Category Archives: Field Radio

Don Pushes Portable Antennas Further: Loop Size, Performance, and Real-World Limits (Part 2)

Many thanks to SWLing Post contributor Don Moore–noted author, traveler, and DXer–who shares the following post:


Two Portable Antennas for Remote DXing (Part Two)

By Don Moore

Don’s traveling DX stories can be found in his book Tales of a Vagabond DXer [SWLing Post affiliate link]. If you’ve already read his book and enjoyed it, do Don a favor and leave a review on Amazon.

In my initial comparison of the PA0RDT mini-whip and the MLA-30+ MegaLoop, the mini-whip performed best on medium wave and the lower shortwave bands, while the loop worked better on the higher bands. But, I wondered, why should the MLA-30+ be restricted to that small steel loop? The wire loops I use with my Wellbrook ALA-100LN typically range from twenty to fifty meters in circumference.

I threw a twenty-five-meter wire over a tree branch and formed it into a delta with the MLA-30+ in the bottom center. Remember, I was testing in the northern Chicago suburbs. My SDRs were completely overloaded. Medium wave was useless and I had strong MW stations all over the shortwave bands. The MLA-30+ doesn’t have the same strong-signal handling capabilities as the Wellbrook. And there are a lot of strong medium wave signals in the Chicago suburbs.

So I took that wire down and replaced it with a loop of twelve meters circumference.

That did the trick. I had lots of signals on medium wave without the overloading. Here’s what the upper end of the MW band now looked like with the MLA-30+.

For comparison, here’s the same wire loop using the Wellbrook ALA-100LN. The Wellbrook has a slightly lower noise floor but otherwise the signals are about the same.

Out of curiosity, I replaced the Wellbrook power unit with the Bias-T from the MLA-30+ but left the Wellbrook antenna head unit in place. With this hybrid setup there’s no visible difference with the full Wellbrook.

I was satisfied with my findings but I still wondered how much wire the MLA-30+ could handle. A few weeks later I ran some more tests in Kansas, where I knew the dial wouldn’t be as crowded. The MLA-30+ easily handled a 25-meter delta loop without overloading.

Two weeks after doing the Kansas tests I was at a DXpedition in rural western Pennsylvania. The MLA-30+ worked fine with a 40-meter circumference loop, other than being a tad noisier than the Wellbrook with the same wire. So how much wire you can use with the MLA-30+ components depends on how strong your local medium wave stations are.

Findings

From the SDR images above it would be easy to conclude that with the right length of wire an MLA-30+ is just as good as a Wellbrook ALA-100LN even though it is significantly cheaper. But that’s not the full picture. Back in the 1990s my Drake R-8 cost about three times what my Sony ICF-2010 did.  All other things being equal, I would say that 95% of the DX heard on the Drake could have been heard equally well on the Sony. I wanted the Drake for the other five percent.

I have no doubt that if I did a very careful head-to-head comparison of the two units under serious DX conditions on the same wire that the Wellbrook would get things the MLA-30+ couldn’t. But I suspect the difference would be around that five percent mark. I’m willing to accept that tradeoff for an effective cheap light-weight travel antenna. And the MLA-30+ is like having two antennas in one. I can use it with the steel loop in limited space situations or with a larger wire loop when I have access to some garden space with a tree. Together, the MLA-30+ and the PA0RDT make the perfect DX travel antennas.

The only thing I didn’t like about the MLA-30+ was that pre-attached coax cable. It’s not the best quality and I’d rather carry my own cable. I’m not very handy with a soldering iron in tight spaces but at our recent DXpedition my friend Bill Nollman replaced the coax with a BNC jack for me.

The MLA-30+ now looks like this when connected to a wire loop.

