Category Archives: FM

Software Defined Radio Primer Part 1: Introduction to SDRs and SDR applications

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The new ELAD FDM-S3.

The following article originally appeared in the June 2018 issue of The Spectrum Monitor magazine:

SDR Primer Part 1: Introduction to SDRs and SDR applications

I author a radio blog known as the SWLing Post; as a result, I receive radio-related queries from my readers on a daily basis.  Among the most common questions are these:

“So, what is an SDR, exactly? Are these better than regular radios?”

and/or,

“I think I’d like to buy an SDR. Which one do you recommend?”

Great questions, both! But, before I address them, I must let the reader know that they are also “loaded” questions: simple enough to ask, but quite nuanced when it comes to the answers.

No worries, though; the following three-part primer sets out to address these questions (and many more) as thoroughly as possible. This first part of the primer will focus on the basic components of an SDR system. In part two, next month, we’ll look at affordable SDRs: those costing less than $200 US. In part three, we’ll take a look at pricier models and even include a few transceivers that are based on embedded SDRs.

But before we begin, let’s start with the most basic question: What is a Software Defined Radio (SDR), exactly?

Not your grandpa’s radio

Here’s how Wikipedia defines SDR:

“Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.”

Whereas your grandpa’s radio was all hardware––in the form of filters, mixers, amplifiers, and the like––SDRs are a mix of hardware and software. With the exception of tabletop transceivers and receivers with embedded software and systems (which we’ll discuss in part three of our investigation), SDRs typically take on a “black box” appearance: in other words, the radio looks like a simple piece of hardware with a minimum of an antenna port, a data port and many times there’s also some sort of LED or light to let you know when the unit is in operation. On some models of SDRs, there is a separate power port, additional antenna connections, power switch, and possibly some other features; however, “black box” SDRs often look like a nondescript piece of portable computer hardware––something like an external portable hard drive.

Why would you want an SDR?

Many of us have made it through life thus far without an SDR…so, why in the world should we want the use of one?  Below, I’ll list some of the most appealing reasons:

Bang-for-buck

The Airspy HF+ (top) and FDM-S2 (bottom). Photo by Guy Atkins.

By and large, SDRs are quite a value when compared to legacy all-hardware radios. For example, I wouldn’t hesitate to pit my SDRs––such as the $500 Elad FDM-S2 or $900 WinRadio Excalibur––against legacy receivers that cost two to three times their price. Indeed, my $200 AirSpy HF+ SDR will give many DX-grade ham radio general coverage receivers a real run for their money. They’re that good.

Spectrum display

SDR applications have a spectrum display which gives you a real-time view of a broad swath of the radio dial. Whereas you can tune to and listen to one frequency at a time with legacy receivers, SDRs allow you to view, say, the entire 31 meter band. With the spectrum display, you can see when signals come on or go off the air without actually being tuned in to them. You can tell what signal might be causing interference because you can see the outline of its carrier. Spectrum displays are truly a window––a visual representation––of what’s on the radio. Using legacy receivers now often makes me feel like I’m cruising the bands with blinders on. After becoming accustomed to having a spectrum display, there’s simply no way I’d want to be without at least one SDR in my shack.

Powerful tools

I like how clean the user interface is for this SDR application (SDRuno) window that controls the SDR’s frequency, mode, filters and notch.

SDRs usually afford access to a dizzying array of customizable filters, gain controls, noise blankers, digital signal processing (DSP), audio controls, and more. Being able to customize the SDR’s performance and listening experience is simply unsurpassed. In fact, it’s almost a curse for SDR reviewers like me––comparing two SDRs is problematic because each can be altered so much that identifying the best performance characteristics of one or the other becomes a real challenge. In other words, comparing SDRs is almost like comparing apples to oranges: even using a different application can enhance and thus alter the performance characteristics of an SDR.

Multiple virtual receivers

SDR Console makes managing multiple virtual receivers a breeze.

Whereas most legacy tabletop receivers allow you to switch between two VFOs (VFO A and B) some modern SDR applications allow for multiple independent virtual receivers––in essence, multiple sub-receivers. On my WinRadio Excalibur, for example, I can run three fully-functional and independent virtual receivers within a 2 MHz span. On receiver 1, I might be recording a shortwave broadcaster on 7490 kHz. On receiver 2, I might be recording a different broadcaster on 6100 kHz, and following a 40 meter ham radio net on 7200 kHz in the lower sideband.

Recording tools

SDR applications, more often than not, have functionality for making audio recordings of what you receive. Some, like the WinRadio Excalibur and SDR Console, actually allow for multiple simultaneous recordings on all of their virtual receivers.

SDR Console recording dialog box

Most SDR applications also allow you to make spectrum recordings, that is, to record not just one individual broadcast from one radio station at a time, but to record an entire broadcast band, all at once. Each recording can easily contain dozens of stations broadcasting simultaneously. Later, you open the recording and play it back through the SDR application. Recordings can be tuned and listened to as if they were live. Indeed, to the SDR application, there is no difference in using an antenna or using a recorded spectrum file; the tuning experience to the listener is also identical.

So imagine that propagation is stellar one evening, or there’s a global pirate radio event just when you’re going to be away from home: simply trigger a spectrum recording and do a little radio time travel tuning later. It’s that easy.

Constant upgrades

Both SDR applications and SDR firmware are upgradable from most manufacturers. In fact, I’ve found that the most affordable SDRs tend to have the most frequent upgrades and updates. Updates can have a positive impact on an SDR’s performance, can add new features, such as the ability to expand the frequency range or more filters or embed time stamps in the spectrum waterfall. It could be pretty much anything and that’s what’s so brilliant. As a user you can make requests; your SDR’s developers might, if they like the idea, be able to implement it.

So, what’s not to love?

Looking at all of these advantages of SDRs over legacy radios, it sounds like SDRs should truly suit everyone. But the reality is, they don’t. For some radio enthusiasts, SDRs do have some unfortunate disadvantages:

First, if you’re primarily a Mac OS or Linux user, and/or prefer one of these platforms, you’ll find you have much less selection in terms of SDRs and applications. While there are a few good applications for each, there are many more SDR applications for PCs operating Windows. Until I moved into the world of SDRs, in fact, I was a Mac OS user outside of work. At the time, there were only one or two SDR applications that ran on the Mac OS––and neither was particularly good. I considered purchasing a copy of Windows for my MacBook, but decided to invest in a tower PC, instead.

