Category Archives: Reviews

TomL’s Guide to Audio Plugins For Radios: Part 2 – SDR Recording

Many thanks to SWLing Post contributor, TomL, who shares the following guest post. Click here to check out all of the posts in this Audio Plugin series:

Audio Plugins For Radios, Part 2 – SDR Recording

by TomL

I started investigating using the old Kenwood transceiver to send audio to my laptop and process the receive audio using VST Host for a number of functions: Noise reduction, Equalization, reduce Sibilances and fading distortion, increase presence of vocals without sounding boxy, etc. It was a qualified success depending on what VST apps I used, in what order they were used, and what settings each of them were set to. In this episode of ongoing discovery, I will attempt to show how easy it is to OVER-process the shortwave broadcast audio plus comparisons to my regular Audacity post-recording treatment.

Audio Examples

I noticed for the first time that the SDR creates a somewhat compressed file which can be seen when comparing the Waveforms of SDR vs. VST Host output files. This means that the unprocessed SDR file will always appear to sound louder because of this compression. This loss of Dynamic Range makes it harder to do the comparison. Therefore, the Audacity-only examples below are reduced 3dB or 5dB to maintain apparent loudness.

Example 1: KBS Weekend Playlist – S6-S9 signal, somewhat severe fading and moderate polar flutter.

SDR Console 3.2 using my usual NR4 set to 2dB Reduction, 30% Smoothing, and 3dB Rescale plus a Blackman-Harris-7, 5.3 kHz filter.

AUDACITY file is using my usual Audacity noise reduction:

VST version 2: Used my first set of VST apps. Sounds harsh with hash-noise and overdriven:

VST version 3: Used way too much bass, too much grunge, attenuated highs, still overdriven:

VST version 4: Using a different order to the Denoiser apps, added in Modern Exciter app, cut back on some bass but still too much, and overly forward sounding midrange:

VST version 5: My current Baseline setup. Adjusted the Denoiser apps, less extreme bass & treble, adjusted the De-Esser app, set the midrange to be less forward with just a single setting:

To my ears, Audacity processing is nice but as discovered before, sounds compressed and does not reduce some of the other problems inherent in shortwave signal fading and loss of musicality. It sounds utilitarian. Also, the noise is a bit more gnarly.

Versions 2-5 go through iterations of listening to the exact same segment over and over (and over) and trying different VST apps and settings. I think my comments are mostly accurate next to each version. However, you may think differently and perhaps prefer the sound of one of the other versions?

Example 2: Encore Classical Music, WRMI (fading S9 signal) – Audacity vs. Version 5 VST settings. VST is quieter and sounds less harsh than the Audacity version. A generally more smooth sound.

Example 3: RCI in Russian, S7-S9 with moderate polar flutter – 7kHz filter in SDR Console but VST Host is using BritPre, an analog preamp using a 6 kHz low pass filter to try to reduce DSP filter “ringing”. It shows some interesting possibilities.

Example 4: RCI in Russian – Music from the same broadcast and VST Host setup in Example 3. The screeching flute is under more control and strings more defined in the VST version.

Conclusions

I like the results of the audio processing that eventually ended up with “version 5” (plus the possibilities at 7kHz, too). It is not Earth-shattering but is an incremental improvement in my opinion (there is always room for improvement). I can use it in a simple Workflow anytime I want to record something off of the SDR. Also, I had already been using Voicemeeter Pro, a software audio mixer. It is setup with different profiles to do SDR, Ham, FM Broadcast, and now, VST Host audio routing. This process took a long time but seems satisfactory to use as a Baseline setup, which then can be tweaked slightly depending on various types of audio coming from the SDR. These changes in VST Host can be stored as their own unique profiles for audio processing.

However, a word of warning! Messing with Windows audio Sound settings and mixer software is potentially a confusing process and one can easily end up with a spaghetti-pile of conflicting connections, no audio output, doubled echo output, distortion, way too loud, way too soft, etc. If you start this experimentation, make sure to write down your current Windows Sound settings, both the Playback and the Recording settings for each item listed.

Having an SDR radio + Voicemeeter + VST Host is a very flexible setup. I can now safely say that the only thing I need Audacity for is to Normalize the peak audio to the -1 dB broadcast standard volume, which is a HUGE time saver. The SDR Console IQ files can be scheduled and processed from there at a later time. Also, the use of Voicemeeter Pro allows me to switch when to use VST Host anytime I feel like it, and Voicemeeter Pro comes with its own (manually engaged) Recorder.

