Tag Archives: FM

Sangean DT-800 Review: AM/FM/Weather ultra-compact radio

Two months ago, SWLing Post reader Paul Adler wrote to ask:

“Any reviews and comparisons of the Sangean DT-800?”

The Sangean DT-800? This caught my attention, as I wasn’t, at the time, familiar with this recent addition to the Sangean product family.  So I promptly began investigating the new product, and checked out the manual; I found it has a few features that really intrigue me, namely:

  • The ability to turn off soft muting
  • The ability to internally recharge NiMH AA batteries
  • Multiple bandwidth on AM and FM
  • Weather band with weather alerts
  • FM RDS
  • No telescoping antenna––rather, an included wire antenna

In my mind, these features seemed to set it apart from other similar portables.  And with the ability to defeat the soft mute, I wondered if it could make for a formidable Ultralight DX radio?

I contacted Sangean, and they kindly sent me a review sample of the DT-800. It comes in two chassis colors: standard black and and a bright fire yellow. I chose yellow, which makes it easier to spot should this handheld be lost or dropped in an outdoor setting.

Thanks for the suggestion, Paul!

Giveaway!  By the way: since this is a product sample and was sent to me free of charge, I’m going to give it away to a lucky SWLing Post Coffee Fund or Patreon supporter next week, just to say thanks!

Now, let’s get on with the review…

Initial impressions

As with almost all Sangean products, the DT-800 arrives as a complete package, with all accessories. Inside, you’ll find the radio, a full-length multi-language owner’s manual, a warranty card, an AC adapter (with in-line RF chokes, nice touch), in-ear headphones, an external wire antenna, and a belt clip.

The DT-800 fits nicely in the hand, and the matte finish on the sides and bottom of the radio make gripping it quite easy, lessening the chance of dropping or losing the unit.

The front panel is simple: five multi-function preset buttons and a Page/Menu button. All of the buttons are tactile and have a matte finish, as well; they feel of good quality and have a great response.

The right side of the radio (see side view, above) has a tuning/select up/down jog switch, a mechanical keylock button and a MicroUSB DC in port.

On the left side of the radio (see left side view, above) you’ll find the volume up/down buttons and a stereo/mono/speaker mechanical switch which you can use to switch between the internal speaker and headphones.

On top of the radio (above) you’ll find the power button, band selection button and the headphones port, which doubles as the external antenna port.

On the back of the radio you’ll find the DBB bass-boost slider switch, the battery compartment, and a belt clip.

One thing you’ll quickly notice is a lack of any telescoping whip antenna. Instead, the DT-800 ships with a wire antenna that’s almost three feet long. I suspect that this is the same type of FM antenna that shipped with the Sangean WR-7 (click here to read review).

Design/Ergonomics

All in all, I’m very pleased with the DT-800’s design: it fits well in the hand, the buttons and controls are easy to use, and it’s small enough––and flat enough––to easily slip in a pocket, go-bag, or carry-on. A great portable for one-hand operation. It’s also lightweight, even with the batteries inserted. Truly, this appears to be a quality little radio.

Tuning the DT-800 is a simple process: simply utilize the up/down rocker switch on the right side of the radio to increase by specified frequency steps (selectable 50/100 kHz FM or 1/9/10 kHz AM), or push and hold it in one direction to skip across the band. While the DT-800 does mute between frequencies, it’s not annoying––in fact, muting is brief and audio recovery is rapid so you can actually carry out meaningful band-scanning, actually hearing stations between the steps. If you press the rocker switch, it will initiate an auto-scan in the direction you’re tuning.

While the DT-800 lacks a keypad for frequency input (in truth, I would not expect such a thing on a walkman-style receiver)  it does make tuning to your favorite stations quite easy with 20 FM, 20 AM, and 5 WX presets. Saving a station to memory is truly a breeze: simply select the page you’d like to save it to, then press and hold the preset button to save it to one of the numbered presets. Really, it couldn’t be easier.