Second, one of the great things about legacy radios is that with just a radio, a power source, and an antenna, you’re good to go; travel, field operations, and DXpeditions are quite simple and straightforward. SDRs, on the other hand, require a computer of some sort; when traveling, this is typically a laptop. I’ve spent several summers in an off-grid cabin in Prince Edward Island, Canada. My spot is superb for catching DX, and there’s no RF interference, so I love making spectrum recordings I can listen to later. Problem is, powering so many devices while off-grid is an art. Normally, my laptop can run off of battery power for hours, but when the laptop also provides power to an SDR and portable hard drive, it drains the battery two to three times faster.

The ELAD FDM-DUOr (receiver).

With this said, keep in mind that there are fully functional tabletop radios (like the Elad FDM-DUO and FDM-DUOr) that are actually SDRs, providing an easy way to bypass this concern.

Finally, there are simply some people who do not care to mix PCs and radio. I’ve a friend who’s a programmer, and when he comes home to play radio and relax, the last thing he wants to do is turn on a computer. I get it––as a former programmer, I used to feel that way myself.  But the world of SDRs lured me in…and now I’m a convert.

Scope of this primer series

The world of SDRs is the fastest growing, most dynamic aspect of the radio world. Because of this, I simply can’t include all SDRs currently on the market in this primer.  Let’s face it: there are just too many, and it is beyond the scope of this article to try to cover them all. Instead, I’ve curated my list, by no means comprehensive, to include a selection of the most popular and widely-used models.

I’ll be focusing on SDR receivers unless otherwise noted. In Part Three, I’ll call out some popular SDR transceivers. Additionally, I’ll bring my attention to bear on the “black box” variety of SDRs.

This primer is long overdue on my part, so I’ll provide answers to the most frequent questions I receive. But though this primer is in three parts, it barely scratches the surface of the vast world of SDRs.

Thus far we’ve defined an SDR and discussed its advantages and disadvantages.

Now, let’s take a closer look at what you’ll need to build a station around an SDR.

Assembling an SDR station

Guy Atkins’ laptop running HDSDR software in his SUV; the receiver is an Elad FDM-S2. (Photo: Guy Atkins)

In truth, most of you reading this primer will already have everything you need to build a listening post around an SDR. Understanding the components of the system in advance, however, will put you in a better position to get on the air quickly with an SDR that suits your needs best. Let’s discuss this component by component.

A computer

By virtue of reading this primer now being displayed on your screen, unless you’ve printed it out, I’m guessing you have access to a computer of some sort.

SDRs are really quite flexible in terms of computer requirements. SDRs are compatible with:

  • A desktop PC running the Windows operating system
  • A laptop PC running the Windows operating system
  • A desktop Apple computer running MacOS and/or Windows
  • A laptop Apple computer running MacOS and/or Windows
  • A tablet or smartphone computer running Android or Windows
  • A Raspberry Pi/Beaglebone (or similar budget computer) running a Linux distribution

If SDRs are compatible with so many computer operating systems and configurations, then why would you worry about which ones to choose?

As I mentioned earlier most, but not all, of the SDR applications on the market are only compatible with the Windows operating system. If you want the most out-of-the-box, plug-and-play SDR options, then you should plan to use a Windows PC. If you’re a MacOS user, fear not. Modern Apple computers can support Windows—you simply purchase a copy of Windows and set your system to boot as a Windows machine (assuming you have the storage space for a dual boot).

Secondly, processing speed is certainly a factor: the faster, the better. While you can use an Android/Windows tablet or a Raspberry Pi to run an SDR, they often don’t have features like multiple virtual receivers, wideband spectrum recording capabilities, and large fluid waterfall displays due to the simple lack of processing power. My guess is that by 2023, however, tablets and budget computers will have ample processing power to handle most, if not all, SDR functions.

Finally, if you plan to make spectrum recordings, especially wideband ones (2 MHz, plus), you need both a snappy processor and a high-capacity hard drive with a decent write speed. This is the reason I now have a desktop PC at home for spectrum recordings: I can use a very affordable SATA drive as a storage device, and the write speed is always more than adequate. My OS and SDR applications run on an SSD (solid state drive) which is very fast.  All of my recordings are saved to internal and external 4TB+ hard drives. Happily, I’ve never had a hiccup with this system.

An SDR application

SDRuno has an attractive user interface comprised of multiple adjustable windows.

Wait a minute…am I suggesting you choose an SDR application before you choose an SDR?  Why, yes, I am! You cannot use an SDR without an SDR application, but, with only a few exceptions, you certainly can use an SDR application without an SDR attached.

Unlike a legacy hardware radio, you can essentially test drive an SDR by downloading an application (almost always free) and then downloading a test spectrum file. Most SDR manufacturers will have all of this on their download page. Simply install the application, open the spectrum file, et voila! You’re now test driving the SDR. Your experience will be identical to the person who originally made the spectrum recording.

The WinRadio Excalibur application also includes a waterfall display which represents the entire HF band (selectable 30 MHz or 50 MHz in width)

I always suggest test driving an application prior to purchasing an SDR.

While all SDR applications have their own unique layout and menu structure, almost all have the same components, as follows:

  • a spectrum display, which gives you real-time information about all of the signals within the SDR’s frequency range;
  • a waterfall display, which is a graphical representation of the signals amplitude or strength across the SDR’s frequency range displayed over time;
  • filter controls, which help you adjust both audio and signal widths;
  • mode selections, which allow you to change between modes such as AM, SSB, FM, and digital;
  • a signal meter, which is typically calibrated and resembles a traditional receiver’s “S” meter;
  • a frequency display for the active frequency;
  • VFOs/virtual receivers, which may have real estate allocated on the display;
  • a clock, which displays the time, possibly as both UTC and local time (note that many SDR apps also embed time code in waterfall display);
  • memories, where you can store a near-infinite number of frequencies (and some SDR applications allow you to import full-frequency databases); as well as
  • other controls, such as squelch, gain, noise blanker, DSP, notch,etc.