Finally, I should address powering the MLA-30+ via USB. While it can be connected to a spare USB port on your laptop, I found doing that sometimes introduced a tad more noise. Instead I’ve been using one of those battery packs used for recharging cellphones. Mine is rated at 6700 mAh and it can power the MLA-30+ for over 48 hours before needing a recharge. But be sure to test yours before doing any serious DXing. I’ve read that some power packs have a minimum required power draw and will automatically shut off if the draw is too low.

Another Option?

While I was finishing this article I heard about another option from my friend Guy Atkins.  This antenna is a combination of the YouLoop with a low-priced Chinese made clone of the LZ1AQ amplifier. Some users say it’s better than the MLA-30+. Guy says it works well on shortwave up to 16 meters but he hasn’t tried it on medium wave. Guy says it’s a “low price, good value” antenna. I’m traveling in Southeast Asia for the winter but will definitely have to try this antenna when I get back to the USA. So maybe there will be a follow-up article next summer.

Links

[Note: Amazon links are affiliate and support the SWLing Post at no cost to you.]

Info on ordering a quality PA0RDT from Roelof Bakker. (Other cheaper versions have had issues with quality control.)

https://dl1dbc.net/SAQ/miniwhip.html

There are various versions of the MLA-30+ and the original MLA-30. This is the version that Mark Taylor recommended and that I bought.

https://amzn.to/3MEKjPY

There are numerous YouTube videos on using and modifying both versions of the MLA-30+. This one shows how to replace the coax with a BNC jack.

https://www.youtube.com/watch?v=OAqh2Lawwdc

Here’s the Amazon link for the YouLoop/LZ1AQ antenna that Guy has.

https://amzn.to/4s1RB09

And the same antenna on Ali Express.

https://www.aliexpress.us/item/3256808527623276.html

Retekess V112: An Ideal Ballpark Companion

The Retekess V112 takes in the scenery at a Lehigh Valley IronPigs game in Allentown, PA

by Aaron Kuhn

In my previous post for SWLing Post, I suggested the characteristics of an ideal ballpark radio and considerations for radio selection. While researching that post, I came across the Retekess V112 which ticked a lot of the boxes I recommended – compact, cheap, unobtrusive.

The Retekess V112 has indeed turned out to be a compact, affordable, and unobtrusive companion for enhancing the game-day experience at the ballpark. Priced at a consistent $15.49 on Amazon [SWLing Post affiliate link] for over a year now, this little red (or Gold) radio has exceeded my expectations.

Unboxing and Accessories (and what to replace):

While the physical packaging is a distant memory to me, the V112 comes with earbuds, a neck lanyard, and a Micro-USB charging cord.

  • Earbuds: While included, the provided earbuds are notably uncomfortable and were quickly relegated to the recycling bin. My ears are not your ears of course, and they might be salvageable with interchangeable eartips if you have some lying around, but it’s highly recommended to bring your own comfortable earbuds or headphones. This is especially important as the headphone wires double as the antenna, and reception can vary significantly between different pairs of headphones based on the cable. My older Apple EarPods offered good comfort and reception, while Sony MDRE9LP’s performed poorly. Experimentation of pairing the radio with low-cost IEMs would be an interesting project.
  • Neck Lanyard: Surprisingly, the neck lanyard is the hidden gem of this package. It allows the radio to hang around your neck, keeping your hands free for hot dogs and foul balls.
  • Micro-USB Charging Cord: While USB-C would be a welcome modern update, the included Micro-USB cable is understandable given the radio’s price point and older engineering. It’s hard to complain about the cable-port standard chosen when they give you the cable you need, and you probably have multiple other Micro-USB cables kicking around in storage boxes and drawers already.

Portability and Power:

  • Size and Weight: The Retekess V112 truly shines in its portability. Weighing 45 grams (0.1 lbs) and measuring 3.3 x 1.8 x 0.5 inches, it’s so small and lightweight that it’s easy to forget you’re carrying it, and easy to lose it in your pocket (like I have done multiple times!) This weight is even more impressive given the battery is built-in. I like to leave my earbuds plugged into it and wrap them around the radio body for transport, producing a tidy, tiny package of everything I need.
  • Battery: Battery life is another strong suit – I have yet to accidentally run it down, even forgetting to charge between games. I typically throw the radio on a battery bank on the way to the game, or shortly before the game, and have never run down the 500mah battery. I can’t find a stated battery life, and due to my experience really can’t estimate a runtime besides “long enough for extra innings.”

