Category Archives: Software Defined Radio

Nooelec LaNA HF Barebones Ultra Low-Noise LF, MF & HF Amplifier

Many thanks to SWLing Post contributor, Chris Rogers, who writes:

[Here’s] an interesting new amplifier that is suitable for SDR’s and antennas like Youloop etc with Bias-Tee provision. Unsure of the specifications.

The ad claims made in North America:
https://www.nooelec.com/store/lana-hf-barebones.html

Thanks for the tip, Chris! Yes, it’s a bit of a surprise it’s made in North America. I must admit that these Nooelec amps all look the same to me, so I’m guessing this model is simply the latest iteration?

Post readers: have you used this particular LNA? Please comment!

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Tom builds a portable Loop-On-Ground antenna

Many thanks to SWLing Post contributor, TomL, who shares the following guest post:


My First Loop-On-Ground antenna

A number of people have mentioned the Loop On Ground (LOG) antenna in the past as a good receive-only antenna.  I did some research but could only find a few examples by amateur radio operators.

Matt Roberts (KK5JY) has a good article including some antenna theory and measurements, you can find it here:

http://www.kk5jy.net/LoG/ 

Someone named Tom (KG3V) has a write up on it but it is a little short on details:

https://kg3v.com/2020/01/04/loop-on-ground-the-simplest-receive-antenna-you-will-ever-build-and-it-works/

Stana Horzepa (WA1LOU) has something similar:

https://tapr.org/loop-on-ground-log-antenna/

I also read somewhere that for transmitting, a LOG antenna is useless as it radiates much of the energy right into the ground!  But I didn’t care about that.  I needed something for receive I can deploy easily without supports and take down just as easily.  As you may recall, my home condo is literally saturated with noise and I cannot null it out.  So a wire looped on the ground is supposed to work?  You bet it does!

Of course, there are some conditions to meet.  There has to be enough flat ground away from people or pets (or lawn mowers!) who would get tangled in the wire on the ground.  The wire should be as close to the ground as possible (although I had good results laying the wire on top of cut grass).  The loop of wire can vary in circumference from about 20 feet to 150 feet (the shorter length will stay in an omnidirectional pattern higher in frequency but lower in signal pickup and vice-versa for the longer length).  The wire needs to be insulated.  That’s about it!

So, off to the hardware store to buy a cheap spool of 100 foot 18 gauge speaker wire.  But, the articles mention using a balun and they all made their own.  I did not feel like doing that (I am not that good at making things from scratch) and I did not want to spend money ordering one. More reading somewhere informed me that my existing Wellbrook Medium Aperture loop amplifier has a built-in balun at the antenna side of the device.  Hallelujah!

I bundled together the wire, Wellbrook parts and battery supply, small laptop and Airspy HF+ to my favorite Lake Nelson Forest Preserve.  The shelter there is little used and is adjacent to the prairie with cut grass.  It did take a good 15 minutes to lay out the 100 feet of wire on the ground while trying to keep it as flat as possible. And I did not have enough space for a circle, so I ended up with an oblong shape.  The long sides are facing directly north-south, so in theory (I think) this gives me an oblong shaped reception pattern east-west.  The photo shows half of the wire laying on the grass.

I ended up with this setup on a picnic table at the rear end of the shelter.  The coax wire goes from the Wellbrook amp into its power module, then to a Cross Country Wireless preselector, then to the Apirspy HF+ and laptop.

I was really impressed by the signal strength of the usual suspects like Radio Nacional da Amazonia.  I could see that the Wellbrook amp was boosting signals across the board with only a little extra noise.

I use the preselector to try to keep the Airspy radio from overloading, especially mediumwave broadcast signals which can sound like a small amount of extra “hash” type noise in the background.  I have since added into the accessory chain an old Kiwa Electronics BCB filter that does a great job of knocking down the frequencies below 2 MHz.

I have also since added a water resistant box to enclose the Wellbrook amp to keep it safe from getting stepped on or too wet.