After you’ve become comfortable with one SDR application, moving to another can be a little disorienting at first, but the learning curve is fairly short simply because most have the same components.

Types of SDR applications

SDR applications usually fit one of three categories: proprietary app, free third-party apps, paid third-party apps, and web browser based apps. (Assume each application runs on Windows unless otherwise noted.) Let’s take a look at each.

Proprietary SDR applications

Proprietary apps are those that are designed by the SDR manufacturer and provide native plug-and-play support for the SDR you choose. Proprietary apps give priority support to their own SDR, but some are compatible with other SDRs––or can, at least, read spectrum recordings from other SDRs. Most popular SDRs have a proprietary application. Here are examples of a few proprietary apps:

  • WinRadio App for the WinRadio/Radixon line of SDRs
  • Perseus Software Package for the Microtelecom Perseus
  • SDR# App for the AirSpy line of SDRs
  • SDRuno App for the SDRplay series of SDRs
  • FDM-SW2 App for Elad SDRs
  • SpectraVue App for the RFSpace line of SDRs
  • SmartSDR App for FlexRadio SDR transceivers

Free third party SDR applications

Free third party applications are incredibly popular and some even offer performance and feature advantages over proprietary applications. Third party apps tend not to be associated with any one particular manufacturer––SDR# being a noted exception––and tend to support multiple SDRs. I’m a firm believer in supporting these SDR developers with an appropriate donation if you enjoy using their applications.

  • HDSDR is a very popular application that supports multiple SDRs and spectrum file formats. The layout is simple and operation straightforward.
  • SDR Console is a very powerful and popular application. Like HDSDR, it supports multiple popular SDRs. It is my SDR application of choice for making audio and spectrum recordings.
  • SDR# runs AirSpy SDRs natively, but also supports a number of other receivers including the venerable RTL-SDR dongle.
  • Linrad (Linux)
  • SdrDx (MacOS and Windows)
  • Gqrx SDR (Linux)
  • SDR Touch is a popular SDR application for Android devices (Android)
  • iSDR is one of the only SDR applications currently available for iOS devices. Its functionality is somewhat limited. There are other SDR applications in the works, but at the moment these are in development stages only. (iOS)

Paid third-party apps

Paid third-party apps represent a tiny fraction of the SDR applications available on the market. Indeed, at time of posting, the only one I know about that’s currently on the market is Studio 1, which has been the choice for those looking for an alternative application to the Microtelecom Perseus Software Package.

Web browser-based  SDR applications

The KiwiSDR browser-based application

This is, perhaps, one of the newest forms of SDR applications. While a number of SDR applications (like SDR#, SDR Console and the Perseus Software package) allow for remote control of the SDR via the Internet, there are actually few applications that are purely web browser-based. At the time of this writing, the only one with which I’m familiar is the KiwiSDR application, which allows both the SDR owner and (if set up to do so) anyone else in the world to operate the SDR as if they are at the SDR’s location. In fact, the KiwiSDR only has a web browser-based application, there is no downloadable application. It will allow up to four simultaneous users, and the experience of using a KiwiSDR locally or globally is nearly identical. If you would like to use a KiwiSDR, simply visit http://SDR.hu or https://sdr.hu/map and choose a remote location.

[Note that if you like web-based SDRs, I highly recommend checking out the University Twente WebSDR located in the Netherlands.]

Choosing an SDR

In Parts Two and Three of this primer, we’ll take a closer look at some of the SDRs currently on the market; prices range anywhere from $15 to $6,000. As you can imagine from such a price range, these are not all created equally.

But first, ask yourself what your goal is with your SDR. Do you want to monitor ham radio traffic? How about aviation communications? Follow pirate radio? Listen to a range of broadcasters? Pursue radio astronomy? Is your dream to set up a remote receiver?

Whatever your flavor of radio, you’ll want to keep some of these needs in mind as you explore the SDR options available to you.

Budget

Photo by Kody Gautier

Be honest with yourself: how much are you willing to spend on an SDR? While entry-level SDRs can be found for anywhere from $15-50 US, a big leap in performance happens around the $100 mark. If you’re looking for benchmark performance, you may need to appropriate $500 or more. Whatever you choose, keep in mind that SDRs are only as good as the antennas you hook up to them. Set aside some of your budget to purchase––or build––an antenna.

Compatible applications

As mentioned above, not all SDRs are compatible with anything beyond the OEM/proprietary application. If you have a choice third-party application in mind, make sure the SDR you choose is compatible with it.

Frequency range

If you want an SDR that covers everything from VLF/longwave up to the microwave frequencies, then you’ll need to seek a wideband SDR. Each SDR manufacturer lists the frequency ranges in their specifications sheet. It’s typically one of the top items listed. Modern wideband SDRs can be pretty phenomenal, but if you never plan to listen to anything above 30 or 50 MHz, for example, then I would advise investing in an SDR that puts an emphasis on HF performance. Check both specifications and user reviews that specifically address performance on the frequencies where you plan to spend the bulk of your time.

Recording and processing bandwidth

The new SDRplay RSPduo can display up to 10MHz visible bandwidth (single tuner mode) or 2 slices of 2MHz spectrum (dual tuner mode)

If you plan to make either audio or spectrum recordings, or if you plan to monitor multiple virtual receivers, pay careful attention to an SDR’s maximum recording and processing bandwidth. This bandwidth figure is essentially your active window on the spectrum being monitored. Your active virtual receiver frequencies will have to fall within this window, if you’re making simultaneous recordings. In addition, this figure will determine the maximum bandwidth of spectrum recordings. Some budget SDRs are limited to a small window––say 96 kHz or less––while others, like the Elad FDM-S3, can widen enough to include the entire FM broadcast band, roughly 20 MHz!

Portability

AirSpy’s HF+ was introduced late 2017. Don’t be surprised by its footprint which is similar to a standard business card to its left–this SDR packs serious performance!

If you plan to take your SDR to the field or travel with it, you’ll probably want to choose one that doesn’t require an external power supply. Most late-model SDRs use the USB data cable to power the unit.  This means you won’t need to lug an additional power plug/adapter or battery. Still, many professional grade SDRs require an external power supply.