Part 3 of this series will discuss Technical details for my setup. Your setup may need different settings or you may find a better way than I did. This will take some dedicated time.

Happy Listening and 73’s,

TomL

Click here to follow all of the articles in TomL’s audio plugin series.

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Sometimes simple works . . . really well! Exploring the CCrane EP PRO

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By Jock Elliott, KB2GOM

This particular adventure began about three weeks ago with an email from CCrane. “Timeless, Easy to Use with Long Range Radio Reception” the headline read. Further, the accompanying text promised: Comes with needle and dial tuning, one button for power, one button for a bright display light, and has no clock or alarm. The radio in question was the C.Crane CCRadio-EP PRO.

The “Long Range Radio Reception” initially caught my eye, but the simplicity of an old-fashioned “needle and dial” – what I call “slide rule” – tuning” also appealed to me, so I emailed CCrane, asked them if they would like to send me one for review, which they did, without charge.

While waiting for the EP PRO to arrive, I examined the photos of the EP PRO on the CCrane website, and I noticed something peculiar: a switch on back for choosing between 9 kHz tuning steps and 10 kHz tuning steps. Whaaat?! Why in the world would you need such a thing on a radio with needle and dial tuning?

We’ll get to the answer to that question shortly, but first let’s take a tour of the CCrane EP PRO.

The case is a rectangle with rounded corners that measures 11.4″ W x 7.3″ H (8.4″ H with handle) x 2.75″ D and weighs 4.5 pounds without batteries. Starting on the left front panel, you’ll find a 5-inch speaker. To the right of that, there is the slide rule (needle and dial) tuning setup, with a small red light on the right side that illuminates when a station is found. Below that is a CCrane logo and further below is a switch for selecting AM (520 – 1710 kHz, 10 kHz steps; 522 – 1620 kHz, 9 kHz steps), FM (87.5 – 108 MHz), or FM stereo; a knob for adjusting bass, a knob for adjusting treble, and a knob for choosing between narrow (2.5 kHz) and wide (6 kHz) filter bandwidths.

On top of the EP PRO are a red POWER button, a black button for lighting the tuning dial, a flip-up carry handle, and a 36-inch telescoping antenna for FM reception. (Inside the case is a ferrite bar antenna – 12mm x 200mm (7.9″) long with CCrane’s Twin Coil Ferrite® technology.)

On the right side of the case at top is the tuning knob, below that a knob for fine-tuning the internal antenna for AM reception, and at the bottom a knob for volume. On the left side of the case, you’ll find a 1/8” stereo headphone jack, a line-in jack, and a socket for plugging in an external 6-volt AC adaptor which is provided with the EP PRO.

On the back of the radio is a hatch for installing four D-cell batteries (CCrane says it will run for about 175 hours at moderate volume with the dial light off), external antenna connections: spring loaded for AM and “F” connector for FM, a switch for selecting internal or external AM antenna, and the switch for selecting 9 or 10 kHz tuning steps.

That’s it. The EP PRO is almost Zen-like in its simplicity. There are no seek buttons, no automatic storage functions, no memories, no key pad. And there is a darn good reason for that. It turns out that the immediate predecessor of the EP PRO, the CCrane EP, was created by Bob Crane because his mother wanted a very simple radio that was easy to operate. The CCrane EP, a true needle and dial analog radio, was the result.

Bob believed that, besides his mother, there was a market for such a radio, and there was. Unfortunately, after a time, the analog chips necessary to build the CCrane EP became unavailable. As a result, the radio was redesigned internally using modern digital chips (essentially the same as those in CCrane’s model 2E and 3 radios) while keeping it simple and easy to operate. So inside what looks like an old-fashioned analog radio beats the heart of a high-performance digital radio that combines the high sensitivity needed to hear distant stations with excellent selectivity to block signals from the side.

In my view, the EP PRO is great fun to operate. In the predawn hours on a weekend morning with the rain falling softly outside, I started tuning slowly across the AM dial with the EP PRO in my lap. Near the bottom end, a couple of sports mavens were chatting about a pitcher who had a couple of rough two initial outings and then had “settled in.”

A bit further up the dial Dionne Warwick was telling me to “walk on by.” Then I ran into a music station competing with a talk show considering “the Bible, angels, and UFOs.”

Up the dial some more, apparently a good deal on a high performance car could be had at a dealership in Connecticut; then an air quality report for New York City, a female voice delivering a long discourse in French and so on up the dial.

I was impressed at the number of stations that the EP PRO was pulling in, and it brought me back to the simple joy of tuning around to see what’s on the air.