Also, a couple of weeks later I was able to go to a campgound and try out 60 feet of wire but the result was noisier since I was surrounded by RV vehicles in a crowded campsite.  It was not horrible and I was able to listen to some good radio stations but location can matter with any antenna.

I hope you like the recordings below.  Because of some serious health issues this summer, these May 31 2020 recordings & report are just being published now (I am recovering slowly but surely!).  My small laptop is under-powered, so I was only able to record MP3 files one at a time.  It kept me busy as I went from one frequency to the next and kept recording anything I heard.  I was able to hear a couple of stations I never heard before and that is a success in my book.

It remains to be seen if this antenna is as good as my 19 foot vertical antenna attached to the top of the car roof, especially low-angle DX signals.  Maybe you will have the chance to experiment as well and share your experience, too.  Now, will a small loop-on-ground antenna around my car parked late at night at a far corner of the grocery store work OK???  I will have to try it!

Recordings (crank up the volume if it is too weak):

22:00 UTC, Radio Saudi (Arabic) 11915 kHz

22:04 UTC, KDSA Adventist Radio (Indonesian) 11955 kHz

22:14 UTC, KDSA Adventist Radio (English) 12040 kHz

22:20 UTC, Voice of Korea (Japanese) 11865 kHz

22:23 UTC, Yemen Radio (heavily jammed) 11860 kHz

22:35 UTC, Radio Brazil Central (Portuguese) 11815 kHz

22:50 UTC, WWV booming in 10000 kHz

23:11 UTC, UnKnown (might be FEBC) 9795 kHz

23:15 UTC, China Radio Int’l (Spanish teaching Chinese, from Kashi) 9800 kHz

23:17 UTC, China Radio Int’l Business Radio (from Xianyang) 9820 kHz

23:19 UTC, China Radio Int’l (Chinese from Urumqi) 9865 kHz

23:21 UTC, Voice of Korea (Korean) 9875 kHz

23:23 UTC, Maybe Radio Taiwan without jamming from CNR 9900 kHz

23:34 UTC, China Radio Int’l (Chinese from Bamako Mali) 7295 kHz

23:43 UTC, Radio Nacional da Amazonia 6180 kHz (& 11780 kHz around 40 seconds)

23:50 UTC, MAYBE China PBS from Xinjiang in Kazakh (nothing else listed on schedules) 6015 kHz

23:56 UTC, Radio Mali (French announcer humming to music and acting crazy) 5995 kHz

00:07 UTC, Radio Rebelde (Spanish w/clear signal, Bauta, Cuba) 5025 kHz

00:15 UTC, 75 meter Amateur Radio 3913 kHz (LSB)

00:27 UTC, CHU Ottawa 3330 kHz

00:30 UTC, XEPPM Radio Educacion (Spanish Mexico City) 6185 kHz


This is brilliant Tom! Thank you for sharing. 

Our antenna guru contributor, Grayhat, has been encouraging me (understatement!) to build a Loop-On-Ground antenna but I haven’t done this yet because, at home, our driveway would interfere with its deployment. That and I have no RFI to speak of in my rural/remote home so my skyloop antenna is tough to beat. But having one available for portable use would make a lot of sense.  I’m going to put this on my 2021 project list!

Post Readers: Do you use a LoG antenna at home or in the field? Please comment!

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Spectrum recordings with the new Belka-DX and a Zoom H1 digital recorder

I’m so pleased to see a fascinating new post from our friend London Shortwave this morning.

In his latest article, London Shortwave demonstrates how he has been making super simple spectrum recordings by pairing the new Belka-DX receiver (which has an I/Q out port) with a Zoom H1 handheld digital recorder. The recorded I/Q files are then imported into SDR# for tuning and listening.

The process is quite easy to follow and he includes a number of examples–a highly-recommended read!

Click here to read his full article.

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Radio Deals: Airspy Black Friday Sale 2020!

If you’ve been thinking about pulling the trigger on an Airspy product, now’s the time!

Airspy is once again offering huge discounts during their 2020 Black Friday promotion.

For example, their Airspy HF+ Discovery SDR–which I consider to be one of the best HF SDRs on the market–is 30% off ($119 US). This is a phenomenal deal on an amazing SDR!