Recording features

If you plan to make spectrum recordings, determine whether you have many options to set the unit’s processing bandwidth. Some SDR applications have robust recording functionality that allows for both spectrum and audio recordings, including advanced scheduling. Some applications don’t even have audio recording or spectrum recording capabilities. Test drive the application in advance to check out their recording functionality. Of course, if recording is your main interest, you’ll also want to set aside some of your budget for digital storage.

Know your goal!

If your goals are somewhat modest––perhaps your budget is quite low, you simply want to familiarize yourself with SDR operation prior to making a bigger purchase, or you only want to build an ADS-B receiver––then you might be able to get by with a $25 SDR dongle. If you plan to use your SDR as a transceiver panadapter during contesting, then you’ll want to invest in a unit that can handle RF-dense environments.

Identify exactly what you’d like out of your SDR, and do your research in advance. Note, too, that many popular SDR models have excellent online forums where you can pitch specific questions about them.

Scoping out the world of SDRs

Three benchmark receivers in one corner of my radio table: The Airspy HF+ (top), Elad FDM-S2 (middle) and WinRadio Excalibur (bottom).

Now that we have a basic grasp on what SDRs are, what components are needed, and what we should research in advance, we’ll look next at some of the SDR options available to us. In Part Two, we’ll look at budget SDRs; those under $200 US in price. In Part Three, we’ll survey higher-end SDR packages.

Stay tuned for more in Part Two (October–click here to read) and Part Three (November–click here to read)! I’ll add links here after publication.

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A review of the Sangean HDR-14 portable AM/FM HD radio

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Late last year, we learned that Sangean was planning to introduce a small portable HD radio to their product line: the Sangean HDR-14. Readers were excited about this release––indeed, I’ve received more inquiries and comments from readers about this radio than about any other HD radio.

While there have been numerous portable FM HD radios on the market over the years, there have been very few compact HD portables that can also pull AM HD signals from the ether. Shortly after Sangean made their announcement that the HDR-14 was forthcoming, I contacted them and requested a review unit. They sent me a review sample from the first production run in May.

Due to my exceptionally busy schedule this summer, it’s taken me longer than I’d like to  be able to write up a complete review. On the plus side, while I’ve not had a chance to sit down and write, I have had time to listen; thus I’ve had more on-the-air time with the HDR-14, with the result that my review is built on nearly three months of use.

Initial impressions

Size comparison: Sangean HDR-14 (left) and the C. Crane CC Skywave SSB (right)

The HDR-14 has a practical AM/FM portable radio design: the front panel features a backlit display, speaker grill, power button, memory preset buttons and a few other buttons to control essential functions like tuning, HD mode/channel selection, band, and information display toggle.

Like most similar Sangean radios, the chassis is a hard gloss plastic finish, while the front panel is mostly matte. The buttons are raised and have a pleasing tactile response.

On the left side of the radio you’ll find a coaxial power port (5VDC with a positive tip), volume wheel and headphones jack. I do wish Sangean had used a standard micro USB port, but their alternate choice might be be a result of the fact that USB power supplies are so RF noisy…? This is, however, mere speculation on my part.

On the right side, the only feature is one mechanical key lock switch––a bonus for me, as I prefer mechanical key locks over push buttons.

On the back of the radio you’ll find the usual silk-screened product specifications and model information. You’ll also find the large battery compartment cover which easily slides open to reveal positions for three AA cells.

The telescopic antenna is sturdy and about twenty-five inches in length, fantastic for FM radio reception.

One unique feature of the HDR-14 is that it doesn’t have a tilt-out stand on the back, rather a foot that swings out from the bottom/base of the radio. The foot gives the HDR-14 excellent stability while standing up, say, on a night stand next to the bed. Brilliant addition, Sangean!

Features and specifications

For such a compact portable, the HDR-14 sports a compliment of features:

  • HD Radio digital and analog AM / FM-Stereo reception
  • 40 Memory Presets (20 FM, 20 AM)
  • PAD (Program Associated Data) Service
  • Support for Emergency Alerts Function\
  • Automatic Multicast Re-Configuration
  • Real Time Clock and Date with Alarm and Sleep Function
  • 2 Alarm Timer by Radio, Buzzer
  • HWS (Humane Wake System) Buzzer and Radio
  • Snooze Function
  • Information Display for Channel Frequency, Call Sign, Radio Text, Audio Mode, Service
  • Mode, Signal Quality and Clock Time
  • Easy-to-Read LCD Display with Backlight
  • Low Battery LED Indicator
  • I/O Jacks: DC In, Headphone and HD / FM Rod Antenna

The clock and alarm features make the HDR-14 ideal for travel. Sangean’s “Human Wake System” is one of the best wake up alarm systems I’ve ever used on a radio: the buzzer alarm sound will slowly increase in volume for 1 minute, then stop for one minute of silence, and repeat up to one hour. Of course, this will wake most of us on the first go. If not, it’s patiently persistent, but a gentle way to wake:  I like this.

The internal speaker is well balanced though it lacks any notes of bass. Still, music is quite pleasing, and the spoken word sounds brilliant and clear. Note that my expectations for audio fidelity are always fairly low from radios in this size class (although the Sangean  WR-7 showed me that compact radios are capable of amazing fidelity).

Operation

Tuning the radio and storing frequencies to memory are each straightforward and simple.

Keep in mind, however, that the Sangean HDR-14 can receive both AM and FM radio in analog and HD. On either band, if you tune to an analog station with accompanying HD channels that can be received, the HD Radio logo will flash on the display, indicating that the signal is blending from analog to digital. Once the radio locks onto the HD signal, the HD Radio logo on the display will cease flashing and appear steady.

Saving a station to a memory is simple: 1) tune to a frequency, use the page button to select the desired memory page of five presets; 2) press and hold the button where you would like to store the frequency, and when you hear a beep, the station has been stored. If you chose, for example, the third page and first memory position, “31” (indicating “page 3” and “memory 1,” respectively) will appear on the top line of the display. After entering your presets, you can then recall a station by selecting a page and simply pressing the preset.

The HDR-14 does have a useful “HD Seek” function that searches for HD signals automatically. In addition, there is an HD Auto Preset System that will scan the band for HD signals, then auto-store them in memory presets according to their signal strength. The first memory on the first page will be the strongest station received.

