Super clean Waterproof YouLoop Antenna outdoor Portable Passive Magnetic Loop Antenna for HF and VHF

This Ultra Portable waterproof Magnetic youLoop antenna can be Noise-Cancelling Passive especiall for signal frequency 10Khz-30Mhz.

Which has fix the noise problem,leverage the low-noise performance of our SDR receivers while being perfectly suitable for portable operation, also, it is waterproof IP67, for outdoor and indoor use.

This design has been improved than airspy youloop antenna.

Architecture

The You Loop Pro is a generalization of the Möbius loop where a balanced electric shield is used as the center of a multi-turn loop. The rest of the turns run inside the shield. This construction is electrically balanced for large wave wavelengths, ie. when Lambda is very large compared to the size of the antenna. This helps cancelling the electric noise at the lower bands, exactly where most of the electric noise energy is concentrated. To preserve this electric balance from alteration by the transmission line, a low loss miniature BALUN is used.

The following diagrams illustrate conceptual architecture described above. The more turns, the higher gain at the lower frequencies. Note that to preserve the electric balance, the number of turns increases by increments of two.

VHF Performance

Another interesting aspect of this two-turns coax build is its response in VHF. The same HF magnetic loop can be used in the FM and the 2m HAM bands with a slight change of its core principle: It’s now a folded dipole. Actually, the feed point of the folded dipole is on the top and the actual legs are composed of the coax ground. At this feed point, the signal is routed through the two coax legs to the wide-band, low-loss BALUN. The gray curved line depicts the signal path in VHF, which should be familiar for most. This makes the antenna perfectly usable for FM Broadcast, Aviation Band and 2m HAM Band; A very welcome option for portable VLF/LF/HF/VHF operation.

Further Improvements

In order to further improve the impedance matching and flatten the frequency response, a high impedance external pre-amplifier can be used near the antenna to present a constant output impedance to the receiver. We are working on a J-FET low-power pre-amplifier that could help DX’ers with extremely weak signals. This pre-amplifier also allows using a loop with a much smaller diameter, which improves the portability.

Specifications

• HF Response: 10kHz to 30 MHz

• VHF Response: up to 300 MHz

• Maximum Power: 250 mW

• Passive Design

• No Tuning required

•    Waterproof IP67
  

• Low-Loss Wide-Band BALUN with 0.28 dB loss type.

advantages:

•    Stunningly simple and straightforward electrical design.
  

• Hey it works. It’s an electrically small, no fuss, antenna.

• Functions perfectly fine with no counterpoise or equivalent connection to earth.

• It doesn’t require power although a decent feedpoint receiver or pre-amp will probably not hurt.

• Broadband by nature requiring no tuning components.

• Quite inexpensive. Superb price point.

• Works shockingly well indoors… ¯\_(“)_/¯

This thin antenna can be legitimately fastened to the back of wood furnishings, artwork, etc. to become a hidden low band receive antenna.

What is new for you loop Pro antenna:

- Affordable price than the competitors and with excellent waterproof function.

- The original youloop antenna relatively stiff coaxial cable isn’t quite rigid enough to hold a loop shape on its own, we have improve it and use faster loop bracket.

- The original youloop antenna A LOT of weight and twist strain exists on those SMA connectors and the PCB that holds them, we have added the strain to block the pressure.

- The novel SMA PCB top and bottom components appear to be stress points if the coaxial cables are not carefully arranged and fastened. The plastic housing certainly helps, we have fix it on the housing.

Considerations for any small loop antenna by John S. Huggins:

Ferrous materials should probably be kept well away.

As there is no escaping Chu-Wheeler limits, these antennas are very inefficient.

Thankfully inefficiency isn’t a show stopper for receiving purposes on the low bands.

Compatibility

• FOXWEY RTL SDR V3 Pro (Recommended)

• FOXWEY RTL SDR with two SMA antenna ports

•     FOXWEY MSI SDR compatible equally SDRplay RSP1A
  

• Any other SDR with MDS <= -140 dBm (There aren't that many)

Indoor YouLoop antenna reception tests

Robert Harvey (K2PI) ran his spotter system with his new Airspy YouLoop affixed to his basement wall inside his home. These 20m and 40m spot reports confirm good HF performance from the YouLoop.