I have recently come up with an idea for improving static RDS PS decoding. It’s very simple, we’re using RDS data up to 5-bit correction and each PS character is replaced only with another that has the same error correction level or lower. The Es season is coming, so this might be helpful for some countries that don’t mainly use dynamic PS names – like UK, Sweden, Finland, Germany, Czech Republic, Slovakia… I also added an option to display the RDS PS in greyscale colors depending on the error correction level.

When the PS progressive correction is used, the RDS PS is surrounded with ( ) instead of [ ]. For a quick toggle between previous and new PS decoding mode click right mouse button on the PS text. This feature may speed up reading full RDS PS using corrected data. Once the RDS PS is decoded without any errors, it will prevent random errors in the station name. This is very helpful for weak tropo signals, see the example of 90.8 Radio 7 in the following video.

For a comparison I recorded some scatter receptions using three instances of XDR-GTK software.

  • First window: no error correction at all
  • Second window: 5 bit correction
  • Third window: new „PS progressive correction”
 95.9 |R-ZURNAL|    96.6 | SRO 1  |    89.0 | IMPULS |    90.0 |DR P3   |
101.7 |R-DVOJKA|    97.6 | ANTENA |    95.9 |  LR-1  |    97.0 |  OE 1  |
105.5 |EVROPA 2|   104.0 |FUNRADIO|    90.8 |RADIO 7 |    89.9 |R-DVOJKA|
 97.7 | KISS JC|   106.0 |EUROPA 2|    91.5 |  LR-2  |
 93.1 |R-ZURNAL|   100.8 | ANT MV |    93.0 |SR P1   |

0A/0B groups contain RDS Programme Service. If we want to extract PS characters we need „Group type code” (4 bits in 2nd block), „Prog. service name” (2 bits in 2nd block) and „Programme service name segment” (2 * 8 bits in 4th block). So, we only need 6 bits from 2nd block and all 16 bits from 4th block. Because of that, I created a weighted method of calculating the possible error level of each PS character, where the 4th block has higher weight.

For dynamic PS decoding I’m personally using 5-bit correction for 2nd block (Group Type / Position) and 2-bit correction for 4th block (Data). This is the default setting in XDR-GTK.

Download new version on the XDR-GTK page. XDR-I2C update is not required this time.

rds0A

Also, welcome to FMDX.pl! This website is mostly in Polish language, but I’ll surely write some English articles in the future about interesting tropo events, so stay tuned.

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