If the HDR-14 acquires an HD station that multicasts (and in my market, most do), the display will note “HD1,” “HD2,” or “HD3,” based on the number of multicast HD signals per broadcaster. You can flip through these with the tune up/down buttons once the display indicates multicast signals.

The HDR-14 also features an alpha-numeric RDS system which makes identifying the station and even their programming/music quite easy. I find that the RDS decode is quite good: it works on even marginal FM signals.

Performance

The last Sangean HD radio I reviewed was the HDR-16, and I was impressed by its performance. As you can imagine, my hope was that the HDR-14 would pack the HDR-16’s performance in a smaller package…So, did it?

Let’s just say it comes quite close.

The HDR-16’s analog AM broadcast band performance is, overall, better than that of the HDR-14. The HDR-14 isn’t poor, but its noise level is slightly higher than the HDR-16’s. I can’t say I’m disappointed with the HDR-14’s analog AM performance, however; it’s just what one would expect. I do wish it had impressed me.

I’ve only received one AM HD signal with the HDR-14, so I can’t comment on the AM HD performance other than to say I was impressed with the steady HD lock. I listened to WWFD in Germantown, MD:  I could receive the station both day and even at night when power output was decreased dramatically. I find that AM HD sort of boggles the mind; it’s odd listening to a clear, static-free signal on the AM dial.

Click here to view on YouTube.

I’ve had several SWLing Post readers tell me they were impressed with the HDR-14’s ability to acquire AM HD signals. One reader added that it’s the best he’s ever used…wow! As I travel this year, I hope to snag a few more AM HD signals myself.

The HDR-14 is a very sensitive FM analog receiver. I find that I can receive all of my benchmark local and distant analog FM stations. The HDR-14 seems to be every bit as good as the HDR-16 in terms of sensitivity.

One caveat is that when I tune to an FM analog signal which happens to be adjacent to a strong FM station, sometimes the strong adjacent station bleeds into the audio. FM selectivity isn’t as good as the HDR-16.

In terms of FM HD performance, you might recall that in my review of the Sangean HDR-16, I mentioned that one of my benchmark distant HD FM stations is WFAE HD2. WFAE’s transmitter is just over one hundred miles from my home shack, and I’m well outside even the the fringe reception area. I’m pleased to note that, on more than one occasion, from my porch, I’ve gotten a reliable HD lock on WFAE with the HDR-14. I’m convinced that when the leaves fall off the trees this fall (they do attenuate signals) reception will be fairly near to reliable.

Listening to the HDR-14 from a hospital room.

While waiting for a block of time to pen this review, I’ve spent a lot of time tuning to FM HD signals in a least five different urban and regional markets in two countries. And I can say I’m very impressed with reception; the HDR-14 seems to snag every available HD signal.

Summary

Every radio has its pros and cons. When I begin a review of a radio, I take notes from the very beginning so that I don’t forget some of my initial impressions. Here is the list I formed over the time I’ve spent evaluating the HDR-14.

Pros:

  • Excellent overall FM Analog and HD performance
  • Excellent AM HD reception (a stand-out for pocket sized HD receivers)
  • 40 memory presets
  • Built-in speaker has first-rate fidelity for spoken word and music (see con)
  • Uses standard AA cells
  • Excellent build quality
  • Gentle but persistent alarm
  • Useful swing out stand for bedside listening and alarm usage
  • Compact form factor, ideal for travel

Cons:

  • AM analog performance is acceptable but not for weak-signal work
  • FM Analog selectivity is mediocre, some strong adjacent station bleed-through
  • Built-in speaker lacks bass response, so not optimal for all music listening (see pro)

Conclusion

While I have mixed feelings about digital radio in general––but especially In-band on-channel (IBOC) HD radio––I do love exploring all that over-the-air radio has to offer. Like it or not, HD radio is a part of that landscape for the foreseeable future.

HD Radio has opened up a few alternative music stations that otherwise I’d never have discovered in my local market. In addition, I find that NPR and public radio stations often multicast commercial-free talk, jazz, and classical music, which makes HD Radio a worthy addition at home and while I travel. In large urban markets, HD Radio certainly increases the number of available commercial options sometimes by a factor of two or possibly more.

If you like chasing AM and FM HD signals, you’ll be very pleased with the HDR-14. It’s first rate, and I recommend it.

The Sangean HDR-14 RDS display (Photo: Thomas)

I’ll close by adding that I continue to be impressed with Sangean as a company.  They’ve always been one of the quality leaders in the portable radio marketplace, and still make products with the radio enthusiast in mind––something of a rarity these days. I always look forward to seeing what they’ll come up with next!

The Sangean HDR-14 can be purchased at a number of retailers including:

Click here to check out the Sangean HDR-14 on Sangean’s website.

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Credit card radios: Paul seeks info about the “SW One-Station Radio Clip T2”

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The Sony SRF-201

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

On a recent visit to London’s Design Museum, I was thrilled to see a number of very interesting radio designs and models, some of which were familiar, and others I had never seen before.

Two which caught my eye were tiny Sony models from the mid 1980s.

The Sony FM RADIO SRF-201

One – the Sony SRF 201 -seems to be a little more well-known, and I’ve found plenty of information about it online, including some for sale, although it seems that the internal battery in most models is shot.

The SW One-Station Radio Clip T2

The other, which I’ve not found much about yet, and am hoping you or your readers might help with, seems to be known as ‘SW One-Station Radio Clip T2‘. It looks as though it might be a branded/promotional model for Radio Tampa, and seems to be pre-set to, or allows tuning on, shortwave between 3.945/6.115/9.760 MHz. Possibly this one is more recent than the 1980s, looking at the earphones.

I’m having trouble finding much online about the second radio, and wondered if you could help shed some light on it? I can’t even find a ‘Radio Tampa’!

Unfortunately, while the museum has great iPads at each section with some more information, the unit at the Sony section was not functioning!

Post readers: If you can shed some more light on the SW One-Station Radio Clip T2, please comment!

Thanks for sharing this, Paul. I have a soft spot for credit card radios since I used to sneak one into my 5th grade class and listen to FM stations. Somehow, I never got caught!