Features and Functionality:

  • Antenna: While relying on the headphone cable for an antenna does impact reception, it eliminates the bulk and vulnerability of a traditional antenna whip. This helps to make the radio instantly pocketable and prevents accidental seat-neighbor-pokes or damage. There’s nothing fancy such as selectable bandwidths to really help you out here, so you’re either going to have usable reception or you won’t.
  • Power/Mute Button: The power button cleverly doubles as a soft-mute, perfect for cutting out commercials between innings. A quick button tap when the last batter is out mid-inning mutes until you see the next batter up, and returns the previously set volume quickly.
  • Keypad Lock: The keypad lock function is invaluable for setting the desired volume and then tossing the radio in your pocket or letting it hang from the lanyard without accidental button pressings changing stations or volume.
  • Presets / Direct Frequency Entry: The lack of a number keypad for direct frequency entry is a minor inconvenience and my only real complaint, but in reality it’s lack of preparation. The radio does offer presets, making it easy to save your preferred stations before heading to the game – as long you remember to do so.

Future Wishlist:

If any radio manufacturers are out there listening (get in touch, Retekess or Tecsun!) I still think there’s a few features that would make an even better ballpark radio as discussed in my article from last year:

  • Bluetooth Headphone Support: There are a number of small radios on Amazon that advertise themselves as having “Bluetooth”, but when you dig deeper the feature just turns the radio body into an external speaker to your phone/tablet/laptop. The exception to the rule is the Prunus J-618 which claims actual bluetooth headphone support. Bonus points to manufacturers – allow two sets of paired headphones to be driven simultaneously. Finding comfortable Bluetooth earbuds is way easier these days at retail than finding a pair of wired earbuds, and you probably already own a pair to your liking.
  • Replaceable Parts: Implementing Bluetooth headphone support is going to require the move to an external antenna, and with that I’d love to see an antenna that can be easily replaced if it snaps off / is broken. I’m pro-repairability on electronics, so it would be great to see parts kits available at a small cost up-front with the radio to increase the likelihood the device lasts for years. Think antennas, plastic trim/doors, clips, lanyards, etc.
  • Selectable Bandwidth: I’d pay a little more for a radio that has a selectable bandwidth feature on both FM and AM. Legible commentary for a ballgame doesn’t require a very wide bandwidth, and this would go a long way towards turning an unstable/fringe signal into something more enjoyable. I’ve made use of bandwidth selection on Tecsun radios at the ballpark in the past and this is a sorely missed feature.
  • USB-C Charging: It’s 2025 – the world has moved to USB-C. Any device worth its salt these days should include a USB-C charging port, with actual proper USB-C PD support – none of that hacked up USB-A to USB-C junk.
  • Multiple Mounting Options: The lanyard on the Retekess V112 is great, what would be even more fun is some kind of clip that could attach to a stadium cupholder, or be attached to a seat in some fashion. Being able to strap a radio somewhere with bluetooth headphone support would be the ultimate convenience.

Conclusion:

For under $17 delivered to your door, the Retekess V112 is a great investment for live baseball enthusiasts. This radio has consistently enhanced my enjoyment of baseball games with its portable size, performance, and ease-of-use.

At $25, the Prunus J-618 looks like it might be a contender to the Retekess V112 throne and is one I’ll likely be checking out in the future. The Tecsun PL-368 is an attractive proposition for a ballpark radio, but in my mind provides more radio than you need, at a price-point ($75-$100) where I’d be afraid of breaking it or misplacing it in a ballpark environment.

