at least ( -136 - -83 + 6 )dBi, or -47dBi. That is not very
difficult to achieve, even with a ferrite loop antenna.
Owen
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