The YouLoop antenna is only $20.97 US. Click here to read my review of the YouLoop.

That’s such a good deal, I’m contemplating the purchase of a second one.

Both the HF+ Discovery SDR and YouLoop are the major components of my portable SDR DXing kit. During the Black Friday sale, you can purchase both for $141 US! That’s much less than the normal price of the HF+ Discovery alone.

It seems all Airspy distributors are participating in the sale, so click here to find the distributor that ships to your part of the world.

[Just found out the Frugal Radio channel also discovered this sale!]

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SDRuno V1.40.2 released

(Source: SDRplay via Mike Ladd)

SDRuno 1.40.2 has been released. This is to fix the ini file corruption issue we posted about recently, but it also introduces some new features and more plugin functionality. Release notes can be found here: https://www.sdrplay.com/docs/SDRplay_SDRuno_Release_Notes.pdf

Please note that the SDRplay plugins and community plugin installers that are included in the SDRuno installer are also available on our downloads page and will be updated when needed independently of SDRuno. If you are installing them separately, please make sure you get the right installer for the version of SDRuno you are using.

Added
• Hotkey to start/stop stream – P.
• Support for loading and saving profiles (supports multiple VRXs).
• Profile file area in the memory panel below the memory bank file area.
• Button in the memory panel to store profiles.
• Checkbox in the main panel settings to disable and hide the Bias-T function.

Changed
• LO and VFO for VRX#0 now separate on start-up and when loading a profile.
• ini file is only saved when SDRuno closes cleanly.
• Halved the size of the memory bank file are in the memory panel to accommodate the profile file area.
• Overhaul of the minimise and restore functionality (now only main panel appears in the taskbar when minimised).
• Plugin Control panel look/feel now matches the rest of the SDRuno panels.
• The default directory for community plugins is now the same as in the Community Plugins installer for ease of use.

Fixed
• Memory panel being flagged as modified when it is not.
• Check for new version can sometimes get something other than the version number.
• HDR 630m band was non-functional due to the wrong centre frequency being used.
• If decimation had been set before the 10m band was selected, the decimation value would be wrong after the band was unset.
• Cancelling wav file open window on start-up allowed SDRuno to continue to open with no input.
• SDRuno could crash on start-up if the memory bank referenced to be open was empty.
• Clicking on the frequency title in the memory panel to sort the frequency list could cause the
current band to be unframed.
• The Plugin Control panel will no longer allow the SDRuno Plugins folder to be selected when
using the right click method as community plugins should be stored elsewhere.
• Manual frequency entry after being band framed did not disable the notch filter.
• Pausing a memory scan could make it impossible to un-pause.

Known Issues
• SP2 CWAFC drift issue (Zoom/window size/freq display)
• IF output mode disabled SP1 spectrum mouse clicks

Plugin information can be found on: https://www.sdrplay.com/plugins/

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Paul discovers fake RSP1As being sold on AliExpress

“RSP1A” Clone

Many thanks to SWLing Post contributor, Paul Rawdon, who writes:

Hi Thomas

I was browsing through AliExpress and came across a cloned version of the SDRplay RSP1A, the price being asked is slightly lower than the genuine version from SDRplay. I notified SDRplay of what I found. They pointed out that as it is a clone it is unlikely to work with any of their software.

You may like to notify readers of this because it really amounts to a scam.

The AliExpress advert can be seen here:

I do own the genuine RSP1A and yes it lives up to the positive reviews out in internet land.

Thanks for the work you put in to SWLing.com there’s always something interesting to read.

73s

Paul Rawdon

Thank you for bringing this to our attention, Paul! Yes, this is a blatant fake RSP1A clone and, as you say, only a few dollars cheaper than the real thing. I suppose the manufacturer is simply hoping the buyer doesn’t realize it’s fake.

If you’re interested in purchasing an SDRplay product, go directly to their website and purchase from an authorized distributor. Not only will it carry a warranty, but you’ll know it will work with SDRplay’s SDRuno app.

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