For what it is, I’m not sure there’s much else that can compete at this price with the Retekess V112 for a low-cost, turn-key solution to live baseball play-by-play.

Initial Impressions of the Tecsun S-2200X

By Jock Elliott, KB2GOM

Bob Colegrove inspired this, with his excellent post “Pressing Buttons. Twirling Knobs and Throwing Switches.” If you haven’t read it, go do so now.

And it was our Maximum Leader, Thomas, who some time ago was asked “What’s the best shortwave radio?” His response (if I recall correctly): “The one you enjoy using.” That’s worth taking to heart. It doesn’t matter if you have the highest, techiest, super zoot receiver or SDR with the best lab numbers, if you don’t enjoy using it, how much will you really use it?

Given my age and my radio experience, my belief is that a real radio has a knob or button or switch for just about every function and a real tuning knob that doesn’t snap, crackle or pop as it changes between tuning increments.

The photos show the Tecsun S-2200X is studded with knobs and buttons, enough to satisfy an old retrocrank, but how would it perform? Dan Robinson had already reviewed it here. I respect his reviews, but I had to see for myself. With some trepidation I ordered the Tecsun S-2200X.

It arrived a couple of days ago. First impression: it’s a large radio – measuring approx. 15 inches wide, 7 inches tall, and 5 inches deep. It can run off 4 D batteries or 2 18650 rechargeable batteries, so technically it is a portable, but you’ll probably want something like a gym bag or backpack to transport it.

The fit and finish are pleasing, what you would expect from a radio in this price range. The front panel is studded with (if I am counting correctly) 33 buttons for activating various functions, 7 knurled metal knobs, a lighted analog signal strength meter, and a 3.5 inch by 1.5 inch (approx..) lighted liquid crystal display that serves as information central for the S-2200X.

On the right side are two BNC antenna connectors (one for FM and airband, the other for shortwave), a pair of clips for attaching a shortwave wire antenna, and a switch for selecting between internal and external antennas.

On the back are two hatches for installing batteries and inside one of the hatches, a switch for choosing between powering the receiver with D cells or the 18650 batteries. Also on the back, stereo line-out sockets.

On top, there are a retractable carry handle, a rotatable LW/MW antenna with a connector on the backside for an external LW/MW antenna, and a pull-up telescoping whip antenna for SW, FM, and air band.

On the left side is a port for plugging in the charging cable for the 18650 batteries.

Ease of Use

The S-2200X is straightforward to operate for basic operations (Memory operations will require consulting the well-written manual). On either side of the tuning knob are buttons for selecting FM, MW/LW, SW and Air bands, as well as selecting memory pages. Prolonged pressing of certain band buttons will activate Auto Tuning Storage of frequencies in that band, and these buttons are clearly labeled.

For shortwave, there are two buttons: SW+ and SW-, and, if you are in AM mode, these are used for incrementing between shortwave bands. However, if you are in either upper or lower sideband mode, these buttons will increment between amateur radio HF bands.

Below, and to the right of the tuning knob is a small button for switching between memory mode and frequency mode. A long press of this button will activate scanning of whatever band or memory page is active. To the lower left of the tuning knob is a button for changing tuning steps.

Below the signal strength meter is a 12-button keypad, and to the left of this are buttons for selecting synchronous detection, USB, LSB, and bandwidths. Volume and tone controls are knobs below the speaker grill.

As they used to say in the old sports car magazines: “The controls fall readily to hand.” If your goal is to pop in some batteries and start using the S-2200X right away, I found it easy to do. I particularly enjoyed the smooth tuning – both mechanical and audio – provided by the large, dimpled, tuning knob. On the unit I purchased, the tuning knob, though solidly mounted, wobbles a tiny bit.

Performance

The S-2200X acquits itself well. FM is top notch and the stereo audio is pleasing through headphones, which I routinely use to listen.

