Sony has released an inexpensive ($99.95) add-in high-fidelity component tuner, bringing HD Radio performance to the audiophile crowd. It takes advantage of an RF DSP engine to provide remarkable analog FM signal processing along with HD Radio.
The XDR-F1HD shines on FM with superb selectivity and extended sensitivity and signal-to-noise ratio, especially in stereo. Using DSP noise reduction, the Sony appears to offer about a 20 dB improvement in stereo over conventional consumer receivers.
This means the old 20 dB penalty of multiplex FM stereo has finally been erased. There is no longer any reason to blend to monaural to reduce the noise. It is amazing to be able to lock to a distant FM station, hear its audio with little or no noise and maintain excellent stereo separation. The unit might make a good, inexpensive, front end for a translator.
In my opinion, the analog FM mode of the XDR-F1HD is outstanding.
What you get is a diminutive tuner, smaller than normal component tuners such as the Onkyo Integra T-9090, which has been my benchmark radio for many years. At only 7 inches across by 2-1/4 inches high by 6-1/4 inches deep it can easily be lost in a pile of brochures.
It has a calm 2-3/4 inch wide LCD display, black letters on light blue backlight, with three user-adjustable brightness levels. The display is always lit. The dimmest setting can be used as soft night light.
The two-pronged power cord is captive. The other connections on the rear panel are a pair of RCA pin jacks for audio out, an F female panel jack for antenna and a pair of press-release wire posts for the external balanced AM loop antenna.
It is truly balanced to help reduce stray noise pickup from the receiver. If you connect an unbalanced AM antenna the locally induced noise will go up dramatically.
Sony also packed a wire dipole antenna, identical to the one that came with my Boston Acoustics Recepter HD. I'm guessing it's a generic wire antenna manufactured in China and used by most manufacturers whose products are being made there. This type of antenna is only useful for strong city-grade signals. At my house, that limited the number of full quieting signals to less than six.
The infrared remote duplicates all the controls on the radio itself with the addition of direct buttons for display brightness, sleep mode and numeric keypad for direct selection of presets. Unfortunately there is no way to directly select frequencies. You only get up/down buttons to navigate across an entire band either AM or FM.
Thus, you have to make use of the 20 AM and 20 FM preset memories to provide instant numerical access; this is available via the remote. Preset memories will store multicast channels. The pushbuttons are on top of the tuner as there is insufficient real estate on the front panel.
Rear View It is a bit awkward to go from the presets to manual dial mode. If you press Tune/Select plus or minus when in preset mode, the unit will dump you into non-preset register one channel higher or lower than your last preset memory, based upon which button you pressed.
If you press the Band button it will switch to the opposite band. Press Band again and it will return you to the same band and same frequency you had in preset mode.
There are two Scan functions, normal analog and HD Radio only. Each will sample the entire band, stopping on strong enough signals for a few seconds before moving on.
HD Radio Scan attempts to look for and lock to HD Radio carriers before moving on. The unit will mute all audio until it locks to a digital signal. It can be a slow process.
The display does not indicate Stereo mode as it is always ready to decode any L/R audio information it can detect. If you want to force reception to monaural you'll have to mix L+R audio together outside the radio.
The display does decode RDS or PAD data, a nice touch since few HD Radios do both. The display button toggles through three modes, one line of RDS/Pad data plus frequency, one line of RDS/Pad data plus time of day or up to three lines of scrolled RDS/PAD data.
In spite of some of the awkwardness of the controls, the radio responds quickly and reliably without exhibiting any of the glitches and freeze-ups we've come to expect from many of the HD Radio receivers already on the market.
The XDR-F1HD is a tuner, not a receiver and doesn't have speakers or a headphone jack.
Another annoyance is the inability to choose only North American FM channel spacing. The Sony tunes to both odd and even frequencies.
I operate a Class B FM station, the tower of which is shadowed from my home by a large hill to my east. This station is also short-spaced from two other Class Bs to the north and south.
Sony XDR-F1HD Tuner Thumbs Up
- Very responsive; few bugs
- Superb FM selectivity and extended sensitivity and S/N ratio
- Can be programmed to remember the last multicast stream
- Audiophile-quality sound
- Good AM IBOC reception
- No direct frequency input capability for tuning
- Loses settings and preset memories upon power loss
- No restart upon power loss and restoration
- It cannot be programmed to receive only odd frequencies
- It cannot do split mode or any other engineering mode
Go to the MP3 and Portable Electronics tab, and click on Radios and Boomboxes. Here is where it gets interesting. With my 10-element rooftop antenna aimed north, the Sony tuner fully captures the northern station, which is at least 90 miles away. I can hear a little bit of distortion on their FM stereo signal due to co-channel noise, but it is listenable without a trace of my station's FM audio. However, within a few seconds the Sony will lock to the HD Radio carriers of my station.
Suddenly I'm hearing my signal in clean HD Radio. This is because the short-spaced stations to my north and south are not yet transmitting HD Radio carriers!
