Tagged: antenna

The SWLing Post Reviews the YouLoop Passive Loop Antenna

Over on the SWLing (Short Wave Listening) Post blog Thomas has just uploaded his review of the YouLoop in a post titled "The Airspy Youloop is a freaking brilliant passive loop antenna". If you weren't aware, we are currently selling this loop in our store for US$34.95 incl. free worldwide shipping to most countries. Sales are currently in pre-order as our first batch of units ordered sold out within a day, but we're soon going to receive the second batch in the next few days. 

Thomas is a seasoned shortwave listener who has used many antennas, and in the review he notes that he is extremely impressed with the performance. In his review he tests the antenna in a location that is swimming with RFI and places the loop in the middle of a bedroom. Although the situation is not ideal, Thomas was surprised at the number of signals he was able to receive.

To work properly the YouLoop requires a low noise figure radio like the recommended Airspy HF+ discovery, but Thomas notes that he's also had excellent success with the SDRplay RSPdx running in HDR mode.

YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF
YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF

YouLoop Batch 2 Available for Pre-Order: Estimated Shipping in One Week

A few days ago we posted about our release of the first batch of YouLoop passive HF/VHF loop antenna kits. We underestimated the demand and sold out of kits in less than a day! We now have a second batch currently being manufactured and it should be ready to ship out in about a week from now (late March/early April).

You can currently pre-order this item from our store, and we will ship it out as soon as the stock hits the shelves on our warehouse. For this product we are focusing on non-US customers and US customers can purchase locally from airspy.us. Though we will still fulfill US orders if you want to order from us instead.

If you are interested in further information, search YouLoop on Twitter to see a bunch of new tweets about people talking about and demonstrating this antenna design.

YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF
YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF

Techminds Reviews a HF RX SWL Antenna for Small Spaces and Apartments

Over on his YouTube channel TechMinds has uploaded a video reviewing the X1-HF 1 - 50 MHz Trapped Coil Receiving antenna from Moonraker.eu which goes for £69.95. This is a small electrically short antenna for HF reception which is easy to setup and install, requiring no radials. However, like all short HF antennas it is a compromise.

In the review he uses an SDRplay RSP2 SDR to test HF reception with the antenna. Later in the video he also tests it outside the advertised 1 - 50 MHz range. He concludes that the antenna works very well for it's small size.

HF RX SWL Antenna For Small Spaces And Apartments RTL SDR

New Product in Store: RTL-SDR Blog Magnetic Whip Antenna Set (Great for KerberosSDR Direction Finding)

We've recently released a new Magnetic Whip Antenna Set in our store. The set consists of a heavy duty magnetic mount antenna base with 2M RG59, a 9.5cm fixed whip antenna (usable from 400 MHz to 2 GHz+), and a 17cm to 1m telescopic whip (usable from 100 MHz - 400 MHz).

Click Here to Visit our Store

The antenna set costs US$14.95 each with free shipping. And if you buy four sets you will receive a 15% discount. Currently available to ship worldwide right now from our warehouse in China, and they will be on Amazon in 2-3 weeks.

One application of our KerberosSDR 4-Tuner Coherent RTL-SDR is radio direction finding. This requires four quality omni-directional antennas. We were disappointed to find that there were no high quality magnetic whip antennas available on the market for a low price that we could use with KerberosSDR so we made our own.

The magnetic base is designed carefully with conductive metal that is properly connected to the shield of the coax cable. Most cheap antenna bases just leave the shield connection floating and this causes insufficient coupling to the underlying ground plane resulting in poor performance and poor results when it comes to direction finding and reception.

We've tested this set with KerberosSDR and it is known to work well. The antenna can also of course be used for any other receiving purpose if you prefer to use a whip antenna over our multipurpose dipole antenna set.

In the first two images in the image slider below you can see a comparison between a black base that is not properly bonded to the coax shield, vs the RTL-SDR Blog silver base which is correctly bonded to the coax shield. Both tests used the 9.5cm whip antenna. You can see that the RTL-SDR Blog silver base provides a much lower noise floor and higher signal SNR due to the better ground plane. Also we note that when placing the antenna bases on a metallic surface to create a larger ground plane, the black base showed no further improvement, whereas the RTL-SDR Blog silver base did.

The final three images in the slider show the SWR plots of the two whips on the base. We can see that the 9.5cm whip provides an SWR of less than six below 412 MHz. The telescopic whip can be adjusted to provide better SWR for lower frequencies.