To change the volume on this radio, you use rocker buttons on the left side of the radio to increase or decrease volume up to 25 levels. I particularly like the fact that level 1 is very quiet and 25 is as loud as you would ever want from a small radio. I mention this because, in the past, I have reviewed radios that had coarse volume steps, and the lowest setting is louder than I prefer: not so with this little rig.

Entering menu items on the DT-800 is quite easy, too.  Some are accessed by pressing and holding the Page/Menu button and then cycling through and selecting items with the tuning up/down switch. Others are accessed by pressing and holding the Page/Menu button, then selecting one of the five buttons on the front panel (note that each menu function is listed below the numbered button).

The DT-800’s display is backlit and large, thus very easy to read at any viewing angle.

AC Adapter

I can’t think of the last time I gave an included AC adapter its own subheading in a review, but the DT-800 power supply deserves one.

Not only does the DT-800 ship with a power supply (AC adapter), but it’s a quality one: the cord jacketing is thick and feels exceptionally durable––and though I’m not going to cut it apart to find out, I expect the wiring within it is a heavier gauge, as well. This adapter also has no less than two in-line RF chokes.

In a day and age when included “wall wart” power supplies are often of the cheapest quality and spew so much radio interference that they render attached receivers useless, the DT-800 adapter is a very welcome addition to this radio’s kit.

Well played, Sangean! I hope other radio manufacturers follow your lead.

Batteries

Lately, it seems most new radios are being designed to accommodate slim Lithium Ion battery packs. So, another welcome sight was opening the DT-800’s battery compartment to find slots for two AA batteries.

While Li-ion batteries have advantages in terms of weight and size, I prefer AA batteries for pocket and travel radios, as AA batteries are so ubiquitous on this planet and are available in all but the most remote regions of the world.

And better yet? You can internally recharge NiMH batteries with the DT-800. The DT-800 ships with a default setting for alkaline batteries. But to internally recharge NiMH batteries, simply open the battery compartment and change the battery type switch from “Alkaline” to “NiMH.”

This is an amazing and useful feature, but just be sure if you ever use the NiMH internal recharging function and then switch to alkaline cells, that you change the battery selection switch back to the alkaline setting. You certainly wouldn’t want the DT-800 to attempt recharging your alkaline cells!

As you can see in this photo, I’ve been using Panasonic Eneloop NiMH batteries in the DT-800. I use a special charger for Eneloops, so have kept the battery selection switch set to alkaline so the DT-800 doesn’t attempt to charge them. I might even put a small piece of colored tape on the switch to keep it in place for now.

Audio

The audio via headphones? It sounds great on the DT-800!

Indeed, the DT-800’s included in-ear style stereo earphones are a cut above most other included-with-a-product earphones, and as a result, produce more pleasant audio.

With the headphones engaged, FM offers selectable mono or stereo; mono, of course, makes marginal stations more stable since the stereo lock isn’t struggling.

Like the Walkman radios of days gone by, the DT-800 uses the headphone cord as an antenna when it’s attached. If you’re using the internal speaker, you’ll need to attach the included external wire antenna for FM and WX bands.

The DT-800 internal speaker produces decent audio for the size of the radio. The speaker is tiny, so the audio is somewhat tinny (narrow in range) when listening to music. But the DT-800 also has a DBB (Dynamic Bass Boost) switch––engaging this will increase the bass response a bit, most noticeable when using headphones.

Performance

The DT-800 has three bands: FM, AM (mediumwave), and WX (weather). Let’s take a look at each.

FM Band

The DT-800 sports a unique feature on the FM band: the ability to select between a wide or a narrow filter. Since the dawn of the DSP chip, many a portable radio has enjoyed selectable bandwidth filters, but it’s a rare portable that has FM filters. I do pretty much all of my FM listening with the wide filter engaged, but if you live in an urban area with a crowded FM band, choosing the narrow filter, even if it compromises audio fidelity a bit, will give you better selectivity. Nice touch, Sangean!

