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Radiosophy HD100 Is Economical

Although the Radiosophy HD100 table radio originally listed for $119.99, it was sold at a special introductory price of $99.95 and will remain at that price, according to the company.

(click thumbnail)Although the Radiosophy HD100 table radio originally listed for $119.99, it was sold at a special introductory price of $99.95 and will remain at that price, according to the company. The radio can only be purchased from Radiosophy.

Early buyers were able to get the HD100 for $59.99 after a $40 rebate from Ibiquity Digital Corp.

The carton contains the radio, power supply, AM loop antenna, FM antenna, user guide and “quick start” reference sheet.

The radio is in a glossy rounded black plastic case that reminds me of the Bakelite cases of vintage radios. It is approximately 12 inches wide, 6/1-2 inches high and 4 inches deep. The display and controls are in the center between two small speakers that are about 8 inches apart. There are 15 pushbuttons, a rotary volume control and a 3.5 mm stereo headphone jack that can also serve as a line output.

The rear of the radio has a standard F connector for the FM antenna input; the telescopic rod antenna threads into this connector. There are two quick-connect push terminals for the external AM antenna.

The AM loop antenna is supplied with tinned wire leads. There is a 3.5 mm “Aux Input” jack for MP3 players or other line-level audio sources. The “wall wart” external power supply provides 5 volts and 10.5 volts DC through a 6-foot cable that connects with a sturdy-looking four-pin connector on the rear.

The radio has no provision for battery power and doesn’t contain a battery for memory storage.

‘Seek All’

When the radio is powered up, the display shows the time as 12:00 AM. The quick reference sheet is helpful when setting the clock, user preferences and station presets.

The radio can be set to “Seek All” for any station, analog or digital. You can also set it to “Seek HD” and it will only stop on signals where a digital signal is present. There are five preset buttons that allow you to store five AM and five FM stations.

The radio has a sleep timer that will allow you to listen for 1 to 120 minutes before it turns off. The alarm can be set to wake you up with the radio or a series of beeps. Pushing the snooze button when the alarm trips will give you a little more silence before the alarm trips again. The instructions don’t specify the snooze time and I didn’t test it.

The blue backlit liquid crystal display has two lines of text. When receiving an analog signal, the upper line will show the station frequency. Although not mentioned in the instructions, the upper line also displays the text from analog FM stations with a 57 kHz RBDS subcarrier.

If the RBDS carrier is receivable, the frequency changes to the stations RBDS text. If the RBDS data is static, it will stay fixed. If a station is using dynamic RBDS, the display is a little slow to respond.

Two of our stations pulse out the eight-character PS catagory RBDS strings every 1.6 seconds. This is formatted for us by Google/dMarc and contains artist and song title text from our Scott Studios PC. The artist and title information is always followed by the station identifier strings. The LCD display takes about half a second to change, then displays the characters for about a second before the next change. This isn’t a problem when receiving stations that transmit a fixed eight-character PS string. If a station broadcasts in HD-R and also has an analog RBDS carrier, you can’t see the RBDS text on the HD100. The radio automatically changes to HD mode and defeats the RBDS display.

When receiving a digital station, the call letters are displayed on the upper line with “HD” before AM or FM. If an FM station is transmitting an HD2 stream, the display shows the call letters followed by a -1 or -2. When receiving an HD-R station with multiple programs, you just use the TUNE + and – buttons to select the HD1 or HD2 programs. At the time of testing, there were no HD3 streams available in the Detroit area but I assume the radio would step through those in the same way.

LED indicators

When receiving an HD signal, you can push the ENTER button to change the lower line on the display to five choices. It will step through frequency, time, artist, title and a signal-strength bar graph. The artist and title fields only work when stations are transmitting that information in the program-associated-data stream.

There are two LED indicators. A red one lights when an FM stereo signal is present. It stays lit when the radio locks on HD Radio. When tuned to an HD-R station, the blue “DIGITAL” LED flashes for about 5 seconds, then stays lit when it is locked.

On weaker signals, the light will begin flashing at times and the radio transitions back to analog receive mode. The radio doesn’t give you the option to select analog- or digital-only receive mode; it’s always automatic.

The FM performance is good with the supplied telescopic rod. The receiver will lock on HD-R signals that are solid in analog stereo. I connected an outdoor omnidirectional FM antenna with RG-6 coax and reception improved greatly, as would be expected.

The standard 75 ohm type F input for FM is a nice feature. When it transitions from analog FM to HD, the hiss and swishing in the noise floor go away and the signal-to-noise ratio improves dramatically. This is especially noticeable while listening with headphones.

The AM performance isn’t quite as good as FM. The radio doesn’t seem to have an internal ferrite AM antenna. You need to have an external AM antenna connected to the rear panel to receive anything.

The performance from the supplied loop antenna was disappointing. It only allows receiving strong local signals. Weaker analog stations sound noisier when compared to other small AM radios.