Each time a discernible station appeared, the red tuning LED would light up. As needed, I used the antenna tuning knob and the bandwidth selection switch to tweak the signal. The needle and dial tuning gives an approximate indication of where on the band the radio is tuned, so if you want a positive ID, you need to listen for a station ID or some other clue to the station’s location.

At one point I jumped to the FM dial and found I could easily pick up many FM stations even with the whip antenna collapsed. In all, I am of the opinion that both the AM and FM sides of the receiver are pretty “hot,” and at no time did I find myself wishing for an auxiliary antenna for more signal. Further, the sound through headphones or the speaker is very pleasant indeed. In my mind, the relatively unadorned exterior of the EP PRO belies its outstanding performance. To stretch an analogy, it’s a nitro-burning funny car in the body of a Honda Civic, and you don’t have to be a genius to drive it.

If you’re looking for a high-performance radio that is easy to use and sounds good through speaker or headphones, the CCRadio EP PRO delivers the goods. For a content DXer like me, the EP PRO encourages me to tune around and discover the magic of radio all over again.

CCRadio-EP Pro Retailers:

C.Crane
Amazon.com (SWLing Post affiliate link)

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Jack examines the C.Crane CC Skywave SSB 2

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Many thanks to SWLing Post contributor, Jack Kratoville, who shares the following guest review:

CC Skywave SSB 2: Thoughts and impressions

by Jack Kratoville

I had no intention of purchasing this radio. I already own two of the original Skywaves and, not big into Ham communications, saw little need for the upgrade. But as I was looking at the new SSB 2, my wife walked by and said, “Don’t you already have that one?” I told her it was the updated model and it’s on sale. “You should get it,” she replied. Sometimes it is best to listen to your wife.

My curiosity in the SSB 2 was the “slightly improved” audio and other updated features. It was shipped to my home for $149 complete and I eagerly opened the box. Putting it through the initial paces, I was highly disappointed. Some buttons didn’t work, and the “slightly improved” audio was harsher than the original. It was going back. In a final desperation, I stuck a paper clip in the reset hole and all functions came to life. While I still wasn’t impressed with the overall audio, I would spend more time with it. I’ll address the audio later, but let’s look at what this radio was intended for and how it stacks up to that challenge. This is a communication device, designed specifically for people looking for interesting and far away signals. As far as I can tell, it’s the only radio with “SSB” in its name – so let’s start there.

I have the Digitech AR1780 and the Eton Executive Satellit with SSB capability. I’ve explored both upper and lower sidebands on both. It always seems like too much work; pressing multiple buttons multiple times adding that the Digitech is a notoriously slow scanner. I enjoy them both, but SSB seems like an afterthought. The Skywave SSB 2 is far easier to track down and tune in signals. CCrane includes some tips in the booklet, and I find myself hunting for Ham conversations almost nightly. I haven’t had to attach an external antenna as of yet as I find something without them. If the primary purpose of this radio is to bring a capable SSB portable to your pocket on any adventure, CCrane has scored big. I’m still not a hard core listener, but this radio is very satisfying and I tend to check out the side bands much more frequently.

Next up is the SW band. The SSB2 has a longer antenna and I think it serves well pulling in more distant signals. First thing I noticed is that the SSB2 scans slower than the original Skywave. Perhaps this is due to the ability to detect single side band signals, but I’m not so sure. The original is quite speedy, the SSB 2 seems more normal. The best features are the external antenna options and the hardware provided in the box. Wherever you travel, you can easily hook up an antenna directly into the radio, simply using wire that attaches to the accessories in the box. There is a provided reel antenna, so your options are plentiful. I don’t get any overload, but I’m also not on top of any local signals. I have to say, as a communications device, this radio is designed to please.

Aircraft also benefits from a longer whip and external options. I can just get the feed from my local airport (about 5 miles away). The SSB2 gets the airport weather service clearly. There’s an updated scanner that is perfect for monitoring 2-3 signals at a time. This is a big improvement.

The weather band is one of my favorites and have always enjoyed it on the Pocket and Skywave. Here we have one step forward and one back. I understood why the original Skywave didn’t employ the tone switch on WX. There’s not a lot of dynamic audio here. But the SSB2 does which makes it a bit clearer and certainly louder. Very happy with that update, however when I push the presets on the SSB2, nothing! On the original, pushing 1 through 7 moved you to that WX channel. Now you have to slew through signals using the knob or buttons. Why would they omit this? At my home location, I receive 1, 4 & 7 and would simply press the preset I wanted to hear. Losing this capability makes no sense at all.

