Decoding the ATS-909X2: A Prosumer's Guide to its Hybrid (PLL/DSP) Tuner

In the world of portable multi-band radios, few names command as much respect—or scrutiny—as Sangean. When the SANGEAN ATS-909X2 was released, it wasn’t just another radio; it was the long-awaited successor to a legend. With a $300 price tag and a 4.1-star “mixed” rating from 500 critical hobbyists, it’s clear this is not a casual device.

This is not a review, but a “prosumer” analysis of the 909X2’s engineering philosophy. The original article, while well-intentioned, explains “what is AM/FM.” The $300 buyer doesn’t care what AM is; they care how well this device solves AM’s problems.

The 909X2 is a tool for the serious hobbyist—the ham radio operator, the Shortwave Listener (SWL), and the DXer. Its value is not in its features list alone, but in how it implements them, particularly its “hybrid” approach to tuning and its mastery of analog-world signals.

The “Hybrid” Tuner: A Deliberate Engineering Choice

The 909X2’s spec sheet reveals a critical design choice: it uses two different types of tuners.
1. DSP Tuner (for FM): The FM band (87.5-108MHz) is a high-fidelity, high-signal-strength band. Here, a Digital Signal Processing (DSP) chip is the perfect tool. It provides razor-sharp “brick-wall” filtering, which is why the 909X2 has excellent selectivity (rejecting a strong station next to a weak one) and can decode RDS (Radio Data System) information (like station names and song titles).
2. PLL Synthesized (for SW/MW/LW/AIR): For the weaker, more volatile AM-based bands (Shortwave, Mediumwave, Longwave, and Air), Sangean avoided a “do-it-all” DSP chip. Instead, it uses a high-end PLL (Phase-Locked Loop) synthesized tuner combined with Dual Conversions.

This is not “old” technology; it’s purposeful technology. A common complaint against all-in-one DSP radios is that the high-frequency digital processor itself creates internal digital noise, which can blind the receiver to the faint, distant signals a hobbyist is trying to catch.

By using a “cleaner” analog-style PLL circuit for its sensitive bands, Sangean prioritized sensitivity and a low noise floor over the digital convenience of a single DSP chip.

The SSB / ECSS Advantage: Why “Manual” Beats “Auto”

The 909X2’s true genius, as confirmed by expert user reviews, is in its handling of SSB (Single Sideband). This is the mode used by ham radio operators and utility stations.

A “prosumer” purchasing dilemma is often “Sangean 909X2 vs. Tecsun PL-990.” A key review from “Tom,” a ham radio operator, decodes this perfectly. The Tecsun (a DSP-based radio) has an automatic Synchronous Detector (“Synch”) to help clarify fading AM stations. The 909X2 does not.

Instead, the 909X2 provides an exceptionally “cleaner and smoother” SSB circuit with 10/20Hz fine-tuning. This allows the user to perform manual ECSS (Exalted Carrier Selectable Sideband)—a technique where you tune to a standard AM station using the LSB or USB mode and fine-tune it.

• The Result: The 909X2’s manual ECSS method sounds “very good” and “clearly beats the Tecsun.” The Tecsun’s automatic synch detector, by contrast, is “slow to lock,” “muffled, and slightly distorted.”
• The “Why”: Sangean’s analog-style PLL circuit provides a clean, stable signal that allows this advanced technique to work. The all-in-one DSP chip in the competitor “clips” and “muffles” the same signal.

This single, high-level feature—a superior SSB circuit—is what defines the 909X2 for its target audience.

Honest Engineering: The Pro-Grade Trade-Offs

The 909X2 is a $300 tool, and its 4.1-star rating reflects its “pro-level” trade-offs.

1. The “SSB Bandwidth” Flaw:
The most common complaint from experts (“Fletch”) is the “lack of filter selection on SSB.” While the radio offers 5 bandwidths for AM, it forces a single, fixed bandwidth for SSB. This is a baffling omission for a radio at this price. However, as “Fletch” and “Tom” both concede, the one filter Sangean chose “works well” and “sounds very good.” It’s a “flaw” that, in practice, is a well-chosen compromise.

2. The “SSB Volume” Quirk:
The second complaint (“Fletch”) is “low audio on SSB” with weak signals. This suggests the radio’s Automatic Gain Control (AGC) is tuned to favor stronger signals, requiring the user to manually adjust the Squelch and RF Gain to “dig” weak signals out of the noise. This is, again, a “pro” feature—it’s less “auto-magic” and requires more skill from the operator.

3. The “Tank” Build:
Where the 909X2 is universally praised is its physical engineering. Reviewers call it “beautifully constructed,” “a quality item,” and, most tellingly, “not cheap plastic like the Chinese brands.” The antenna is “much better quality” and “sturdy,” unlike the “flimsy” ones on competitors. This is a radio built to last, reflecting its 1974 Sangean heritage.

Coda: A Tool for the Patient Hobbyist

The SANGEAN ATS-909X2 is not a “plug-and-play” radio for a casual listener. It is a complex, feature-rich instrument for a hobbyist.

Its “mixed” 4.1-star rating is a perfect reflection of this. The 1-star reviews are often from users expecting a simple, loud radio. The 5-star reviews are from “ham radio operators” and experienced listeners who understand why its hybrid tuner is a smart choice and why its manual ECSS is a superior feature.

It is a $300 “prosumer” tool. It demands a learning curve. But for the listener willing to master it, it offers a “complete package” of high-quality build, Air Band capability, and a best-in-class analog signal path for the serious work of exploring the airwaves.