Category Archives: Antennas

Tony performs a quick LNA4ALL test

Many thanks to SWLing Post contributor, Tony Roper, who shares the following guest post which originally appeared on his blog, Planes and Stuff:


Quick LNA4ALL test

by Tony Roper

Despite the best efforts of the Royal Mail service, I have been able to get my hands on a Low Noise Amplifier created by Adam at LNA4ALL. The Royal Mail showed just how useless it is, when the parcel arrived here in the UK in just 11 hours from Croatia on February the 14th, but then not getting delivered to me until March the 14th – yes, one month! There is no surprise that courier companies such as DPD and Hermes are getting more business than the Royal Mail – they are bloody useless.

Anyway, the reason for the purchase is for a later review on an AIS dongle that I will be testing, but which has unfortunately been possibly damaged before getting to me.

So, as I had some time to spare I thought I’d run a quick test on how the LNA performs against the claims that is shown on the LNA4ALL website. For the test I used a quickly built 12v to 5v PSU that was connected to a Maplin bench PSU and also a Rigol DP711 Linear DC PSU where I could ensure a precise power input. As it was, it was good that I used the DP711 because my quick PSU was only chucking out 1.2v at connection to the LNA4ALL, despite an unconnected output of 5v – some work needed there I think.

Despite this lower power the LNA4ALL still worked with just the 1.2v input, though the results where not as good.

Other equipment used were a Rigol DSG815 Signal Generator and a Rigol DSA1030 Spectrum Analyser (no longer available), along with various Mini-Circuits shielded test cables. The Rigol equipment I purchased from Telonic Instruments Ltd last year.

Below then is a table that contains all the relevant data. As you’ll see the Gain claim is pretty much spot on with some being over. Just a couple of frequencies are below that which is claimed, especially at 28 MHz.

LNA4ALL Frequency data

A couple of things to note.

Firstly, somehow I managed to miss testing 1296 MHz. I obviously didn’t put it in the table in Excel before I started ? Also, the DSG815 only goes up to 1.5 GHz so I couldn’t test above that.

Secondly I ran a test for the AIS centre frequency of 162 MHz, for which there was no comparison to the LNA4ALL data. A gain of over 24dB though shows that the LNA would be perfect for those of you with AIS receivers that may want to get better reception. To prove the theory I compared the LNA reception against data without it connected to the NASA Engine AIS receiver that I currently use. In ShipPlotter I average a max range of around 15nm without the LNA, but with it connected this increased to around 22nm. The number of messages received also tripled as it was able to dig out the weaker signals.

The NASA Engine isn’t a bad receiver, but it is a frequency hopper rather than a dual monitor, and so it changes between the two AIS frequencies every 30 seconds (161.975 MHz and 162.025 MHz). I suspect a dual monitor would give better message numbers and range.

Below is a graph made using the excellent software by Neal Arundale – NMEA AIS Router. As you can see the message numbers (or sentences) for over an hour are pretty good – well, it is a vast improvement on what I used to get with my current “temporary” set-up, with 419 messages received in an hour. The software is available at his website, for free, along with various other programs that you can use with AIS. If you’d rather not use ShipPlotter he has created his own AIS Decoder which can be linked into Google Earth and such like. Visit his website for more information.

My antenna isn’t exactly top-notch. It is at a height of just 4 metres AGL in the extension loft, and it is made from galvanised steel angle bead used by plasterers to strengthen corners prior to skimming – this I cut down as a dipole for a target of 162 MHz. As usual with my trimming of antennas, I cut just too much off and ended up with it cut to 161.167 MHz. It gives a VSWR of 1.018 and Return loss of 40.82dB, with 162 MHz being approx. 30dB Return loss which equates to 1.075 VSWR – that will do.

Also, as I live right on the coast, about 50 metres from the sea, I’m practically at sea level, which doesn’t help much with range and signal reception either. Despite this the antenna produces great results, though it is just temporary until I can get a new homebuild up on the roof.

VSWR reading for the homebrew loft AIS Antenna

The LNA4ALL retails at various prices depending on what option you go for. I went for the aluminium box version so it was around £54 including the delivery. I had looked at a Mini-circuits equivalent, and when it looked like the LNA4ALL was lost I did actually order one. But this was nearly twice the price, and seeing as the LNA4ALL contains many components from Mini-Circuit I doubt it is any different really.

All in all the LNA4ALL is all you need to boost your weak signals – couldn’t get any more all’s in ?.


Many thanks for sharing your quick test of the LNA4ALL, Tony! Post Readers: if you’d like to read more of Tony’s work, check out his blog, Planes and Stuff.