AM/MX. This band is always a CCrane strength and the SSB2 will not disappoint. Excellent sensitivity, filtering and scanning options makes this a top tier pocket portable.

FM. Better antenna, better reception. I think it’s a hair more sensitive and selective than the original Skywave, but listening to the FM band leads me into my biggest gripe, the audio.

“Slightly Improved” is a way of saying “don’t expect too much.” At first, I was highly disappointed. Even on “Voice,” the FM band sounded shrill and fatiguing. I almost returned it that first day. I decided that it was better to give time and put it through various paces and locations. Here’s my personal assessment. While audio dynamics is as personal as one’s favorite color, I must start by saying they did make a sizeable effort to improve this radio’s sound – to a degree. Excluding FM, the audio is louder and fuller. I would go as far to say it’s a bigger improvement than they give themselves credit for, especially with SW, SSB and WX. But with FM, they could have trimmed that high end 1-2db and it would have been so much better. U.S. FM signals are overprocessed to begin with and this radio highlights that flaw immensely. (The PL-310et does as well, but with slightly better low end to balance the sound). I’ve brought the radio outside, listened to the non-commercial locals and various low key programming – when the high frequencies are more muted, this model sounds much better than the original. OK, admittedly people are not laying out $160 for this radio to listen to the Zombies, U2 or even Doja Cat, but I don’t think it would have taken much to make this radio audibly more pleasant on all bands.

Where the audio does suffer is at low, low levels. This is not for listening in bed late at night. The improved amplifier has to send more energy to the speaker and that creates a low-level hiss – even when the volume is at zero. This is not a Skywave SSB2 issue, it is an issue with most audio devices trying to pump more into a smaller speaker. Most radios suffer from this to a degree (the original Skywave does not), but some are better than others. The SSB2 is very noticeable.

I honestly feel CCrane put in a big effort trying to please their core base with multiple adjustments to this radio. The screen light is better dispersed. When you shut the unit off, it gives you the time before the light extinguishes. Switching on and off or between bands, the audio fades up and down – better than unexpected loudness. The tuning knob is vastly improved with satisfying clicks and no jumping over frequencies. The volume knob is stiffer with less play. The buttons are better, and the adjusted layout is extremely intuitive. I’m not a huge fan of the current style, but it makes sense. CCrane designed this radio to be more in line with the CC Pocket, giving their portable lineup familiarity between models. I’d prefer the page and memory numbers to remain on screen, but it’s extraneous information. I don’t listen through the earbuds, but they are working on whatever clicking problems occur when switching between bands.

No radio will ever be perfect nor please everyone, but I remain a fan of CCrane. For Ham and SW enthusiasts on the go, this radio is worth your consideration. You can buy cheaper, but you will only get what you pay for. My original Skywave, purchased in 2015, continues working like it did brand new and remains my #1 travel companion. Well, number two behind my wife.

Click here to check out the Skywave line at C.Crane.

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A Review of Two Medium Wave Signal Boosters

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By Jock Elliott, KB2GOM

It was the survey that Thomas, our Maximum Leader, conducted that got me to thinking about this.

The survey revealed that portable radios were used 38.6% of the time by SWLing Post readers as their “daily driver.” I like portable radios, too, and use them frequently. Hold that thought for a moment.

I also like medium wave DXing (content DXing, really, I enjoy tuning around for unusual programs) because, as Gary DeBock once put it: “It’s a target-rich environment.” With that in mind, I was exploring the CCrane website and found a couple of items – the Terk AM Advantage and the Twin Coil Ferrite® AM Antenna Signal Booster that looked like they might help portable radio listeners who want to pull in medium-wave signals better. I asked the CCrane folks if they would like to review both products, and they sent them to me without charge.

Bottom line: they both work for boosting reception of medium-wave signals.

The Terk AM Advantage is a nine-inch tunable loop encased in plastic, and it requires no power supply. Simply place it near your portable receiver and just the dial to the desired frequency, and you could get up to a 20 dB gain in the signal you want to hear. The loop of the Terk AM Advantage inductively couples with the ferrite antenna inside your portable radio, although the unit comes with a direct wire connector that can be used with some radios.

I tried the Terk AM Advantage with my CCrane Skywave SSB on an AM that was coming in with a lot of static at my location. Without the AM Advantage, I had 3 bars of signal strength. As soon as I placed the AM Advantage close to the Skywave and adjusted the tuning knob, the signal strength increase to 5 bars, and the audio was much easier to hear with less noise.

