Youloop / Spytenna

n5rv

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ab3a

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I've used the YouLoop with my (modified) Airspy HF+. It's not a magical antenna, but it does work surprisingly well. I suspect most of the performance in this handy little antenna is due to the balanced nature of this loop and the binocular transformer that is used to isolate the antenna from the receiver and all of the computer noise associated with it.

I have seen similar isolation performance with a carefully amplified, shortened vertical antenna. (I used an AMRAD active antenna some years ago with a low noise, high dynamic range CP-666 JFET and a very carefully decoupled power supply and Bias T)

These days, FCC Part 15 is a sick joke. There is way too much RF junk being radiated from too many things that nobody tests for compliance. So the solution is to get away from it all. Isolate the antenna from the house, decouple it from your radio and your household environment, and hope that no egregiously strong RF sources are anywhere near you. The YouLoop does a pretty decent job of doing that. Try taking one to a park and see what it does.
 

n5rv

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The IC-R75 internal preamp works well with the loop. I've never been fond of external amps as they wide as a barn door so to speak.

It is interesting to tune to an empty frequency in the HF spectrum and turn the look back and forth to see the white noise level rise and lower. My computer monitor seems to be the biggest culprit, found that out from my earlier efforts to run down QRN generators in the house. The loop is a handy tool as well as a decent antenna for SW & MW.
 

n5rv

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I decided I needed a second loop. Now I have one for the RSP1A and the IC-R75. I've put another coat rack on order...

I do like this antennas performance for AM BCB (day and night) and for SWL in the evenings. As long you have some low noise amplification, you are good to go!

88752
 

ka3jjz

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You don't need an amp for radios that have really high sensitivity - most SDRs would qualify from what I've been reading on the reviews of this antenna. As noted, with a desktop like the R75 you may need some additional amplification. We have a few kits and other things that can help with that linked in our Loops wiki viz.


See section 2.3.1 - Loop amplfiers/kits. The W6LVP experimenter's kit looks like a possibility....Mike
 

n5rv

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Didn't say you need a low noise amplifier.... just some low noise amplification. The SDR and the R75 both have some additional gain to play with.
 

ka3jjz

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For those that are builders if you have the parts there's no reason why you can't build this yourself. There's a topic called 'Make Your Own Youloop' which has 3 articles - 2 of which have to do with stripping down some old VGA cables to get the materials for the binocular cores. It's found on section 2.2 of the above article...Mike
 

ka3jjz

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I have seen it used with a RTL-SDR v3; I would imagine this would also work with the Funcube....Mike
 

n5rv

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I'd like to someday have one hard mounted with a rotor. <dreaming of the day> :)
 
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