Daytime DX: Gary compares Terk Advantage with homebrew FSL Loop

Many thanks to SWLing Post contributor, Gary DeBock, who shares the following:

Daytime DX Shootout– a new-design 4.7 inch FSL antenna ($62 construction cost) goes up against the Terk Advantage AM commercial loop ($58 on eBay) in the daytime DX reception of 650-CISL (10 kW at 160 miles, in Vancouver, B.C.).

The first 20 seconds are on the Terk Advantage, and the final 24 seconds are on the new 4.7 inch FSL (using 27 of the commonly available 62mm Russian surplus ferrite bars).

Signal strength is roughly equal, but the FSL’s lower noise advantage gives it the edge.

Click here to download MP3.

Thank you for sharing this comparison, Gary. You’re right: the FSL provides lower noise and a more stable signal to boot. Still, I’m impressed the Terk was able to compete! In terms of commercially-produced loops, the Terk Advantage is certainly a good one.

Gary’s mediumwave DX FSL antenna phasing experiment

Many thanks to SWling Post contributor, Gary DeBock, who shares the following note about his latest FSL antenna experiment:

Medium wave DX FSL antenna phasing experiment– 1593-CNR1 (Changzhou, China, in Mandarin) boosted up to strong (S9) peaks by two 5 inch “Frequent Flyer” FSL’s at 1435 UTC on February 25th in my frozen back yard in Puyallup.

Unlike other high gain MW antennas, the FSL’s can provide cumulative gain at very close inductive coupling ranges.

Click here to download and play MP3 recording.

Amazing, Gary!  Thank you for sharing this excellent bit of DX!

Click here to read more about Gary’s FSL antennas.

An EDC Bag for the Classic Sony ICF-SW100 Receiver

In a 2014 article, this site’s administrator Thomas Witherspoon introduced readers to the CIA’s Survival Kit which is housed in a superbly sturdy waistpack, the Maxpedition M-2. Thomas observed that the M-2 pouch is perfectly suited to holding the diminutive Sony ICF-SW100 receiver.

I was intrigued by that possibility, but only recently tried to combine the two after I resurrected another ICF-SW100 that fell silent to the chronic broken ribbon cable problem. Indeed, the radio is a perfect fit and the M-2 is impressively solid and well designed. I was not aware of the Maxpedition firm prior to learning of the M-2 bag, but I see in various forums they are a major player in well-made gear for the survivalist and outdoor enthusiast crowds. The M-2 is a very popular item, and one or more of the four available colors are sometimes out of stock at the manufacturer. Fortunately there are many sellers on Amazon and Ebay who have these waistpacks available.

What is EDC you may ask? It refers to “Every Day Carry”, the essentials that an individual deems necessary for their lifestyle or a particular activity. For me, an EDC bag is taken along on hikes or other outings to the countryside and typically contains a compact shortwave radio and related accessories. It’s always fun to stop for lunch or a break in a remote location and be able to search for interesting stations whenever the mood strikes.

This photo shows what I’m able to carry in the Maxpedition M-2 bag; a coffee mug is shown for size comparison. Contents of the “kit” include:

  • The Sony ICF-SW100 receiver
  • Zero Audio Carbo Tenore In-Ear Monitors & soft pouch
  • Sony AN-71 reel-up antenna
  • Panasonic RR-XS400 Digital Voice Recorder
  • Short 3.5mm male-to-male stereo audio patch cable
  • Two extra AA batteries for the Sony receiver
  • An extra AAA battery for the Panasonic Digital Voice Recorder

A few comments on the contents. The Zero Audio Carbo Tenore In-Ear Monitors (IEMs) provide excellent audio quality for their price. They are among a handful of IEMs regularly recommended by budget-minded audiophiles on the popular Head-fi.org site. I like these IEMs not only for the audio quality, but also their small size (in the cloth bag) which barely fits into the M-2’s main compartment along with the ICF-SW100. Larger earbuds or IEMs might not fit the M-2 without being mangled by the hefty YKK zippers. One caution: the similar Carbo Basso model by Zero Audio is deemed by many to be overly heavy on the bass frequencies. I find the Carbo Tenore to be more than sufficient for bass heavy genres like Electronica.

The Panasonic RR-XS400 digital voice recorder has been out of production a few years, but is a highly capable and compact recorder. It contains a hidden USB plug for charging and data transfer, has a fully featured and backlit LCD display, built-in stereo microphones, switchable LINE/MIC inputs, and other useful features. In excellent used condition the RR-XS400 is worth about $50 USD in 2017, despite some Amazon sellers trying to move them at the original $280 price.