RTL-SDR Blog Antenna Base (Coax shield properly connected to base)
Generic Black Antenna Base (Coax shield not connected to base)
9.5cm Whip SWR Plot
Telescopic Whip Collapsed SWR Plot
Telescopic Whip Fully Expanded SWR Plot
RTL-SDR Blog Antenna Base (Coax shield properly connected to base) Generic Black Antenna Base (Coax shield not connected to base) 9.5cm Whip SWR Plot Telescopic Whip Collapsed SWR Plot Telescopic Whip Fully Expanded SWR Plot

The SWLing Post Reviews the YouLoop Passive Loop Antenna

Over on the SWLing (Short Wave Listening) Post blog Thomas has just uploaded his review of the YouLoop in a post titled "The Airspy Youloop is a freaking brilliant passive loop antenna". If you weren't aware, we are currently selling this loop in our store for US$34.95 incl. free worldwide shipping to most countries. Sales are currently in pre-order as our first batch of units ordered sold out within a day, but we're soon going to receive the second batch in the next few days. 

Thomas is a seasoned shortwave listener who has used many antennas, and in the review he notes that he is extremely impressed with the performance. In his review he tests the antenna in a location that is swimming with RFI and places the loop in the middle of a bedroom. Although the situation is not ideal, Thomas was surprised at the number of signals he was able to receive.

To work properly the YouLoop requires a low noise figure radio like the recommended Airspy HF+ discovery, but Thomas notes that he's also had excellent success with the SDRplay RSPdx running in HDR mode.

YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF
YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF

YouLoop Batch 2 Available for Pre-Order: Estimated Shipping in One Week

A few days ago we posted about our release of the first batch of YouLoop passive HF/VHF loop antenna kits. We underestimated the demand and sold out of kits in less than a day! We now have a second batch currently being manufactured and it should be ready to ship out in about a week from now (late March/early April).

You can currently pre-order this item from our store, and we will ship it out as soon as the stock hits the shelves on our warehouse. For this product we are focusing on non-US customers and US customers can purchase locally from airspy.us. Though we will still fulfill US orders if you want to order from us instead.

If you are interested in further information, search YouLoop on Twitter to see a bunch of new tweets about people talking about and demonstrating this antenna design.

YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF
YouLoop Portable Passive Magnetic Loop Antenna for HF and VHF

Techminds Reviews a HF RX SWL Antenna for Small Spaces and Apartments

Over on his YouTube channel TechMinds has uploaded a video reviewing the X1-HF 1 - 50 MHz Trapped Coil Receiving antenna from Moonraker.eu which goes for £69.95. This is a small electrically short antenna for HF reception which is easy to setup and install, requiring no radials. However, like all short HF antennas it is a compromise.

In the review he uses an SDRplay RSP2 SDR to test HF reception with the antenna. Later in the video he also tests it outside the advertised 1 - 50 MHz range. He concludes that the antenna works very well for it's small size.

HF RX SWL Antenna For Small Spaces And Apartments RTL SDR

New Product in Store: RTL-SDR Blog Magnetic Whip Antenna Set (Great for KerberosSDR Direction Finding)

We've recently released a new Magnetic Whip Antenna Set in our store. The set consists of a heavy duty magnetic mount antenna base with 2M RG59, a 9.5cm fixed whip antenna (usable from 400 MHz to 2 GHz+), and a 17cm to 1m telescopic whip (usable from 100 MHz - 400 MHz).

Click Here to Visit our Store

The antenna set costs US$14.95 each with free shipping. And if you buy four sets you will receive a 15% discount. Currently available to ship worldwide right now from our warehouse in China, and they will be on Amazon in 2-3 weeks.

One application of our KerberosSDR 4-Tuner Coherent RTL-SDR is radio direction finding. This requires four quality omni-directional antennas. We were disappointed to find that there were no high quality magnetic whip antennas available on the market for a low price that we could use with KerberosSDR so we made our own.

The magnetic base is designed carefully with conductive metal that is properly connected to the shield of the coax cable. Most cheap antenna bases just leave the shield connection floating and this causes insufficient coupling to the underlying ground plane resulting in poor performance and poor results when it comes to direction finding and reception.

We've tested this set with KerberosSDR and it is known to work well. The antenna can also of course be used for any other receiving purpose if you prefer to use a whip antenna over our multipurpose dipole antenna set.

In the first two images in the image slider below you can see a comparison between a black base that is not properly bonded to the coax shield, vs the RTL-SDR Blog silver base which is correctly bonded to the coax shield. Both tests used the 9.5cm whip antenna. You can see that the RTL-SDR Blog silver base provides a much lower noise floor and higher signal SNR due to the better ground plane. Also we note that when placing the antenna bases on a metallic surface to create a larger ground plane, the black base showed no further improvement, whereas the RTL-SDR Blog silver base did.

The final three images in the slider show the SWR plots of the two whips on the base. We can see that the 9.5cm whip provides an SWR of less than six below 412 MHz. The telescopic whip can be adjusted to provide better SWR for lower frequencies.

RTL-SDR Blog Antenna Base (Coax shield properly connected to base)
Generic Black Antenna Base (Coax shield not connected to base)
9.5cm Whip SWR Plot
Telescopic Whip Collapsed SWR Plot
Telescopic Whip Fully Expanded SWR Plot
RTL-SDR Blog Antenna Base (Coax shield properly connected to base) Generic Black Antenna Base (Coax shield not connected to base) 9.5cm Whip SWR Plot Telescopic Whip Collapsed SWR Plot Telescopic Whip Fully Expanded SWR Plot

Building a DIY 2.4 GHz Helical Feed for the QO-100/Es’Hail-2 Satellite

Over on his YouTube channel Adam 9A4QV has uploaded a short video that demonstrates his 2.4 GHz homemade helical feed designed to be used with a reflector (prime feed satellite dish) for QO-100/Es'Hail-2 satellite reception. The antenna is made from an old can, 2-turns of copper wire, and a plastic insulator to hold the turns in place. The two turns are wound in left hand circular polarization (LHCP), because when used with a satellite dish reflector it will result in right hand circular polarization (RHCP), which is the polarization QO-100 uses.

One of the most important parts of the video is when Adam shows how he matches the antenna to 50 Ohms. He notes that without matching the antenna won't work properly, and the return loss will be about 8 dB or even less, resulting in poor performance. With matching he obtains 30 dB return loss.

Helical feed for the 2.4 GHz QO-100 satellite

Building a Carbon Fibre Dual Band Yagi Antenna for Amateur Radio Satellites with 3D Printed Parts for 20€

Back in early 2017 we posted about Manuel's (aka DO5TY / Tysonpower) design for a single band 140 MHz 3D printed carbon fibre Yagi antenna. Today he's submitted a new video about creating a dual band 3D printed carbon fibre cross Yagi antenna for only 20€. Note that the video is narrated in German, but there are English subtitles. He's also uploaded an English text tutorial to his blog, which includes links to the 3D printer STL files.

The antenna is designed to be a low cost replacement for the commonly used Arrow dual band 2m/70cm antenna which is designed for receiving and transmitting to amateur radio satellites. Many amateur radio satellites have an uplink frequency set at around 145 MHz, and a downlink frequency around 435 MHz (and some satellites have the frequencies reversed). So a dual band Yagi is ideal for these satellites. Manuel writes that with his 5W Baofeng handheld he's already made several successful contacts with his new antenna.

Manuel's antenna consists of several 3D printed joints, with a carbon fibre rod used as the main boom. Aluminum rods make up the receiving and transmitting elements. The video also discusses impedance matching and how he uses a diplexor so that there is only one connection required to the radio. The advantage of his antenna over the Arrow is that it is significantly cheaper, and also much lighter in weight.

[EN subs]Carbon Arrow Yagi Antenne - leichte Dual Band Yagi für 20€ bauen

Designing and Testing a PCB Wideband Spiral Antenna

Back in January we posted about a Vivaldi antenna project by "hexandflex". In that project he showed how he designed and manufactured the Vivaldi. A Vivaldi antenna is wideband and directional and the design works well for frequencies above 800 MHz, but becomes too physically large to handle for lower frequencies like 400 MHz. In his latest project, hexandflex has designed a PCB based spiral antenna to cover these lower frequencies.

Hexandflex's post is split into three parts. The first post introduces us to his motivation and talks about what spiral antennas are. The second post discusses the modelling and simulation of the antenna with OpenEMS. OpenEMS is a free front end for MATLAB or Octave which allows you to simulate antenna parameters such as impedance and radiation pattern. Finally in the third post the real world parameters of the antenna are determined in an anechoic chamber owned by Antenna Test Lab, a professional antenna testing agency.

Hexandflex is currently selling his spiral antennas over on Tindie. There are two versions, one smaller one costing $32 designed for 800 MHz+ and a larger one costing $42 designed for 300 MHz+. Both come with suction cups that allow for easy window mounting.

The 800 MHz+ and 300 MHz+ spiral antennas by Hexandflex
The 800 MHz+ and 300 MHz+ spiral antennas by Hexandflex

Constructing a 3D Printed Wideband 900 MHz to 11 GHz Antenna

Thanks to Professor John Jackson of JR Magnetics for writing in and sharing his design for a 3D printed wideband antenna designed for 50 Ohm 900 MHz to 11 GHz operation.

John required a wideband antenna that could cover the cellphone bands, WiFi, Bluetooth up to 6 GHz and the new USB band from 5 GHz to 10 GHz all in a single antenna installation. He also needed the impedance to be as flat as possible to reduce signal pulse distortion. First he looked into classic discone and sphere antenna designs, but found that while a sphere had the required bandwidth, it did not have the desired impedance characteristics, and a discone had the desired impedance characteristics, but not the ultra wide bandwidth required.

To get around this John combines the sphere and discone designs together to create a sort of icecream with cone looking shape. This results in the ultra wide bandwidth required, and a relatively flat SWR that stays below 2.

The design is easily reproducible by anyone with a metal 3D printer. The antenna's top hemisphere and cone are printed in brass, whilst the radome and supporting structure are printed in plastic.

We have uploaded John's original document here (pdf warning), and display some of the images below. The full build instructions can be found on his website, and John is also selling the 3D printed parts via Shapeways.