Tag Archives: MW

Addendum: More Notes on the HF+ SDR on Medium Wave & Long Wave

In my recent post on the AirSpy HF+ vs Elad FDM-S2, I commented on medium wave reception only.

This past weekend I swapped out the Wellbrook ALA1530S+ for another Wellbrook loop, the ALA1530LN Pro. This LN Pro model is less likely to overload receivers at my suburban Tacoma, WA location. Both AirSpy and Elad radios performed admirably with the LN Pro and it was nearly impossible to find any reception differences on medium wave.

Before the antenna swap though I experimented with inline attenuation modules (“bullets”), typically used in cable TV installations. I used the same sample rates on the SDRs as described in the previous article. After some tests with different attenuation levels, I came to the following conclusions during daytime comparisons:

FDM-S2 with ALA1530S+ loop, medium wave: needs a minimum of 6 dB attenuation to avoid overloading. Anything less causes saturation of the spectrum & waterfall, “crunching” overload noises, and minimal or no received signal.

HF+ with ALA1530S+ loop, medium wave: I had to search diligently to find any signs of false signals or overloading, but finally noticed a weak image or spur of a S-9+60 dB (-13.5 dBm) local station on 1560 that was appearing very weakly on 1270 kHz, mixing with the station on that frequency. Sometimes it was there, other times the spur or image would drop down and disappear, leaving the 1270 signal alone. If I added just 3 dB of attenuation in the antenna’s feed line, the interference from the 1560 station was gone for good. The S-9+60 dB station is a very strong signal; it’s impressive that the AirSpy HF+ deals with this and similar powerhouse signals so well.

Long wave: Below are two screen captures from my local long wave reception in the evening, made moments apart with each receiver.

FDM-S2

HF+

As you can tell, there are a half dozen or so additional signals seen on the HF+ below 200 kHz that do not appear on the FDM-S2. These extra spikes are images or spurs from medium wave signals that were missing from the FDM-S2’s reception–bravo Elad! However, the remaining spikes on both radios below 200 kHz seemed to be noise or interference.

Each receiver had roughly equal performance in the bulk of the long wave spectrum, when I did A-B comparisons on the same beacon signals. I’m not a LW or NDB DXer however, so I can’t claim any expertise on these frequencies. In short, though, both radios seem neck-and-neck from about 200 to 500 kHz.

The DXer of LW frequencies may want to look elsewhere for a better performing radio than either the FDM-S2 or HF+. SWLing Post reader Tudor Vedeanu has commented that the SDRPlay RSP1A  and the Eton E1 work very well at long wave.

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

Spread the radio love

Valentino experiments with a ferrite sheet loop antenna

Valentino’s homebrew ferrite sheet antenna.

Many thanks to SWLing Post conttributor, Valentino Barbi (I4BBO) who writes detailing a novel approach to FSL antenna design.

Please note that I translated Valentino’s message from Italian to English via Google translate so please forgive any errors. Valentino writes:

FSL antenna radio enthusiasts typically use numerous ferrite bars with high cost, weight and scarcity,

Ukrainian ferrite bar producers have now finished stocks and have raised their prices.

Normally you use this site to build FSL antennas:
http://www.am-dx.com/antennas/FSL%20Antenna%20Design%20Optimization.htm.

I’ve been experimenting with a new antenna design for about 10 days comparing it with a classic FSL with 20 ferrite bars.

Listening to the audio signals are the same, only instrumentally the antenna FSL in ferrite film
Loses -2dB.

The construction is very simple in that the two ends overlap 5 mm.

I did this:

  • I took a sheet of A4 paper, I cut 5mm paper at one end.
  • I laid this sheet on a 10 cm (10 cm) diameter PVC tube.
  • The uncovered part of the tube is cut, now we will have exactly the exact diameter to fix the A4 sheet of ferrite with the overlap of 5 mm.

As for where to source a ferrite sheet, after much research I discovered this supplier almost by accident:

Click here to view the product page and ordering information.

In summary, the main advantages of this antenna design is weight, cost and availability of A4 sheet of ferrite.

Click here to follow Valentino’s antenna project on his website.

Fascinating, Valentino! Please feel free to share any further information about this FSL antenna as you experiment. It’s true that ferrite bars are becoming difficult to source. Sounds like this is an affordable alternative antenna design for ultralight DXing.

Spread the radio love

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.