The MW performance was also satisfying, and I enjoyed using the rotatable LW/MW antenna to peak signals . . . it works! I tried plugging a Terk AM Advantage loop antenna into the jack on the backside of the rotatable antenna and found no discernable improvement in signal. To be fair, if you want the ultimate in MW DX performance, there are “hotter” MW receivers available, but I was not disappointed. I did not test LW performance.

Airband performance was average. An ATS scan of airband found five active frequencies in my area, and there is the ability to scan stored memories, stopping at each one for about five seconds.

On SW, the S-2200X delivers satisfying performance through its telescoping whip antenna. Using time stations as standards for testing, and switching between the whip and a 45-foot indoor wire loop antenna, the signal strength meter showed signals received on the whip often equaled or were only slightly less strong than those from the loop. Note well: if you conduct this experiment for yourself, there is a noticeable – perhaps one second – delay in the signal strength meter reacting to the change in antennas. If you are a SW  program listener, there are a variety of bandwidths and tone controls to fine tune the signal to your liking. I tried using the synchronous detection, and it sharpened the audio but introduced a pulsing quality to the signal that I did not like.

Most of my HF listening concentrates on single-sideband voice signals: the HF ham bands, Coast Guard weather forecasts, aeronautical voice communications, and the like. Here the S-2200X also delivers satisfying performance with impressive sensitivity on the whip antenna, a variety of bandwidths to choose from, and a fine tuning knob for dialing in the signal.

Noise Control

Now here is where the S-2200X got really interesting.

Not long ago, I became aware of a technique used by some of the experienced old hands. They would tune up on an SSB signal, then reduce the RF gain to remove as much noise as possible while preserving an intelligible signal. It made listening much more enjoyable and less fatiguing.

I tried this on my Icom IC-706 MkIIG and found that it was indeed an effective technique, but I wanted a radio I could park bedside so I could listen SSB signals on headphones while the Better Half drifts off to sleep. The Icom requires a separate power supply and an external antenna, and that seemed impractical for a bedside radio. Further, none of my portables have RF gain control.

The S-2200X does have a gain control. Here’s what the manual has to say about it: “When listening to longwave, medium wave, or shortwave, use the RF Gain control knob to adjust the gain for signals of different strengths and obtain the best reception.” I tried it on a SSB signal and it reduced the noise a little, but not nearly as much as the Icom IC-706.

Then I idly tried the squelch knob below the RF gain knob, and – tah dah! – substantial noise reduction, rendering the signal much more pleasant in my ears. The manual says: “Using the squelch control knob may reduce or suppress background noise when listening to LW, MW, SW, and airband.” As they say in the informercials: it really, really works!

Yes, but is the S-2200X really better than the other Tecsun radios that have similar basic circuitry but don’t have RF gain or squelch controls? The short answer is a definitive YES. Doing A/B comparison with my Tecsun PL-880, I found the two radios sounded about the same on a noisy band. But when I activated the RF gain and squelch controls on the S-2200X, it demonstrated a substantial advantage in “listenability” over the PL-880 with no RF gain or squelch controls.

Bottom line: based on my usage so far, I can heartily recommend the Tecsun S-2200X, particularly if you are interested in using it as a communications receiver for monitoring ham and utilities SSB signals.

Check out the Tecsun S-2200x at Anon-Co.

Raddy RF919

RF919 Bonus Antenna

I received a message yesterday from Raddy Marketing that they are offering a bonus antenna for the RF919 radio which will be shipped with future orders.

Here is the note they sent:

“All previous RF919 orders from our website or Amazon are eligible to request the new antenna. Customers can contact our customer service at [email protected] and provide their order number to receive it.”

I do not have any details about the new antenna, but wanted to post the info so folks who have purchased the radio as indicated above can receive the offer from Raddy.