In terms of sensitivity, with the external antenna inserted, I’ve been very pleased with the DT-800. It receives all of my benchmark FM stations. With headphones inserted (used as an antenna) and stereo engaged, it has ever-so-slightly less sensitivity than several of my other DSP portables. With the headphones inserted and FM in mono, I find that it’s on par with––or surpasses––my other reference DSP portables.

Here’s a little wrinkle, though: when listening with the internal speaker, you must insert the external wire antenna to use this receiver on FM. Without the external antenna, sensitivity decreases by a good 70-80%, as you essentially have no antenna. If you live in an area with strong FM stations, you’ve nothing to fear, but if you live in a rural area, you’ll certainly want to keep that wire antenna handy.

On one hand, the wire antenna is easier and more flexible to deploy than attached telescopic antennas, which can be bent or broken. But on the other, an external wire antenna is just another item you’ll need to pack and take along with the radio if you plan to listen via the internal speaker.

If you plan to listen with headphones, however, no worries! I find the sensitivity with headphones inserted to be just as effective. In fact, instead of taking along the wire antenna you could bring the included headphones, and they’ll double as an external antenna while listening via the internal speaker. In my tests, the headphones performed about as well as the external wire antenna.

My advice? If you purchase the DT-800, either keep the small wire antenna or a pair of headphones nearby to insure you’re getting the best FM reception.

Weather Band

The same notes above about the necessity of an external wire antenna apply on the weather band as well as the FM band.

With the wire antenna or a set of headphones connected, weather radio reception is good. I was able to receive both of my local NOAA weather reference frequencies.

To be clear, the DT-800 is not as sensitive as my C. Crane CC Skywave or CC Skywave SSB––which are truly WX band benchmarks––but it will likely receive your local NOAA or Environment Canada broadcasts as well as most other weather radios.

The DT-800 also includes a Weather Alert feature, but as Sangean notes, you should only use this feature while the radio is plugged into mains power, as it will drain batteries about as effectively as if you were listening to an FM radio station.

AM/Mediumwave Band

If there’s a weak point on the DT-800, I would say it’s the AM band.

Don’t get me wrong: at first blush, the DT-800 looks like a little Ultralight DXing dream, as it’s loaded with great features, such as:

  • multiple bandwidths (wide/narrow),
  • 9/10 kHz spacing,
  • well-balanced AGC (auto gain control),
  • as well as the ability to turn off soft muting.

Yes, the DT-800 has the ability to disable soft mute. Thank you, Sangean! So far, Sangean seems to be one of the only radio manufacturers that enables this DSP chip option in their product line. Another receiver with the ability to disable soft mute was the Sangean ATS-405 (check out our ATS-405 review). I wish other radio manufacturers would do the same because soft mute is what often makes listening to weak mediumwave signals so fatiguing. With soft mute disengaged, weak signals enjoy better audio stability as they’re not fighting to stay above the muting threshold.

But, I’m sorry, DXers: unfortunately, the DT-800’s weakness on AM is the same as the ATS-405 on AM (and shortwave): a higher-than-average noise floor. Somehow, internal noise is being generated and not being contained by shielding and grounding.

I made a short comparison video to demonstrate the noises heard via the DT-800. Before you ask: yes, these noises are present regardless of radio location, or whether or not there are other radios nearby. In addition, I made this video on a folding table far away from my house or any other potential sources of noise (with the exception of my iPhone which was used to make the video). This is the same low-noise spot I use to do comparison tests of all my portable receivers:

Click here to view this video on YouTube.

As I note in the video, the noise floor isn’t consistent across the band––some parts are lower, other parts higher. One of the noise peaks is around 1600 kHz which, unfortunately for me, is where my favorite local AM station resides.

