RDS Features on Sony XDR-F1HD vs Auvio Feb 2011

Feb 23, 2011 - demonstration of the RDS response/features on the Sony XDR-F1HD and Auvio FM tuners using local signals. The Auvio is a discontinued AM/FM HD tuner that's being offered at a deep discount at Radio Shack. While no great expectations were held for it to be a supberb FM-DX machine like the Sony, some of its features like knob tuning and different RDS display/characteristics were tempting enough.

The locals selected were RDS-only as HD signals with RDS default to the HD display (when strong enough) on both units. Seperate, similar 6-element FM antennas were used on each set aimed in the same direction to provide close equality in signal strengths/quality. The audio was not turned up for these clips as the main intent was the LCD comparison.

89.7 KJMA TX Floresville (100 kw, 40 miles)

91.3 KZLV TX Lytle (50 kw, 18 miles)

92.9 KROM TX San Antonio (45 kw, 24 miles)

103.7 K279AB TX San Antonio (81 w, 3 miles) (translator for KAHL 1310 kHz)

The Sony unit for RDS displays just the PS field (which, if large enough, scrolls and may or may not have the station's actual call letters). The Auvio RDS display contains much more information. The center of the top line is the PI (converted from the 4-digit hexadecimal code into call letters via an internal firmware algorithm). Under the frequency is the RBDS (US) PTY (program type). The bottom line is the Radio Text - which is delayed by the display until the entire string is decoded (that's why the KJMA and KZLV clips are so long). The Auvio display is in many ways more like that found on the Sangean tuners.

Note that the Sony takes nearly 3 seconds to "react" to its limited (PS) RDS information whereas the Auvio is much faster. The Auvio manual seems to indicate that the top line call letter display would be from the PS (often with just a slogan) rather than being PI-derived. For FM-DXers the PI field is a sort of "Holy Grail" as it is sent 11 times more often than much of the other RDS data so that its chances of being decoded completely will be higher with any brief, rapidly fading signals (such as meteor scatter). In fact, much effort has been made by several folk to make PI-decoding hardware that can be retrofitted onto the Sony!

But, as noted earlier, not much was expected from the Auvio in regards to it being a very useful FM-DX machine, and that was sadly proven out with it having poor selectivity and, worse even, being subject to overload intermod spurs and desense in this urban environment. True A/B comparisons (switching antenna systems) had the Sony showing Houston (185 miles) HD station call idents that could barely even be heard on the Auvio. But, at the current $40, it's not a bad deal for local FM HD (and even features coaxial and optical audio-out ports).

Category:

Science & Technology

Tags:

• XDR-F1HD
• Auvio
• RDS
• FM-DX

[xmaddictstechnstuff]

I have 3 RDS Radios. 1; Insignia HD Radio w/RDS. 1: HTC Phone with full RDS. 1: Grundig Ocean Boy 510 with RDS.

The Grundig and Insignia will receive both PT and RT. While the later can only get PT.