Damn! damn! damn! damn! damn!
The name of the new program is WHIP_1
It is NOT Unun_1
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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"Reg Edwards" wrote in message
...
At a transmitting station a vertical whip or random wire antenna is
occasionally used as an omnidirectional, multi-band receiving only antenna
..
SW listeners often use short or random wire antennas.
At LF and HF receiver input impedance is often very uncertain. It is
however
very uncritical.
Considering signal to noise ratio, especially for man-made noise, it is
seldom necessary to match antenna impedance to receiver impedance.
Signal+noise levels are high enough to be out of control of the operator
once adequate receiver gain is available - as it usually is.
This new program, UNUN_1, for a given signal field strength in the
vicinity
of the antenna, estimates receiver input volts versus antenna height or
length and frequency from 0.05 to 30 MHz.
The circuit consists of antenna whip or wire, plus 1:1 or 9:1 un-un
(balun),
plus coax cable, plus preselector, plus receiver with a choice of input
impedances. Antenna length extends up 1/3rd wavelenghts beyond which
behaviour ceases to change.
Assistance is given with ground connection loss resistance and estimation
of
field strength to be expected from various signal sources. It will be
appreciated results will be crude. But in the absence of any information
whatsover, any information on the behaviour of antennas versus length and
frequency will be useful to gurus, novices and short-wave listeners.
Download in a few seconds program UNUN_1 from website below and amuse
yourselves immediately. (It is the last in the website list)
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. .........