With my Tecsun PL-880, which has a numerical signal strength meter, signal strength was 11 without the AM Advantage, but with the AM Advantage, signal strength increased to 14, and it was much easier to hear. The Terk AM Advantage definitely provides a modest boost in signal strength and clarity, is easy to use, and requires no batteries or external power supply.

The Twin Coil Ferrite® AM Antenna Signal Booster is more complicated. It consists of an antenna element that measures 8.5″ W x 2.5″ H x 1.25″D, a tuner unit that measures 3.25″ W x 4.25″ H x 1.25″ D, a small ferrite stick, and some patch cords. It comes with an AC adaptor and can also be powered by a 9-volt battery. For radios with external antenna connectors, package also includes a RCA female patch cord to two bare wire ends.

Set up is pretty easy: connect the tuner unit to the antenna element with a patch cord; connect the tune to the ferrite stick with another patch, and provide power through either the AC adaptor or 9-volt battery. (I used a battery).

Here are C.Crane’s directions for how to use The Twin Coil Ferrite® AM Antenna Signal Booster with a portable radio:

Place the Tuner Control in a comfortable location relative to your radio. Place the Antenna Element a few feet away. If the Antenna Element is placed too close to the radio, it will cause noise on your radio.
Place the Ferrite Stick on top of the radio near the center. Placement will vary depending on where the internal AM antenna of the radio is located.
For testing purposes, tune your radio to any weak AM station. It is important that the station be weak so you can clearly detect the improvement in reception.
Rotate the Fine Tune control, it will click on and the red LED indicator light will come on. Turn the Coarse Tune control knob slowly and you will likely notice a change in reception at some point on the dial. Adjust the control knob until you notice the most improvement on your signal. Now you can use the Fine Tune control for further refinement.
Move the Ferrite Stick around the radio to find the position that affects the signal the most. This position is the “sweet spot”, or the best position. Again, adjust the Fine Tune on the Tuner Control for the best reception possible. (I used rubber band to hold the Ferrite Stick in place, but the unit comes with some double-stick foam tape to hold it in place.)
Now you can orientate the Antenna Element for best reception. In most cases, the Antenna Element does not have to be adjusted again. When radio noise is a problem, try rotating the Antenna Element in the direction which reduces noise to a minimum.

And The Twin Coil Ferrite® AM Antenna Signal Booster works like crazy! With same station on my CCrane Skywave SSB, it boosted signal strength from 3 bars to full scale. With my Tecsun PL-880, it increased signal strength from 11 to 38.

In my view, although The Twin Coil Ferrite® AM Antenna Signal Booster costs twice as much as the Terk AM Advantage and is more complicated to use, it is more than twice as effective in boosting medium-wave signals.

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Raddy RF75A Review – Pocket Radio with Interesting Bells and Whistles

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Radioddity Raddy RF75A

By Robert Gulley K4PKM

The RF75A is an interesting little radio which (currently) retails on Amazon for ~$53.00 in the States. It can also be purchased via Radioddity directly for $53–if you use this referral code, you can save $15 off a $65 purchase.

Before we get into specifics, two things are worth mentioning right off:

I was asked if I would be interested in reviewing this radio by our fearless shortwave listening leader, Thomas, and the copy I have was provided to me at no cost by Radioddity directly. (I have no other affiliation with them, but have recently purchased a GMRS mobile radio from them which I am looking forward to using when I finish my review of the RF75A.)
This is, as you will see from the photos I am including, a pocket radio, not to be confused with a tabletop radio or a small portable radio such as the CCRadio Skywave or similar radio. I mention this because invariably there will be folks who expect tabletop or portable quality from a radio about the size of a playing card. It is not going to happen!

Having those thoughts out of the way, the quick and dirty answer as to the quality of the radio is, I am impressed. For those who have not read anything related to my past experience with radios, I have been a shortwave listener since I was about 10 years old, and now in my early sixties. So, I have seen a fair number of radios in my time (speaking as an old codger, or is that curmudgeon?) and have even moved with the times to incorporate SDRs into my radio arsenal.

Each style of radio has its place, and a pocket radio is designed to be the ultimate in portability and space savings. As light as this shirt pocket radio is, it still manages to feel reasonably solid, and of course, it could be packed into anything one was taking along for a trip.

Size Comparison with Playing Card and Cell Phone Battery

The radio measures 2.5″ x 3.5″ x 1″. Playing card and cell phone battery for comparison.