So is this a deal-breaker?  No…not necessarily.  For the casual AM radio listener––a listener primarily focused on listening to local AM stations––I think the DT-800 will please. In fact, I might not have noticed the elevated noise floor had I not: 1) listened to weaker AM stations, and 2) compared the DT-800 with other radios.

Since I’ve been using and listening to this radio for the better part of a month, I can state with confidence that most of my other portables outperform the DT-800 on mediumwave. I compared it with these rigs:

  • Sony ICF-S10MK2
  • Tecsun PL-310ET
  • CC Skywave
  • CC Skywave SSB
  • Radiwow R-108

To be clear, I believe the DT-800 has average MW sensitivity for a radio this size, but the noise floor sort of spoils any hopes of doing marginal or weak signal work, thus also making that awesome soft mute toggle less effective.

If you pair the DT-800 with a loop antenna like the AN200, which I highly recommend doing, it will help those weak signals rise above the noise. Otherwise, if your primary goal in purchasing the DT-800 is to listen to mediumwave, I regret to say, you might want to take a pass on this one.

Summary

Every radio has its pros and cons. Each time I begin a review of a radio, I take notes from the very beginning so that I don’t forget my initial impressions and observations. Here’s the DT-800’s list, from the first moments I turned it on, to the time of writing this review:

Pros:

  • Great overall performance on FM
  • Quality construction and thoughtful ergonomics
  • Both clock and alarm for the traveler
  • Ability to switch between FM stereo/mono with headphones in use
  • Wide/narrow AM and FM filters
  • NiMH AA batteries can be recharged internally [make sure switch inside battery compartment is set to “NiMH”]
  • FM RDS (one mode)
  • Mechanical keylock switch
  • Ability to disable soft mute (other radio manufacturers take note!)
  • Small internal speaker providing quite decent audio
  • Comprehensive gear package includes radio, manuals, quality earphones, quality AC adapter, wire antenna
  • DC port is standard MicroUSB
  • Belt clip
  • Built-in speaker
  • Dynamic Bass Boost

Cons:

  • While listening via the DT-800’s internal speaker without antenna wire or headphones inserted: FM performance is lacking, while weather radio performance is very much lacking
  • AM band: Noise floor is higher than on comparable radios

Conclusion

The Sangean DT-800 is a solid little radio: it’s simple to operate and feels like a quality piece of kit. It’s perfect for hiking, or any sport or task where you’d like one-hand operation.

The DT-800 also has a surprising amount of features and customization through the menu settings––much more than one would expect––which puts it firmly into what I would call the “enthusiast-grade” radio category.

It’s for this reason that it’s a bit disappointing AM reception on this Sangean isn’t better.

The DT-800 has a lot of icing on the cake, otherwise: FM RDS, the ability to internally recharge AA batteries, built-in speaker, Dynamic Bass Boost, multiple bandwidths on AM and FM, the ability to disable soft mute–all of these are essentially pro features.

So, if you’re looking for a quality portable radio primarily for FM and WX band listening and perhaps catching the odd local AM broadcast, the DT-800 is a great choice.

Sangean DT-800 retailers:

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The Knitted Radio: An FM radio transmitter sweater

Many thanks to SWLing Post contributor, Paul, who shares a link to this fascinating maker/art piece from designer Irene Posch:

The Knitted Radio is an installation piece that manifests how to knit a sweater that is also a FM radio transmitter. The tactile centerpiece is a functional electronic object knitted out of ordinary wool and commonly available conductive materials. The accompanying knitting instructions, to be published in a knitting magazine, allows the reproduction of the electronic object by an alternative maker group.

The piece is part of a larger investigation into using traditional textile crafting techniques to create electronic components and devices from scratch. The critical question is whether ‘what’ one makes is really more important than ‘how’ one makes things. Industrial technology research is mostly driven by the desire to invent the next killer application, whereas artistic research holds the chance to question implications. By exploring alternative production procedures, we might be able to reveal skills, techniques and materials that have been uncharted, undervalued, or decisively left out of popular demand.[…]

Click here to continue reading and to check out other works by Irene Posch.