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A review of the Tecsun R-9012 shortwave radio

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

A review of the Tecsun R-9012

by Laurence Neils

I have cheap radios. I can’t really justify buying more expensive ones given how much time (not all that much) I spend listening to the short wave broadcasters. The consequence of this is that, when I do listen to shortwave stations, I have the rather standard ultraportables to listen on.

My go-to radio is the Tivdio V-115, which has pulled out quite nice reception for me, and offers several functions I like a lot. However, it was missing one that interested me the most: analog or analog-like tuning. If I want to listen to something, I either have to know its frequency and try it, or I have to let the radio do an automatic scan. While it’s quite good at pulling out stations and letting me hear them, it can take a few minutes to do a full scan, and canceling it doesn’t result in the part scanned so far to be stored. Very few stations I am interested in hearing are convenient to jump into several minutes after they start (my interest is in spoken content rather than music, and neither news nor stories make a ton of sense if the introductory information was not heard).

From a recommendation here on the SWLing Post, I chose to purchase a Tecsun R-9012 radio to help me do a convenient scan, which is useful because it allows me to find stations without knowing their frequency, and leaves me to not remember all seventy frequencies a certain broadcaster is using this year.

Physical Description

When I bought my Tecsun R9012, it arrived quite quickly from Amazon. It included a short manual, whose contents could be loosely paraphrased as “insert batteries and turn on”. Other than that, the radio is all that’s there.

The R9012 is relatively small, but not as thin or compact as the Tivdio, which will be my main comparison unit for this review. It is your basic rectangle form factor, and about the size of the small tape recorders that were the last to be phased out for portable recorders. It would be easy enough to put this in a backpack, jacket pocket, or glove compartment, but you have no chance comfortably fitting it into a standard pocket. On the back, there is a flip-out kickstand that can hold the radio at about thirty degrees from horizontal and the battery compartment. This radio is powered from two AA batteries.

The right side of the R9012 contains the analog tuning knob, which I will discuss quite a bit later, and the power switch, which is not connected to anything else (not integrated into the volume knob or mode selector).

The left side gives you a 3.5mm audio out jack. This supports all the headphone types I’ve tried. One benefit of this radio is that headphones with integrated microphones, such as the ones that come with the iPhone as well as various sets that are intended for phone use, will work with it. Some other radios won’t work well with that type of headset. The Tivdio, for example, will play through the headphones but forgets to turn off the speaker if there is a microphone on them, making the headphones pretty much pointless.

Next to that jack is a power port, supposedly to recharge the batteries. A connector for this is not included, nor do they seem to sell one. I suppose the theory is that you might already have a suitable one in that box of old cables we all have, but I can’t see this as a particularly useful feature given the RFI you’ll get if you connect a radio directly to the mains to recharge. Above the ports is the volume knob, which is a very basic analog one, and then the wrist strap, which is integrated into the case. There doesn’t seem to be a way to remove or change it, should you desire that.

On the front of the radio, the speaker takes up the left half. This is fine for standard listening, but don’t expect wonders of audio fidelity. On the right half, there is the twelve-position mode switch (from left to right, FM, MW, SW from low to high frequency) and the tuning display.

FM performance

The Tecsun has a standard FM function, with stated coverage from 76 to 108 MHz. This is the leftmost position on the mode selector. The band is not divided into multiple switch positions, meaning that stations will be relatively packed into dialing space when compared to shortwave, which is spread across ten bands.

I didn’t buy this radio to use it for FM. I have very little interest tuning for FM stations. Some people may enjoy the experience of manual tuning for a station they can locate quickly, but I’m not one. I can easily type the frequency I want on my Tivdio, and I intend to keep doing that for FM. I mostly intended to test FM performance on the R9012 because I was curious to see whether there would be anything audible in the 76-87 MHz section. I know that our TV standards have switched off using analog audio, so I assumed there would be nothing, but I’d never formally put that to the test.

FM on the R9012 has problems. In fact, it has a lot of problems. Among other things, the FM process on this radio doesn’t seem to have a very good idea where things are. I’d be tuning through looking for some station and I’d find it…only to see that I was in a completely foreign part of the spectrum where that station had no business being. It seems that, unless you’re very focused in on a station, the R9012 is liable to pick up some other broadcast and layer them on top of each other. Never mind that the broadcasts have nothing to do with each other and aren’t anywhere near each other on the band. If you have a specific station you want, you can tune to it and have no problems. If you want to see what’s there, you’ll have a very fun time listening to stations that you might want to listen to, only to find that that was an image, you’ve lost it now, and you can’t find it again.

Sometimes, I managed to find a part of the spectrum that gave me three different images simultaneously. Ironically, the broadcast I intended to use as my landmark, the local classical music broadcast, which is located very close to the middle of the FM spectrum, was strong enough or at a coincidental frequency that I identified images of it at six different places on the scan, in addition to where it should be. So I got my answer about 76-87 MHZ. According to the R9012, there’s a lot of signal there. It’s just coincidence that it sounds exactly the same as standard FM broadcasts with extra static.

FM performance gets worse: this radio is extremely sensitive to location.

In order to get nice reception, you have to have the radio in a good position. This seems to be completely random. Standing up so the antenna lies flat on the top, but is not extended produces almost silence. Lying down so the antenna is touching the table (not a metal table) or chair (not a metal chair) causes most signals and images to come through quite clearly. Extending the antenna to medium length helps reception. Extending it all the way introduces a lot of interference. On FM, volume also changes a lot. We may reasonably expect for the signal to change if we connect something conductive to the antenna by, say, touching it with our conductive fingers. Maybe reception will get more static, or maybe it will in fact improve. What we don’t expect is for the broadcast to switch from comfortable volume to let’s see if we can get you some tinnitus volume. Unfortunately, that’s sometimes what happens on FM if you touch the R9012’s antenna. Or tilt it a bit in the wrong direction. This doesn’t seem to happen much if it is tuned onto a station, but if it is anywhere in the middle or if there’s some static, the volume change is very noticeable, in that it makes you want to get the radio off as soon as possible.

In summary, this radio just can’t really do FM. If your other radios are broken, you’ll be fine by using this, but don’t buy it if you intend to do FM things.