Here are some specs from the manufacturer’s website (saving you my long-winded descriptions!):

APP Control SW Radio: Thanks to the app intelligent remote control and Bluetooth 5.0 features, you can enjoy the convenience of RF75A. With its intuitive user interface and powerful wireless capabilities, you can easily control your radio from your devices (support iOS, Android, and HarmonyOS systems).
Wider Reception Range: Listen to FM, VHF, AM, SW, and WB, and stay up-to-date with your favorite radio shows and music with this powerful multi-band receiver. RF75A has a wider range of shortwave frequencies compared to the RF750.
Automatic Scan and Manual Storage: You can save up to 396 stations, so you can easily access your favorite stations. Experience powerful sound and crystal-clear reception with its 9.85′ wire antenna.
Personal Music Player: Boost your music experience with this all-in-one outdoor audio system. With Bluetooth 5.0 feature, a 3.5mm earphone socket, and a TF card socket, you can easily connect to your personal audio devices and connect to your computer as a speaker.
Outdoor Companion: This one-of-a-kind radio is designed to be small and lightweight, making it ideal for travel and outdoor activities. Use the flashlight and SOS for emergencies.

What’s in the box?

1 x Raddy RF75A
1 x Storage bag
1 x Lanyard
1 x Wire antenna
1 x Type-C charging cable
1 x Earphone

Reception

I always like to start a radio review by either listening to AM stations first, or WWV time stations for checking out shortwave reception. In this instance I started listening to AM stations in the daytime to see what I could hear on a typical day (no storms nearby, early spring, etc.).

Living in a fairly remote area I was surprised it captured as many stations as it did, making me think the ferrite bar inside must designed well for such a small radio. Evening and nighttime listening brought in many of the usual stations with which we are familiar, particularly the so-called Clear Channel stations. What was more impressive were the many small stations I was able to pick up, not only at night, but early in the morning around 8 a.m.

Surprisingly effective Ferrite Bar

Side vide showing the magnetic wire wrap

One in particular caught my attention as I am quite certain I have never captured them before, was WHKY 1290, Hickory North Carolina. That’s a distance of about 285 miles, received in the morning. I am only about 50 miles from Cincinnati and cannot receive some of their smaller stations on any radio! Color me impressed!

Nighttime brought stations in from several thousand miles, as you would expect, yet I was likewise impressed with this little radio’s capabilities on AM.

FM

I confess to not being much of an FM listener, but I did tune around the band for FM stations to test its ability to “lock on” to signals (as indicated by a tiny red light) and to pick up stations from quite a good distance away with clarity and good sound.

This might be a good time to mention the quality of sound from the small 3 Watt(!) speaker and bass boost from the back. Again, this is not my Sangean 909 X2 with a large speaker, nor my CC Radio EP, but it has rather amazing clarity and volume capability for such a small radio. I cranked the volume up quite high with no distortion, and even though the speaker is small, the bass boost seems to round out the sound quite nicely, avoiding some of tinny sounding speakers common in such a small radio.

Weather

The radio has coverage of the NOAA weather radio stations and it surprised me with being able to receive 4-5 stations, more than I have gotten with most other radios. All but one of the signals were crystal clear, with the fifth having some noise, but still quite intelligible.

Air Band

This radio includes the air band frequencies and amateur 2-meter frequencies (30.000-199.975 MHZ). I am usually able to receive some signals, but I am quite far away from any local airports or repeaters, so my main reception is from CVG, Greater Cincinnati Airport. While the radio scans the air band frequencies, like any other radio, it is best to find local frequencies you want to hear and program them into memory so you are not wasting a lot of time scanning dead air (these are country specific). Likewise amateur repeaters or GMRS, marine, or public service channels would be best used in memory channels except when scanning for new frequencies.

SWL

Shortwave listening is very respectable, with frequency ranges between 4.750-21.850 MHz (it does not have SSB capability). Tuning can be accomplished by pressing and holding one of the directional tuning keys for about 2 seconds, a long press scans faster. A single press of either directional button will move the frequency increment based on the band/mode chosen.

The radio also features something I have come to really like: a pause button which works not only in music mode, but also when receiving regular radio signals, activated by a quick press of the power button. The frequency is held while pause is active, and then releasing the pause with a second quick press of the power button resumes with all your setting still active.

When comparing this with another radio it was particularly useful instead of having to turn the volume down like most radios. This feature is also nice for answering a call or other interruption, and you resume right where you left off.

Sound Effects, TF Card, Audio in, Bluetooth Usage and other Errata

I have not covered these features as they do not impact radio reception, but I mention them just for completeness. All of these features are available and can be read about in the user’s manual. I will mention the flashlight feature and the emergency siren features, as these are useful for portable operation. The light is quite bright, and the siren will hurt your ears if you trip it accidentally, especially more than once. Ask me how I know!