Spread the radio love

North American and European medium wave signals into Oxford, UK

Hi there, I’ve been rather preoccupied of late, initially with the brilliant Tecsun PL-310ET and latterly with the even more brilliant Eton Satellit. However, in the background (as always), I’ve been trying to catch transatlantic medium wave DX. My listening schedule is broadly based on shortwave DXing during daylight hours – when I’m not at work of course, typically a Friday afternoon or at weekends – and always with a portable. Evenings usually start off with a tune around the tropical bands, followed by setting up the Elad FDM DUO to run some medium wave spectrum recordings overnight. In the past few days though, my daylight DXing has been bolstered by my NooElec RTL-SDR and ‘Ham it up’ upconverter. I bought the device over a year ago and after some initial exceitement, it quickly became quite obvious that I needed a reciever with a bit more ‘oomph’! However, it’s actually proving very useful to view signals on a  spectrum, even when I’m conducting most or all of my listening on a different (i.e. higher performing) receiver. Ultimately, the RTL-SDR is always going to be a compromise, with relatively limited sensitivity, but because by it’s very nature it has excellent selectivity, overall it’s a reasonable performer. My particular RTL-SDR performs quite well if a decent antenna is employed with it, such as a longwire or the Wellbrook ALA1530 active loop.

Anyway, back to the medium wave DX. In the past month or two, I’ve copied a number of stations from North America, with really nice signals, including WRCR Rampano – New York, WFED Federal News Radio – Washington DC, WENE – Endicott and WUNR – Brookline from Newton, Mass. I’ve also recorded a lovely interval signal from RAI Radio 1, Milano and further European signals from Magyar Radio, Budapest and Radio Slovenija 1, from Ljubljana. During the past 18 months or so of DXing, I have been mostly ignoring signals coming into Oxford from the continent. However, that changed a little after I stumbled across the RAI Radio 1 interval signal, which complete with the rather rousing Italian National Anthem, inspired me to dig out some more European DX. I’m actually finding European DX quite rewarding, particularly because it feels new again – not surprising since I haven’t listened to Europeans on medium wave for any length of time since the 1980s. I hope you enjoy the reception videos – embedded video and text links follow below and I wish you all the very best DX. 


Click here to watch on YouTube

 

Click here to watch on YouTube

 

Click here to watch on YouTube

 

Click here to watch on YouTube

 

Click here to watch on YouTube

 

Click here to watch on YouTube

 

Click here to watch on youtube

 

Click here to watch on YouTube

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

Spread the radio love

Video: Juan touts Panasonic RF-2200 performance & filter shapes

Many thanks to SWLing Post contributor, Juan Pablo Carlino, who writes:

Hi. I own one RF-2200 after buying it in eBay in March 2008. Since then it became my favourite portable radio and as everybody [has commented], its a pleasure to hear MW with it.

I explain this due to the fact that it has a good rotative ferrite antenna and also because the narrow and wide filters have a suitable shape for MW: at least in my country each MW is spaced from the other by 10 KHz, so you don’t need a very sharp filter. The narrow one is not so narrow, just enough to attenuate maybe 6 db the splatter from the louder station and not loosing audio quality.

When you tune around you have the impression that the filter shape suites perfectly for MW, making the audio quality very pleasant. I would never sell it. If you are interested i’ve captured a short clip while playing with it outdoor on 7 MHz band, hearing ham stations on AM, SSB and CW.

Pay attention to how loud and clear i was hearing stations at 400 Km in AM:

Click here to view on YouTube.

Many thanks for sharing your thoughts, Juan!

I agree with you completely. At least here in countries where MW stations are spaced at 10 kHz, I find the RF-2200 a mediumwave DX boss!

I’m constantly amazed with the RF-2200’s MW sensitivity and selectivity–and low noise floor. That combo, along with the filter shapes Juan mentions and the excellent built-in full-fidelity speaker make for a proper listening experience.

As I’ve said before, the RF-2200 is a radio with fortitude and purpose.

The only place I’ve ever really searched for an RF-2200 is eBay. I like eBay, because if you receive a faulty unit, you can typically return it or have some sort of recourse (as long as the seller accepts returns).

I would only buy an RF-2200 (or any vintage solid-state rigs) from a seller that has near 100% ratings with a number of radio sales in their past.  That is, if you’re seeking a working unit.

Though the RF-2200 is vintage and thus might eventually need repair. It’s ultimately reparable by a skilled technician, though.  My buddy Vlado, for example, has repaired 2200s in the past–indeed, we cracked my RF-2200 open a few months ago to clean contacts.

Panasonic RF-2200s typically cost between $175-300 for one that’s mechanically and cosmetically sound. Of course, NOS units go for much more and units with faults sell for much less.

I expect my RF-2200 will outlast me!

Click here to search for RF-2200s on eBay.

Spread the radio love