Robert K4PKM

High Noon: Belka MW shootout part 2, with a review of the AFA200C active MW ferrite antenna

High Noon: Belka MW shootout part 2, with a review of the AFA200C active MW ferrite antenna

by 13dka

When I reviewed the updated Belka (gen3, 2022) for its MW/LW performance in October last year, I just wanted to know if it’s any good with just the whip antenna and used the XHDATA D-808 as a reference radio because it’s a Jay Allen 2.5-star average performer on MW and my expectations were not high for MW reception on a short whip.  To my surprise that average bar turned out way too low for the Belka!

That was sure asking for a comparison with the most sensitive MW radio I have and gave me hope to use the Belka for ultra-portable MW DXing on the move.  The omnidirectional whip doesn’t allow me to null out unwanted co-channel interference though, therefore I wanted to find a reasonably sized loopstick antenna to pair with the Belka.  Continue reading

Short Video: Paul tunes in Rádio Nacional da Amazônia with his ATS25 in McGrath, Alaska

Many thanks to SWLing Post contributor, Paul Walker, who shares the following video of his open-air DX shack in McGrath, Alaska. Paul notes:

I got my iRig working and recorded audio of Rádio Nacional da Amazônia on 11780 kHz directly from the radio into my phone and it sounds really good with such a strong signal here in ALASKA. Take a listen….

Click here to view on YouTube.

Thanks for sharing this, Paul! That does sound amazing–like a local station!

You, sir, are a true DXer! Anyone who regularly braves frigid temps to chase far-flung DX is made of some incredibly tough stuff!

Thanks for sharing, Paul!

Loop-On-Ground Antenna Part 3: Tom’s low-noise, low-profile, portable antenna evolves

Loop on Ground Antenna Part 3

(using multiconductor wire)

by TomL

It dawned on me recently, perhaps due to sloppy thinking or unintended distractions, that I never wrote about my modified Loop on Ground (LoG) receive antenna that I use at parks and such.  For over a year now, I have been using 3-conductor rotor wire bought cheap at the local hardware store and have wired the conductors in series.  Grayhat (Andrew) was the inspiration when he decided to create a folded dipole along the side of his house.

The usual construction of a LoG antenna for shortwave is a single wire of about 60 feet in circumference in order to not go above one wavelength for 20 meter band usage.  If you recall, going above one wavelength will start creating weird lobes in the reception pattern.  See – Loop-On-Ground Antenna Part 2.

However, I did not like this 19 foot diameter wire on the ground in public parks just waiting to be tripped over.  Like, the time when a horse got loose from its owners and almost tripped over my 60 foot wire.  I don’t think I would have liked the resulting lawsuit!

So out of fearful necessity I took some leftover RCA 3-conductor rotor wire, about 29 feet of it, and wired a loop with the conductors in series.  This gives about 81 feet of total conductive length.  But since it is folded onto itself, there is an undetermined loss of resonant length.  Callum (M0MCX) of DXCommander fame has experimented and found folded dipoles need three times more length in the folded section to reach resonance, so my loop is probably around 69 feet (electrically).  See – Fold the end of a Dipole Back – What’s Happening?.

In the picture below, the black wire with Ring Terminal at the bottom goes all the way around to the other side, soldered to the green wire, which goes around and is soldered to the red wire, which goes around to the Ring Terminal at the top, plus tie-wraps to hold the wires together.

The next picture is how the Wellbrook Medium Aperture preamplifier is connected to the loop with BNC cable that goes to the 12V power injector.  I have had this Wellbrook unit for maybe 6+years with no signs of problems.  WARNING – do NOT use the Wellbrook preamplifier in the presence of high powered RF energy like your Amateur Radio antenna pumped with 1000 watts from a  linear amplifier; the Wellbrook premap might just overload and get damaged!  I did use this loop and preamplifier at last year’s 2022 ARRL Field Day and was able to get away with it because we were only using 100 watts per station.  Listening to the 9pm 3916-net trivia group was fun but I still needed to keep it away from the transmitting antennas. Continue reading