It seems to be more susceptible to interference from power lines and other sources of noise, like computers. The loop needs to be positioned perfectly to lock on AM HD stations, and the signal must be strong.

I connected my Terk “AM Advantage” tunable loop antenna and reception was much better. I was able to lock on two more AM stations in HD-R and analog stations had lower noise.

The transition from analog to digital is much more noticeable with AM. When it locks on HD-R, the noise floor drops greatly, the audio gets much brighter, and it’s in stereo. I was able to listen to music on two AM stations in HD-R, 870 kHz WKAR and 910 kHz WFDF. Both stations sounded very good and the audio truly is close to the quality of analog FM.

Ibiquity codec less ‘swishy’

The Ibiquity AM codec sounds amazingly good considering the bit rate is only 32 kilobits per second. Many Internet radio streams use this bit rate, but Ibiquity’s codec sounds better with less of the “swishy” high frequencies in the audio.

I used a 3.5 mm stereo cable to connect my Sansa MP3 player to the rear “Aux Input” and playback was fine. The audio level was about equal to the radio. The audio quality is what you would expect from a pair of small speakers.

It sounds good, but you won’t hear thundering bass or sizzling highs. It’s fine for average listening. A two-way speaker system with larger woofers and tweeters would be a nice improvement, but would have surely increased the cost and size of the radio. The radio doesn’t have any tone or EQ controls for the audio.

The volume control is rather unusual, you can turn it all the way up without audible clipping distortion from the speakers or headphone jack. Plugging in headphones will mute the speakers. The level from the headphone jack is high enough for all but the most inefficient headphones. With a pair of Sennheiser HD202 headphones, the level gets uncomfortably loud with the volume fully clockwise, but still without clipping distortion. The earliest HD100 radios sold had a lower headphone output level, according to the manufacturer.

Product CapsuleRadiosophy LLC
HD100 HD Radio Receiver

Thumbs Up

  • Low cost and small size
  • Very good FM sensitivity & selectivity
  • Standard type “F” FM antenna input
  • Handy auxiliary audio input jack
  • 3.5 mm stereo headphone jack can be used as “line output”

Thumbs Down

  • Disappointing AM reception with supplied loop antenna
  • Needs 120 VAC, won’t operate on batteries

$99.95, available only from Radiosophy

(877) 443-7234 | www.radiosophy.comI measured the peak-to-peak voltage from the headphone jack with an oscilloscope. It’s about 0.5 volt p-p maximum with a 10k ohm load. This is a standard –10 dBV consumer line level. The volume can be left at maximum if you’re using the headphone jack as a line-level output, I couldn’t see or hear clipping distortion.

When listening to an analog AM or FM station, the audio is still delayed a small fraction of a second. This is only noticeable if you have another analog radio playing the same station near the HD100. I suspect the delay may be caused by the receiver digitizing the analog signal.

The transitions from analog to digital and vice versa were mostly perfect. HD Radio stations are doing a much better job setting the analog delay now.

I drove from Lansing to the suburbs north of Detroit to try the radio in a market with many more HD-R signals to sample. It was interesting seeing how much variation there is in implementing IBOC. Some FM stations sounded noticeably brighter and better in HD-R. Other FM stations sounded almost identical when comparing their analog audio to HD-R. I suspect they are using the same audio processor for analog and digital.

Who is IDing their HD-R?

The AM stations sound dramatically brighter in digital, but most carry talk programming so the stereo separation isn’t very useful.

The way stations use PAD text varied widely: 95.5 kHz WKQI, 98.7 kHz WVMV, 99.5 kHz WYCD and 104.3 kHz WOMC were impressive with their artist and title fields working on both the HD1 and HD2 streams.

WNIC 100.3 kHz had its artist and title PAD working, but didn’t have HD2 programming. WDRQ 93.1 kHz had artist and title on HD1, with blank fields on the HD2 stream that airs WJR’s audio. WMXD 92.3 kHz, WJLB 97.9 kHz and WDMK 105.9 kHz didn’t have artist and title info working or HD2 programming.

WCSX 94.7 kHz only had “94.7 WCSX” and “The Classic Rock Station” in the artist and title fields. The artist and title text would be a nice addition on the WCSX “Deep Cuts” HD2 stream, but the unused fields came up blank on the HD100.

WRIF 101.1 kHz had the artist and title fields frozen on “Creed — My Sacrifice Album Version” and the HD2 stream only displayed “RIFF2 — Made in Detroit.” WMGC 105.1 kHz had the artist and title fields frozen on “Irene Cara — What a Feeling” and the HD2 stream only displayed “More Magic — WMGC Magic 105.1.” The station obviously was experiencing some kind of digital glitch with the stuck text fields.

The HD100 would be a good receiver for someone who wants to check out HD Radio for around $100. You can patch it into an audio system with bigger speakers set farther apart if you want to impress people.

Plan on finding a better AM antenna if you are serious about AM HD-R reception. The manual could use a rewrite, but the technically savvy types will figure out how the buttons need to be pushed.