There is a sleep timer as well as an alarm clock function, with the sleep timer adjustable by default starting at 90 minutes. Most buttons have multiple functions depending on the mode employed, so reading the manual is important for some of these features. I was able to get up and running without reading the manual initially, but some features were functional only in certain modes, so eventually you will need the manual which can be downloaded from the Radioddity site.

The App

A bit of a novelty in this size and type of radio is the Apple/Android app available to control radio functions remotely through Bluetooth connectivity. I have to say, on Android at least, the app is beautiful and I wish more apps used such a clear color scheme and large controls. Your mileage may vary based on your preferences, but I like it!

The free Phone app on an Android phone. I like the crisp, clear layout and colors, and the intuitive design.

As to function, the app gives you more information than the radio screen, such as the Bandwidth, SNR, received signal strength and the volume setting in one display. As a side note, the radio can still be adjusted at the radio, and then changes are reflected in the app almost instantaneously.

Of course, the main use for the app is to operate remotely, and the controls are easy to use, including, most importantly, direct keyboard entry of frequencies! This is always the biggest drawback to small radios without a keypad. There are instructions for using the app, but for the most part the app is laid out so well you can control the radio pretty much intuitively.

Negatives –

Yep, there are a few. When tuning with a single press each time there is some soft muting – fortunately it does not last long, but it is there. The buttons also make a clicking sound, not too loud, but it is there. If something like that annoys you, be aware all the buttons make a mechanical click.

I have noticed on several occasions that the band/mode button may stick slightly and take you past where you want to go. Not a big problem, but it does happen now and again. Of course, this could just be my unit.

Also, naturally, the buttons are small. And while I did not have much of an issue even with fairly large fingers, there were times when I pressed the desired button but also hit the one below it. Not a problem for me, but again, if you have very large fingers you may find the radio a bit tricky to navigate in some places. (This only happened on the front buttons for me, the tuning buttons are adequately spaced for most anyone I think.)

The telescoping antenna is probably the weakest point on the radio – similar to most radios, really. It is thin and could be bent easily. I had no difficulties, but I always took care to raise it gently and watched where I was moving the radio around. Then again, I do that will all my radios with telescoping antennas. Just a heads-up to be careful.

Concluding Thoughts

I like this little radio, and will probably keep it in my car for those times when I might want to listen to the radio out and about, check the NOAA weather forecast, use the flashlight, or (hopefully never need) to use the siren. The battery seems to last a long time on a charge when using the radio – I cannot speak to the MP3 drain or a prolonged flashlight/siren drain, but under normal use it seems excellent. It uses a USB-C connection like my phone, so charging is not an issue for me. It will almost fully charge in an hour; the instructions say 2 hours.

Pocket radios certainly have their niche, and I think this one does quite well in that role. If you are in the market for such a radio, I think you will be pleased, especially for the price and the addition of the free remote-control app. 73!

Click here to check out the Raddy RF75A at Radioddity.

Click here to check it out on Amazon.com (affiliate link).

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Comparing the Watkins-Johnson WJ-8711 & WJ-8712 with TEN-TEC RX-340 & RX-331 receivers

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

The WJ-8711 & WJ-8712 vs. Ten-Tec RX-340 & RX-331 Receivers

by Paolo Viappiani, Carrara, Italy

In recent years, a renewed interest has grown in regards to the best HF receivers using “first generation” DSPs, typically the HF-1000/HF-1000A, WJ-8711/WJ-8711A and WJ-8712 models by Watkins-Johnson and the RX-340 and RX-331 models by Ten-Tec. Even today, the aforementioned receivers are considered among the best performers of all times; this is a well-deserved fame in the case of the W-Js, a bit less with regard to the units manufactured by Ten-Tec, a firm that once had a good reputation but that has been recently acquired by a new owner (who sold the old facilities by transferring the company and distorting the sales, support and assistance policies of the previous company [2]). I therefore believe that this article serves as a dutiful information for the readers who are potentially interested in these receivers.

A Bit of History

In the years between the last and the present century, two receivers very similar to each other in terms of design and structure were released almost simultaneously by Watkins-Johnson of Gaithersburg, Maryland [1] and by Ten-Tec of Sevierville, Tennessee [2]: the WJ-8711 (later upgraded to the A and A-3 versions and followed for a short period by the HF1000 and the HF1000A “civilian” versions [3]) and the Ten-Tec RX-340; both of them are shown in Figure 1.