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Video: Excellent aircraft scatter demonstration

Many thanks to SWLing Post contributor, Robert Gulley, who shares this fascinating video from the Alps DX YouTube channel. In this short demonstartion, you can follow the flight path of an Airbus A320 and the signal from France Musique from Marseille as it is bounces off of the aircraft. Fascinating:

Click here to view on YouTube.

Description from YouTube: France Musique from Marseille / Grande Etoile on 94.2 received via Airscatter. I’m always amazed when I see and hear those signals coming out of nowhere when the plane crosses the path … Nothing a few seconds before, nothing right after. Radio is magic !

Equipment : ELAD S2 SDR + SDR# v1357, Airscout v1.1, 5 element Yagi (polar H).

I find this amazing. I’ll be the first to admit that I’ve never attempted FM aircraft scatter. Since I have an ADS-B receiver, and several excellent FM receivers, all I really need is a decent Yagi antenna and some careful planning.

Post Readers: Please comment if you’ve logged stations from aircraft scatter! Any tips?

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Are we entering the age of atomic radio?

(Source: arstechnica via Scott Schad)

A new antenna using single atoms could usher in the age of atomic radio

The team tested their device by recording themselves singing “Mary Had a Little Lamb”

JENNIFER OUELLETTE

In the 1950s, atomic clocks revolutionized precision time-keeping. Now we may be on the verge of so-called “atomic radio,” thanks to the development of a new type of antenna capable of receiving signals across a much wider range of frequencies (more than four octaves) that is highly resistant to electromagnetic interference.

An antenna is typically a collection of metal rods that pick up passing radio waves and convert their energy into an electrical current, which is then amplified. One might argue that the good old-fashioned radio antenna has served us well since the dawn of the 20th century, so why do we need anything to replace it?

According to David Anderson of Rydberg Technologies, those antennae are wavelength-dependent, so their size depends on whatever wavelength of signal they are trying to measure (they need to be about half the size of whatever wavelength they are designed to receive). That means you need antennae of several different sizes to measure different radio frequencies.

Anderson is a co-author of a new paper posted to the arXiv describing a novel alternative to conventional antennae, based on vapor cells filled with a gas of so-called “Rydberg atoms.” That just means the atoms are in an especially excited state, well above their ground (lowest-energy) state. This makes them especially sensitive to passing electric fields, like the alternating fields of radio waves. All you need is a means of detecting those interactions to turn them into quantum sensors.[…]

Read the full article at arstechnica.

Click here to download the research paper: An atomic receiver for AM and FM radio communication (PDF).

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Aeronautical RDS: Ivan’s impressive collection of in-flight FM stations

Many thanks to SWLing Post contributor, Ivan Cholakov (NO2CW), who writes:

Last week I took an Eton Satellit with me on a flight from Tampa, Florida to Washington DC. The radio is very light, portable and packed with features. I have used an SDR radio before for inlight FM reception where I recorded audio, but this time I decided to only count stations with an RDS lock. With so many signals battling RDS is tricky to catch as every 10 seconds or so one station comes on top of another. The flight was just short of 2 hours and I divided my logs into three 30 minute segments. Not suprisingly looking into the technicalities I noticed RDS is commonly received from stations 50 -100 kW of power and tall towers.

Interestingly signals seem to be stronger a lower altitudes. My theory is that FM broadcast antennas heavily favor gain on the horizontal plane parallel to the terrain and send as little signal as possible out into space. I overlaid my logs onto three maps and also a video:

Click here to view on YouTube.

Impressive Ivan! I’m taking a flight later this month and might even try this with the FM radio built into my Moto G6 smart phone which also includes RDS (although I doubt reception can match that of the Satellit.

This is fascinating, Ivan! Thank you for sharing.

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