There is a Class A classical music FM station approximately 75 miles to my north. It is a joy to listen to as its stereo signal is noise free much of the time, has good separation and no hiss or static from that distance, with an ERP of only 400 watts. None of my other receivers, including the Onkyo, can do this trick while maintaining full stereo.
There are two Class A stations on the air at 99.3 approximately 90 miles apart, one to my north and the other to my south. With an estimated best-case antenna front-to-back ratio of 20 dB, the Sony can reproduce either station with full quieting depending upon antenna orientation.
For serious FM DX testing I tuned to WALK(FM), in Patchogue Long Island on 97.5 MHz. The distance is 158 miles. In the summer, the daytime signal is about 50 percent of the time. At night and in winter it's more like 80 percent availability. It is full quieting in monaural at least 40 percent of the time. This path is probably mostly over water including the Connecticut River. With the Sony, it is equally quiet in stereo.
For yet another serious DX test I aimed my antenna north towards Montreal, Canada. CKMF(FM) runs 75 kW and is 173 miles to my north. The Sony reproduces its FM stereo signal well. My BA Recepter can also pick up this station, but not in stereo and with a bit more noise.
IBOC sensitivity seems to be almost identical between various models when given the same quality outdoor antenna. My BA Recepter, while exhibiting worse FM performance than the Sony, is pretty much identical in HD Radio.
Some have given the BA Receptor a bum rap regarding sensitivity. It does generate a lot of self noise, but given a good external antenna I've had excellent results comparable to other quality FM receivers.
It is possible to use the Sony for FM HD Radio multicast monitoring. The unit will stay tuned to an HD2 or HD3 stream if you save it as a preset. But it has a quirk. The display will not give you an HD2 indication if you tune away and tune back after loss of RF.
But it will play back the HD2 stream called for by that preset memory. The other caveat is loss of AC power. The radio will reset to off, upon even the briefest power blink.
Also, nonvolatile memory retention is short. One of the modifications circulating on the Web (see Brian Beezley's Web site, www.hamradio.com/k6sti/xdr-f1hd.htm), is to upgrade the memory capacitor to a larger value. If you replace it with at least a 1.5 farad super capacitor I believe that you can increase retention to more than a day.
A UPS with sufficient run time might be a prerequisite unless you can figure out how to force the Sony to power back up after an outage. A reed relay and the appropriate logic could be added to pulse the radio's On/Off switch circuit upon restoration of AC power.
FM and HD Radio audio quality is very good and can be improved to near-perfectly flat audiophile quality with the addition of better audio low-pass filtering. This modification is also posted on Beezley's site.
What about AM?
Analog AM reception is good but the audio fidelity is lacking as it doesn't attempt to provide the available 10 kHz audio bandwidth. Instead it opts for the more common 5 kHz or lower brick-wall limit. Testing AM capability has been a challenge for me as I am not within significant groundwave of any AM station, either analog or IBOC.
My AM HD Radio station is about 5 miles too far away and behind a hill, to boot. Also, while the Sony's balanced AM input and its loop antenna are quite effective in reducing local noise, the unit is insufficient to receive weak AM signals. You really need a larger loop or long-wire antenna located away from living areas that these days are filled with RF noise generators.
I have a modest amateur radio vertical antenna hidden amongst the trees away from my house. It works well as an AM broadcast band receive antenna. The problem is matching the low-impedance balanced input of the Sony to a 50 ohm coaxial line.
I found that eight turns of telephone interconnect wire wrapped around the Sony-provided AM loop antenna made a sufficient match. In fact, I could decode the PAD data from Radio Disney WQEW(AM) on 1560 kHz in New York City. Unfortunately, the signal was not strong enough to permit recovery of the audio stream.
In the daytime, my 1220 kHz AM IBOC station operates at 1,000 watts. Using my amateur radio vertical antenna I was able to achieve digital lock with the Sony. I've not been able to do so with the BA Recepter even with its loop antenna coupled to my vertical.
Sony appears to be somewhat more sensitive for AM IBOC reception. In analog mode I can hear noise but it will still lock to digital. The fidelity difference is dramatic. The blending back and forth is smooth and not jarring.
On AM, the BA Recepter soft mutes earlier than the Sony. When listening to both radios simultaneously it's obvious that Sony's DSP engine is running faster as it exhibits less audio delay.
We tend to forget a lesson from the early days of AM radio and television. A good antenna is key to good reception regardless whether the receiver is deaf or state-of-the-art.
With the proliferation of cellular handsets with hidden internal antennas and wireless networks used by laptop computers without visible aerials, folks have come to expect radio gear to function miraculously without them. This just isn't so.
Cell phones work because of the very short wavelengths at cellular frequencies and short distances to multiple cell sites. Even in an urban area with many city-grade signals, a good external or outdoor antenna will provide significant improvement.
To summarize, if you need engineering functions you'll have to look elsewhere and spend more money. But if you are looking for one of the best-performing analog FM tuners in commercial production, an inexpensive HD Radio that can be used to reliably monitor multicast channels, a high-quality IBOC tuner to add to your high-end sound system, the XDR-F1HD is it.
The author is chief engineer of Saga Communications in Keene, N.H., and owner of Wilner Associates in Putney, Vt.