Figure 1: The WJ-8711A (above) and Ten-Tec RX-340 (below). Notice the similarity of the front panels of the two radios.

The WJ-8712/WJ-8712A and the Ten-Tec RX-331 receivers were released by their respective manufacturers in that period also (the latter one was preceded by the RX-320 and RX-330 models). All these types were nothing more than “black-box” units, that in all respects corresponded to the WJ-8711A and to the Ten-Tec RX-340 receivers but that had not been provided with true front panels, as they were controlled by special hardware interfaces or from a PC, look at Figures 2 and 3.

Looking at the appearance of the WJ-8711/HF1000 receiver series and of the Ten-Tec RX-340 units, a relative similarity to each other is evident, and it has led to various speculations regarding the design of both devices.

One of the theories was revealed by James (Jim) C. Garland W8ZR of Santa Fe, New Mexico [4], about which he claims to have obtained information from a Ten-Tec employee directly. James claims that in 1991 the US Government Agency NSA (National Security Agency), which used to purchase numerous HF receivers for surveillance and interception, decided that the current cost of the receivers were too high and formed a special group in order to study how to obtain a possible price reduction.

At that time the high-end HF receiver market was dominated by a few manufacturers: Watkins-Johnson, Racal, Cubic, Rockwell-Collins and a few others, and Ten-Tec applied for joining the group.

Figure 2: The WJ-8712A (above) and Ten-Tec RX-331 (below). While the Watkins-Johnson model is two rack units high and half wide, the Ten-Tec develops less in height (only one rack unit) and more in width (standard 19” rack). However, both receivers are quite deep (more than 20”-50 cm.).

Figure 3: The Tmate unit of the WoodBoxRadio is shown here; it is one of the possible accessories which, together with a PC monitor, allow using the “black-box” receivers via an RS-232 interface.

According to the information provided by Jim Garland, the Watkins-Johnson and the Ten-Tec designers worked together for about one year in order to agree on the technical characteristics and guidelines of the “radio of the future” which must meet all the requirements that the NSA requested.

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A “knobs and switches” oldster investigates the SDRplay RSPdx . . . Wow!

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By Jock Elliott, KB2GOM

It is hard to imagine a less spectacular looking piece of radio gear than the SDRplay RSPdx. It is literally a black box. Aside from the printing on top of the box, the most exciting thing about the RSPdx are the two red plastic covers on the antenna connectors on the side. There are no switches, no knobs . . . you can’t do anything to it except connect an antenna (or antennas) on one side and a USB cable on the opposite.

But once you connect the USB cable to your laptop and fire up the SDRuno software (that you have previously downloaded and installed), you are now in command of a listening post that covers from 1 kHz to 2 GHz.

We’ll get to the important stuff in just a minute, but first a little background.

For an oldster retrocrank like me, a proper radio has knobs and switches . . . preferably a knob or switch for every job. Lately, however, I have noticed that a lot of DXers and ordinary listeners are reporting good success with SDRs – software-defined radios. So I started to wonder about them.

There are three elements to a software-defined radio like the SDRplay RSPdx: the SDR box itself, which is the part of the system that actually receives the radio signals; a Windows computer (laptop or desktop), which provides the command and control for the SDR; and whatever antennas are required to receive the signals that the listener would like to hear. And, just to be absolutely clear, you need all three elements for the SDR system to work at all.

With my curiosity about SDRs rising, I inquired of Thomas, SWLing’s Maximum Leader, whether SDRplay – one of SWLing Post’s sponsors – might like me to take a look at one of their SDRs. Their answer was an emphatic Yes, and I had an RSPdx in my hands just a couple of days later at no cost to me or the SWLing Post.

I have to admit I had some trepidation about the process of bringing the RSPdx online because any time you have three different elements from three different sources that must work together for a system to function properly, there is always the possibility that some of the elements might not “play well together.”

Installation is easy and fast. Connect the RSPdx to the computer using a USB A-male to B-male cable (which the user must supply; often called a printer cable), then connect the antennas using the appropriate cable. In my case, I connected an MFJ 1886 Receive Loop to the Antenna C connector and an off-center fed dipole to the Antenna A connector.

To SDRplay’s great credit, they have produced an excellent video for first-timers and folks not familiar with SDRs — https://youtu.be/Oj_-dOLVzH8 . I recommend watching it, perhaps a couple of times, before you get started.

When you first fire up the SDRuno software, you will see the main panel:

Click on the “RX” button, and the Receive panel will be displayed. After you slide it over, it will look something like this: