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Shortened End Fed Calculations Help

I read that link before and thought the part about signals being reflected off into space was lame...

Tune an antenna to resonance with a tuner and then simply bypass that tuner and the results are far less dramatic....

I agree with both comments, however, the issue is about non resonant antennas.
 
If it required a tuner to make it resonant then it would have been a non resonant antenna would it not? Why would you use a tuner on an already resonant antenna?

I don't quite know how to respond to that and not sound like a smart azz,...
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the tuner doesn't tune the antenna, it is still non resonant....
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I don't quite know how to respond to that and not sound like a smart azz,...
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the tuner doesn't tune the antenna, it is still non

Agreed. And are we not talking about non resonant antennas ? Are we not are talking using a tuner to "tune" (note the quotation marks) the antenna? I realize that a tuner really acts as an impedance transformer for everything connected to it and does not actually tune anything. I always did prefer the term matcher over tuner.
 
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yes, the "tuner" (IMO) just confusing the real issue.

We are talking about the SNR of a resonant antenna Vs the SNR of a non resonant antenna; both operated at the same time "listening" to the same input signals and same "white" noise.

I believe that the resonant antenna will have the higher SNR.

this is based on operations using a screwdriver antenna and listening to on going QSO's while tuning the antenna,

QSO's that were so buried in the white noise and barely understandable, were often 59 after tuning, the "white noise" remained the same, but, the audio signal was much louder.
 
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I just re-read this and noticed the 3.9 MHz target.

that is doable
32 feet of wire then 44 uH coil, then 32 feet wire should be about 3.6 MHz
31 1/2 feet of wire then 42 uH coil then 31 1/2 feet should be about 3.8 MHz

so, 31 feet even should be about 3.9 MHz +/- YMMV

the coil should be 20 turns 14 ga wire on a 4 1/2 od pvc tube for 44 uH
.... if ya really wanna be picky, make it 19 turns,... about 40 uH

that 62 foot overall should fit nicely in the 60 foot dimension with a little sag.

So I'm curious, what is the math and/or formula to determine what the uH of the coil would be for a set of parameters? I've seen some references but never been able to unravel the Frequency/Length and uH number.
 
yes, the "tuner" (IMO) just confusing the real issue.

We are talking about the SNR of a resonant antenna Vs the SNR of a non resonant antenna; both operated at the same time "listening" to the same input signals and same "white" noise.

Then I must have missed something then because I could swear we were talking about a single antenna and simply switching a tuner inline to match the impedance to a receiver in the case of SWL. :confused:
 
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We were. I asked the question CK. Wasn't trying to hijack TBA02's thread. Just was more curious as to how antennas orientation like in an L pattern or part horz and part vert, would work. This isn't my post so I would say back on topic, which was about shortened end fed calculations. I thank you very much for taking the time to answer my questions though and it will all be put to good use!! Reason for the SWL antenna is due to me not having my ticket, but having a radio that can be used on many other bands. Again, thanks to all that helped answer my questions. You gents know who you are!!! Guess it's time I picked up a few books on antennas and start reading!!! Again, thx to all.
73 and God Bless.
 
I meant to jump in with a mention of the inverted L. It tends to have more vertical radiation than horizontal and actually performs more like a top loaded vertical.There is some horizontal radiation however. I used to have one that was about 35 feet vertical and 70 feet horizontal. Worked ZS6CCY in South Africa on 80m with 100 watts and it was two hour past his local sunrise. It was actually a very good antenna for it's size and configuration.
 
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