Airspy YouLoop

Discuss commercial and home made antennas.
EA8CHY
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Airspy YouLoop

Post by EA8CHY » Tue May 26, 2020 7:17 pm

Have you tried Airspy YouLoop with RTL-SDR V 3? How is it getting?

hotpaw2
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Re: Airspy YouLoop

Post by hotpaw2 » Thu May 28, 2020 8:55 pm

A YouLoop type antenna requires a receiver with a high-gain low-noise RF front end, such as an AirSpy HF+ Discovery. IIRC, an ordinary RTL-SDR in direct sampling mode doesn't have that much RF gain, and its 8-bit sampling creates a relatively high noise floor, so you might want to try using an LNA between the YouLoop and RTL-SDR to get decent signal levels.

rtlsdrblog
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Re: Airspy YouLoop

Post by rtlsdrblog » Fri May 29, 2020 9:09 am

You can receive with a V3 in direct sampling mode and with a YouLoop, but that SNR won't be as good as with a HF+ Discovery due to the specific requirements of a YouLoop.

To help you can use a HF amp, or wait until the official YouLoop preamp is released.

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bmh
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Re: Airspy YouLoop

Post by bmh » Fri May 29, 2020 8:40 pm

I'm using one and it's OK considering my limitations. I'm in an apartment on the top floor with no balcony and I can't put anything outside so I have tried various baluns and lengths of wire running along my ceiling in my living room (I'm not married fortunately) before getting the YouLoop and it does drop the noise floor but it's not a DX antenna and my line of sight might as well be outer space so I haven't noticed much of a reception difference if any. I'm looking forward to the preamp release so I can see if there's an improvement though my expectations aren't high with the YouLoop taped to my living room window. I don't blame the antenna for its performance because my conditions are far from ideal.

If your living conditions have antenna limitations similar to mine then I recommend the YouLoop. Otherwise if you have the capability to have an outside antenna that would be the far better choice.

EA8CHY
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Re: Airspy YouLoop

Post by EA8CHY » Fri Jun 12, 2020 6:23 pm

Thank you for your contributions. I am waiting for my Youloop, from China.

VE3EAR
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Re: Airspy YouLoop

Post by VE3EAR » Fri Jun 12, 2020 11:41 pm

I built my own YouLoop, but went with a different feed arrangement. Instead of using the binocular core transformer
to couple the antenna to the feed line, I opted for a current (aka choke) balun instead. It works much better.

Bruce, VE3EAR
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JEL
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Re: Airspy YouLoop

Post by JEL » Sat Jun 20, 2020 9:53 am

When I follow the red wire from the connector-plug side (The red center-pin wire) I can only count 1 loop in the most direct electrical connection.
(Through the green connection you get a single electrical loop and through the black connection you get two electrical loops)

So what is the benefit of the Youloop's apparent twin-loop design? (The center-pin to shield cross-over at the 'top' of the loop)

I built a multi-loop myself, which has only 1 single electrical connection.

Should I get any benefits by short-circuiting the 1st loop like it is done on the Youloop?

The loop I built myself has 6 turns and one single electrical path (Current has to go through all the loop-turns)
The youloop has 2 turns but 2 electrical paths (Current can skip one loop-turn, but is also still electrically connected through both loop-turns)

I can't wrap my head around this design (I'm not an antenna-designer, so my knowledge is limited here, but I'm trying to understand it)

If current chooses the most direct path, then aren't the 'extra' loop rendered useless? (Or do this extra loop exhibit some specific noise-reduction which is missing in a true multi-loop design (An electrically true multi-loop. IE one where the current only has one path)

What am I missing here?

VE3EAR
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Re: Airspy YouLoop

Post by VE3EAR » Sat Jun 20, 2020 1:21 pm

So what is the benefit of the Youloop's apparent twin-loop design?
That's a very good question. You're correct in thinking that the shortest path, as far as DC is concerned, only has one turn in the loop proper. Perhaps the RF "sees" a different path, and takes advantage of both turns, is the only possible answer that I can think of.

73, Bruce, VE3EAR

VE3EAR
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Re: Airspy YouLoop

Post by VE3EAR » Sun Jun 21, 2020 4:35 pm

Perhaps the RF "sees" a different path
I couldn't get your observation off my mind yesterday, and I pondered what to try to resolve this issue. Since my area of interest is receiving the AM broadcast band, along with the amateur 80M and 40M bands, it seemed to me that I would need more turns than the four in the original construction article. I removed the "current/choke balun" windings and put
on two separate windings of ten turns each. This solved the problem of the shield ground wire shorting out one turn of
the loop as you had noticed. It worked not bad on 40M, but not so well on 80M and the AM broadcast band.

This morning I put the antenna back on the bench and re-wound the transformer yet again. This time I put 9 turns on the antenna side and 18 turns on the radio side. This gives a step-up of 1:2 for voltage and 1:4 for impedance, which in theory should provide for a better match between the loop and the radio. I'll have to wait until this evening to do a listening test with the third iteration of the NCPL. In the end, I think I'll have had more pleasure from doing all of these experiments than
I will have when actually using it!

JEL
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Re: Airspy YouLoop

Post by JEL » Tue Jun 23, 2020 12:06 pm

Hahaha nice, tinkering is a lot of fun :)

I do hope you have fun using it too though, but I couldn't help but laugh when I read your comment :)

My own skills in antenna-design are very limited, so I'm not sure if a DC short-circuit is necessarily a bad thing.

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