Mediumwave performance

The MW frequencies are mostly there, with stated specs including from 525 to 1610 kHz. While there are broadcasts between 1610 and 1710 KHZ, that’s not a ton of the spectrum. I don’t have much interest in MW. I tested the radio’s performance, and it seems fine. Strong stations come in loud and clear. Stations that have low broadcast powers are easy to tune in. I was able to get some skywave MW in here as well, but I really don’t have any interest in that. I was able to verify, however, that the terrible effects that plague FM performance don’t appear on MW. I got no images of distant stations, no rapid volume switches, and the position of the radio doesn’t seem to affect MW reception all that much. Perhaps this is due to the different antenna that most radios employ in tuning MW. However, the manual doesn’t say whether this radio has such an alternative antenna and I haven’t gone to the effort of disassembling it to find out.

Shortwave performance

Once again, the crazy stuff seen on the FM band doesn’t appear during shortwave listening. I was able to tune in quite a few stations, although this probably isn’t a DX-capable device unless you’re willing to go out into RFI-free areas. That sounds enjoyable, but it’s not really my thing. When I got signal, it came in quite clearly. I got very little interference from the device itself, although it does seem quite susceptible to RFI from power lines. Of course, so is everything else, but if you put its antenna closer to a line, you’d know it.

Frequency coverage

Shortwave is covered in ten bands that allow access to the more populated areas of the spectrum, but have many gaps. Certain descriptions claim that the radio has coverage from 3.90 to 21.85 MHz. This is so misleading I’d be willing to call it a lie. The actual ranges are as follows:

  • SW1: 3.7 – 4.10Mhz
  • SW2: 4.75 – 5.06Mhz
  • SW3: 5.95 – 6.20Mhz
  • SW4: 7.10 – 7.30Mhz
  • SW5: 9.50 – 9.90Mhz
  • SW6: 11.65 – 12.05Mhz
  • SW7: 13.60 – 13.80Mhz
  • SW8: 15.10 – 15.60Mhz
  • SW9: 17.55 – 17.90Mhz
  • SW10: 21.45 – 21.85Mhz

So what if most signals are in there somewhere? Those gaps are very large. For example, the only broadcast frequency for WWV that would be covered on this set is the 5MHZ one. 10, 15, and 20MHZ are all located in various gaps on the bands.

This turned out to be quite annoying. I know that these are standard areas of the spectrum, in which people place a preponderance of broadcasts, but the fact remains that a lot of broadcasts occur between the bands on this set. I checked the A18 shortwave schedule to identify how crazy I was. Of the 5530 broadcasts that were listed between the limits of 3.90 to 21.85 MHZ, 1870 of them or 33.8% of the total, are outside the range of this set.

It strikes me that the largest band on this radio covers only 500 kHz of space, whereas the smallest gap between bands covers 750 kHz. In many cases, bands cover only 100 kHz of bandwidth. While I guess it’s better that they’re there rather than their being completely absent, perhaps some effort could have been done to open that up a bit more. I quickly analyzed where missing signals were, and if Tecsun could extend the 5.95-6.20 MHz band down to 5.8 MHz, 7.10-7.30 up to 7.60 MHz, expand the 9.5-9.9 band, and give an extra 50 kHz to the 11.65-12.05 band, most of the missing spectrum, nearly a thousand broadcasts, would be brought back into coverage. This could be done and still keep the maximum band width at 500 kHz. Therefore, as they didn’t seem to feel this an important issue, it falls to me to consider it so.

Manual tuning

So I bought this to tune manually. It stands to reason that I should review how well it does that.

The analog dial is on the right, and protrudes outward. Once again, the knob does its job, but not all that well. It was very easy to use this to pan through the spectrum and pick up stations, but the wheel doesn’t make it all that easy to do so quickly. You have to turn it by grasping, as the wheel has a fair bit of resistance. I don’t doubt that this feature helps to keep from knocking it off frequency, but you have to use two fingers to rotate freely, and that slows the process down. Meanwhile, the wheel has a rather disconcerting way of stopping, where the wheel seems to have hit an obstruction. However, this essentially increases the resistance, rather than feeling like a barrier. It’s noticeable, but it feels like something’s blocking the turning mechanism, rather than that the mechanism has reached its limit. Actually, it is possible to keep turning the dial, which I assume will eventually damage something, but if you’re not used to how it feels, you may do so without realizing that you’re not actually going anywhere.

The wheel has quite a bit of travel. On my set, it will rotate about three full turns. I believe this is necessary because all of FM, including the standard and Japanese bands, is in one section. Therefore, the wheel needs to be able to turn a lot in order to separate those stations. However, this means that panning over a shortwave band that covers at most 500 kHz of spectrum includes a great deal of panning over static. This works to scan quickly, but there are undoubtedly even faster ways to do so.

Conclusions

It’s a radio. It will pick up stations and make noise. In that, it works. However, this isn’t exactly a great set. The $22 price tag may forgive some of its flaws but not all of them.

Radios like the Tivdio models cost similar amounts and cover the spectrum more fully with some extra features. When I purchased this model, I expected the lack of features to be made up by convenient scanning over shortwave, relatively good sound, and relative disposability. I got enough for me to keep the set, but nothing more.

Pros:

  • Mediumwave is rather sensitive for those who enjoy listening to those signals.
  • Radio has a kickstand and the antenna can be rotated freely.
  • Radio supports headphones with inline microphone.

Cons:

  • FM is plagued by images of other stations that should not be there. This is rather bad.
  • FM is far too sensitive to antenna position.
  • Shortwave coverage, while it includes most of the spectrum in use, has big gaps that are actually being used by a lot of broadcasters.
  • Analog tuning works, but not really well. The knob can turn but does so with effort.

Would I recommend people to purchase this? Probably not.

Those who have higher-priced devices will get nothing from this. Those getting into the hobby aren’t going to get a ton of benefit from this, because tuning on shortwave requires enough familiarity with dial position that they may spend too long figuring it out. It would be useful on FM only if most other radios have been broken. It’s not even that good as an emergency set because of the FM sensitivity problem.

If all you want is analog tuning over the bands that are provided, the radio will do it for you. If you want more, buy something else.

Thanks for sharing your evaluation Laurence. Thanks for focusing on one of the points that is often overlooked with analog radios: the frequency coverage on various shortwave bands. The R-9012 does seem particularly segmented. 

