Tag Archives: Mediumwave

The Professor reviews the RFA200 external ferrite antenna

Many thanks to SWLing Post contributor, The Professor, who shares the following review of the RFA200 external ferrite antenna:


The Tecsun R-9012 and RFA200 MW antenna (Photo credit: The Professor)

A Quick Review of the RFA200

The Professor

I’ve considered saying something here about RFA200, as I bought one of these not long after its existence was announced on this blog a few months ago, but I’ve been hesitating because I didn’t have much good to say about it. A couple of times I’ve placed it up snug up against the the top of the two Tecsun sets I have handy (the PL-310ET and the PL-880) and found that despite a lot of knob turning it had little or no effect on improving signal on medium wave stations. I was not impressed.

But I guess I’ve kind of changed my mind on that. And oh yeah, I bought another radio. It’s funny how you can talk yourself into things when you’re talking someone else into something. But after I had mentioned to a reader here the other day that the very inexpensive Tecsun R-9012 was a worthy analog DX portable, I decided to drop twenty and pick one up for myself. After all, it was about the same price as a fancy Brooklyn hamburger. It arrived a couple days ago.

So, I have been playing with it a bit over the last few days. It’s as good as the other ones I’ve had which are the same basic radio (I’d mentioned that the bandswitch slider broke in a couple of mine). It’s single conversion. The bandwidth is a little wide, but it’s a very sensitive and simple analog set.

Yesterday I was going through the AM band and remembered that ferrite from Greece, and I pulled it out recalling that in my experience some radios are more susceptible to reception improvements using passive loops than others. Maybe this ferrite bar might be similar. And sure enough, the antenna made a notable difference this time. By placing it up against the R-9012 and tuning the thing I could certainly increase signal a bit. And I could even see it in the slight brightening or steadiness of the tuning light.

So, not a total waste money after all. I would emphasize that the difference in reception doesn’t seem to be as dramatic or sustaining as you might hear with a tunable loop antenna next to your radio. But it’s not junk either. Then again, for fifty dollars shipped it is a little pricey. Twice as much as a Tecsun tunable loop antenna, and two and half times more expensive than the R-9012 itself.

I found the best way to use this antenna is to tune the radio separately first and when you find a weaker signal you want to improve physically go ahead and rotate the radio until the signal is strongest and THEN put the antenna along the top of the radio and adjust the tuning knob on the antenna. Focus in on strengthening the signal you actually hear, going back and forth until it gets strongest. If you seem to be pulling up other stations it’s because the antenna adjustment will bring in adjacent stronger stations if you move it too far either way.

I’m surely not able to pin down the science involved in exactly how these things work, but perhaps somebody can chime in on this. I’m wondering if analog radio tuning in particular is better suited to the use of these tunable passive antennas, as opposed to PLL and DSP radios?

If you buy one of these be prepared to wait. At least mine took weeks to get here from Greece. And don’t expect miracles. But it seems rather well constructed, and will probably work with some radios. The seller has a 100% rating on eBay and has all sorts of interesting antennas for sale. I’m glad to see people succeeding in that business.


Many thanks, Prof, for sharing your fine review of the RFA200! Thanks for also mentioning the Tecsun R9012–I purchased one a couple years ago with the intention of reviewing it, then gave it to teenager who expressed interest in shortwave. I don’t think I actually put it on the air myself. I do enjoy simple old school analog radio–especially when making band scans. 

Click here to view the RFA200 antenna on eBay.

The Lazy Susan: Mario’s mediumwave companion

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who writes:

Grundig AN-200 Loop Antenna and Lzy SusanHere is a handy tip for those using small magnetic loops, like the Grundig AN-200. Using a simple Lazy Susan makes rotating the loop a lot easier as in the picture attached. It gives you a very smooth 360 degree rotation using a simple flip of a finger. Lazy Susans come in all sizes and luckily I had one already which fits the AN-200 perfectly.

This is a handy tip, indeed! In fact, I once spoke with a mediumwave DXer who told me that when he prepares for a DXpedition, he packs the Lazy Susan before he packs his portable’s batteries!

Lazy Susans are quite easy to find. Most “big box” retailers have them, Amazon.com has a massive inventory (affiliate link), IKEA and I’ve had incredible luck finding them at thrift stores for next to nothing! In fact, if you have a local thrift store with a large selection of kitchen accessories, you’ll likely find a Lazy Susan or two on the shelves.

Thank you for the tip, Mario!

FCC authorizes wireless power transmission experimental station

Many thanks to an SWLing Post contributor @experimradio who shares the following information from the FCC website:

Experiment authorized by FCC: WJ2XGB, 1800 kHz

https://apps.fcc.gov/els/GetAtt.html?id=202374&x=. [PDF]

Our Texzon Wireless Power™ system allows the Earth itself to be used for clean, safe and efficient transfer of power between any two points on the globe, wirelessly. The system represents a paradigm shift in the science of electromagnetics.

http://www.texzontechnologies.com/

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.

BBC Local: Mediumwave Closures in 2018

(Source: BBC)

We are closing a number of BBC Local Radio’s medium wave transmitters in January 2018. This will not affect listeners who use FM, digital radio, digital TV, or the internet to listen.

Why is the BBC switching off these transmitters?

We know how much our listeners value BBC local radio – and have invested significantly in this area through our commitment to funding Local DAB expansion and adding all English Local Radio services to Freeview. The savings from these closures will allow the BBC to continue to modernise its infrastructure in order to meet our listeners’ changing needs.

Why have these particular transmitters been chosen?

We assessed the coverage of each BBC Local Radio station on FM, MW and digital radio which highlighted stations where medium wave transmitters duplicated good FM or digital radio coverage. Following this process, we trialled the switch off of a number of medium wave transmitters and asked for audience feedback.

Taken together, the audience feedback and the coverage data have informed which medium wave transmitters are unlikely to be value for money in the longer term.

More information on why we are doing this can be found on the BBC blog.

Listeners can also use the interactive transmitter tool to see how they can receive their local radio service on other radio and television platforms or use iPlayer Radio to access their local radio service.