The extra AAA battery for the recorder slips into the front pouch of the M-2 bag along with the Sony AN-71 antenna. The additional AA batteries for the radio, however, are held in the two “pen loops” on the left and right of the M-2. Despite these loops being open-bottomed tubes, the fit is tight enough to hold the batteries securely.

Like every portion of the Maxpedition M-2 bag, the belt loop is proportioned perfectly and sewn with precision. With the Sony ICF-SW100 EDC “kit” secured to my belt on a hike, I’m assured of quick access to a DXing opportunity, such as when hiking the Naches Loop Trail near beautiful Mt. Rainier:

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

The W6LVP magnetic loop antenna

Many thanks to SWLing Post contributor, Troy Riedel, who asks:

Just curious if you or anyone you know have any experience with Magnetic Loops from W6LVP? […]Here’s his eBay page – 458 feedbacks and 100%.

Thank, Troy! I’ve never used the W6LVP loop, but the price–in comparison with other wideband mag loop receive antennas–is very attractive.

W6LVP currently offers two models of loop antennas:

Here’s the product description of the Mag Loop with Power Inserter from the W6LVP website (where orders can also be made–pricing identical to eBay):

The Wellbrook Model ALA1530LN-2 and DX Engineering (Pixel/Inlogis) Model RF PRO-1B magnetic loops are both good amplified receive antennas.  However, they are both expensive.  Shipping the Wellbrook antenna from the UK to the US adds another $100.

Extensive side-by-side testing of the Wellbrook, DX Engineering, and W6LVP receive loops was compiled using simultaneous WSPR signal-to-noise reception reports on all LF, MF, and HF amateur bands.  In addition, extensive laboratory bench tests measuring gain, signal-to-noise ratio, and IMD were also performed.  Signal-to-noise ratio is important to pull weak signals out of the noise and IMD is important to reject distortion caused by nearby strong transmitters such as AM broadcast stations.  In both test regimens, all three antennas performed very well and without significant difference.

The antenna version listed here includes a power inserter for use with receivers or with transceivers that have a separate receive antenna input.  If your rig doesn’t have a receive antenna input, check out my antenna with a transmit/receive switch.

If you live in the shadow of one or more high-power AM broadcast transmitters, contact me about a special version just for you.  Please contact me at lplummer@vcnet.com.

W6LVP amplified receive-only magnetic loop antenna (boy is that mouthful):

  • The W6LVP mag loop is a complete receive antenna system delivering top-of-the-line performance to amateur radio operators and SWLs – particularly for those with space and/or budget limitations.  It is a great complement to vertical or wire transmit antennas.   You have a knob to turn up the power but don’t have one to turn up the received S/N.
  • Ten foot circumference (approximately 1 meter diameter) loop.  Small size yields a natural stealth for HOA challenges.  The loop is rigid enough to maintain its shape but flexible for portable transport or attic installation.
  • Includes a low-noise, broadband amplifier covering 2200 (135 kHz)  through 10 meters (30 MHz) with no tuning or adjustment.  Perfect match for continuous tuning SDR receivers.  Great for contesters to quickly check all bands.  Greater coverage is possible at reduced performance.
  • Light-weight antenna structure fabricated from furniture-grade PVC yields a strong but very light antenna weighing only 2 pounds (not including power inserter or power adapter).  Great for both portable/camping as well as fixed installations.  Light weight and small size make for lower shipping cost – particularly compared to shipping from the UK.
  • Directly compatible with a low-cost speaker tripod stand (not included) for portable operation.
  • Compatible with light-duty rotator (recommended) for fixed operation.  Loop can be rotated to null interference by up to 30 dB or enhance desired signals.
  • Includes low-noise linear AC power adapter to generate clean 12 volts for the loop amplifier.  Unlike the DX Engineering antenna which requires 24 VAC, power can be easily supplied by 12 volt batteries during portable operation.  Reverse polarity and short circuit protection provided by automatically resettable fuse.

Eham reviews are very positive–so far, 5 stars on all six reviews.

I also discovered this short video of W9OY comparing the W6LVP loop to a full size 80 meter vertical (verticals are much more susceptible to noise than loops):

Click here to view on YouTube.

I am very curious if any SWLing Post readers have ever compared the W6LVP loop to the Wellbrook or Pixel Loop antennas.

I actually own the Pixel Loop and might very well purchase, review and compare the W6LVP loop later this year (if time allows).

If you own the W6LVP loop and/or have compared it with the Pixel or Wellbrook, please comment!

Click here to view W6LVP antennas on eBay.

Click here to view the W6LVP website.