Tecsun R-9012 retailers:

Post readers: Do you own the R-9012? What are your thoughts? Please comment!

Do you like the SWLing Post? Consider supporting us via Patreon or our Coffee Fund! Thank you!

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Jason gives a favorable review of the Sangean DT-120

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Sangean DT-120

In reply to Olivier’s post about the Sony SRF-M95, SWling Post contributor, Jason, notes:

Another amazing AM ultra light performer, the Sangean DT-120 or DT-180

I have the DT-120 in my pocket and it has got many hours of use. Travelling in outback Australia in April/May I was very impressed with it’s performance on AM.

Camped at the Devils Marbels 412km north of Alice Springs, I could receive it’s 783 kHz AM signal OK, weak obviously but definitely listenable. Of course the signal from Radio National at Tennant Creek on 684 AM was stronger, since it’s only 100km to the north of Devils Marbles.

Very happy with the little Sangean. It’s by far and away the pocket radio with the best DX reception I’ve ever owned, but the Tecsun R-209 and the Sangean SR-35 are probably the two best AM DX pocket radios with a speaker.

One day I will pick up a Sangean DT-250, but it’s probably not much better than the Sangean DT-210 I already have, which is another good choice with a speaker.

Thanks for sharing your comments, Jason! And, wow, I’d love to make that camping pilgrimage to the Devil’s Marbles–sounds remote and fantastic!

If you like ultralight radios like the Sangean DT-120, check out our endurance test of the Sangean DT-160CL and Sony SRF-39FP.

Links:

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Guest Post: A DSP Hi-Fi “Stupid Radio Trick”

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

Stupid Radio Trick – DSP “Hi-Fi”

by TomL

If you can remember the 1960’s, there was an audiophile rage going on called Hi-Fi.  The base unit consisted of a ponderous piece of furniture consisting of a rectangular cabinet and equally large mellow sounding speaker of fairly smooth frequency response, say in the range of around 40 – 15000 Hz.  They would have a built-in radio (using vacuum tubes) with large analog scale. Most would also have a “record player” embedded on the top to spin some vinyl discs (78 or 33 rpm).

For pedestrian consumers, it became a decision of how to keep up with the Joneses, so-to-speak.  And that meant a trip to Sears to look at the latest offerings. When the decision finally came to purchase, of course no one could buy it outright.  So, to add to the suspense, one had to put money down on “Lay-A-Way” plan that did not allow you to take possession of your prized choice until the last monthly payment!  One had to visit or mail in a check every month.

So where am I going with all this?  Well, as you can see from the photo [above], I have purchased three portable radios for three very different purposes.   All three were painstakingly studied and reviewed and weighed against all other possible choices. All are highly rated by the usual reviewers like RadioJayallen, SWLing Blog readers and other internet personalities.  The Sangean is for home use and listening to baseball games when I did not want to fire up the stereo hooked up to the Grundig Satellit 800. The small Sony ICF-19 is a phenomenal knock around radio for the car and listening while out to lunch or a walk in the park.  The large Tecsun S-8800 is a possible replacement for my ailing 20+ year old Sony ICF-2010 for shortwave use.

Well, I was tired of listening to any one of them in terms of sound quality.  The Sangean has too much upper bass/lower mid range, the small Sony is very carefully maximized for total speech clarity, and the Tecsun seems to lack a little in the mid range frequencies (compared to highs and lows).  Staring at them, I thought to self, “What if I turn on the Sangean and Sony together???” What ensued was a revelatory sonic experience (it sounded pretty good)! One seemed to fill in the other in certain ways. But it was not perfect.

Duh, I had the new Tecsun in a carry case while trying to decide if I send it back for a tuning quirk and dug it out and plopped it on top.  Turning it on, I heard more lows and highs, just like a Field Radio should have but with the mid range filled in! After very careful volume adjustment, I now have something that could rightly be called DSP Hi-Fi.  At least, that is what I am calling it for now. ?

Violin and piano pop-out of an orchestra but not too harsh sounding.  Rock & Roll sounds loud and punchy without that boombox effect. Bass lows are there (could be better, now all I need is a small subwoofer connected to the Tecsun line-out ???).  Highs are there too but well controlled. Mid range voice clarity is stunning, as if someone is in the room with me but not sounding too forward! It is not room-filling but acts more like a near-field monitor.  I like that I can line-up the speakers over each other.

The really fortunate thing is that all three radios have complete DSP for FM and receive my favorite over-the-horizon station with very similar reception quality.  Also, they process DSP with a similar delay before output to its respective speaker. The sound is fairly coherent and even though it is still mono output, the full range of musical fidelity can be appreciated better.  It is not audiophile quality but it is very satisfying and I can actually hear more details in the music than with any one of the radios by themselves. Just goes to show you that you CAN teach a new Radio dog old Tricks (LOL)!

Happy Listening,

TomL

I love it, Tom!  Thanks for pointing out that sometimes it takes a “stupid radio trick” to really produce some amazing audio fidelity! This reminds me that in the early 90s, I used to have a Zenith Transoceanic and RadioShack DX-440 on my radio table in my room.  If I recall correctly, the Zenith was on my left and the DX-440 on the right. I used to tune to shortwave, MW and FM stations and produce a makeshift “stereo” effect by playing both at the same time. Sometimes, on shortwave, it actually helped me discern voices in weak signal work!

Thanks again, Tom!

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Olivier is pleased with the Sony SRF-M95, shares internal photo

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Many thanks to SWLing Post contributor, Olivier Tkaczuk (F4BXV), who writes:

Hello, my name is Olivier TKACZUK 36 years F4BXV and I live in the north of France.

Just to present my last Sony SRF-M95 AM/MW bought on eBay for 13 euros.

[I regularly receive] Absolute Radio in England…and also Radio Nacional de España.

[H]ere is an internal photo:

Thank you for your website it gives me taste on the radio.73’s Olivier F4BXV

Many thanks, Olivier! I’ve always loved this über-compact AM/FM radios. They remind me of the small radios I used to sneak into school when I was a kid! Sounds like the SRF-M95 is a capable little receiver as well–thanks for sharing the photos.

Glad you’re enjoying the SWLing Post!

Click here to search eBay for the Sony SRF-M95.

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