Why you can't always believe RDS Decoder

[Dave-OR]

Hi,

I've been meaning to write an article on RDS for awhile (hi Russ :-)).
I just haven't had the time to do it. So I think I'll put some tidbits up here on the forums which may be helpful to others.

Check out the attached screen capture.

How many station are represented in the main display of RDS Decoder? It looks like one, but it's not. There are actually three stations here:

KDLO Watertown SD (the PS, RT, and CT)
KKMG Pueblo CO (the PTy)
KWFX Woodward OK (the PI)

It's possible - common even - for the PTy to reset without resetting the other data. Obviously, it's also possible for the PI to stay static through resets of the other data. So when reporting to sources like rdslist.com, be sure that you have "pure" data. Generally, I reset the main display each time I've captured what I need. I didn't do so this time and, well. you see the results of my Perseids Ms dxing, at least the RDS portion of it.

Dave Williams
Redmond, OR

[Russ-PA]

I note something else in your screen shot which is also not uncommon.

Note in the top window of the display, on row 0A, column Cnt A the value displayed is "2EA6". Now note the second window, where the most recent PI hits show "2BA6". These values are concurrent values for the most recent hit, but they differ by one character.

This could be due to weak signal, or multiple signals. Hard to tell, but I've seen that from time to time.

As Dave notes, you can get all sorts of strange readouts if you have two RDS signals coming in at the same time, depending on which one dominates at any particular second...

[Russ-PA]

I just experimented a bit with a couple of locals. Looks like I'm getting about 6 hits per second on the Esslinger software, usually 2 each on 0A, 2A and 8A. That way the screens only hold about 30 seconds' worth of data.

On a typical Es signal, you're unlikely to get 6 hits per second, as I couldn't even do it on other locals, but the idea is that in decent Es in unattended mode, you could be losing a lot. So I checked a couple of recent Es screen prints I'd made, and it looks like 2 to 4 hits per second recorded on the software, which would translate into about 45 to 60 seconds' worth on a solid Es signal.

I don't know anything about any of the other RDS softwares, but I could be persuaded to switch very quickly if they had either a larger capacity for
retaining the data, or had some other option to cache it for later recall.

[Russ-PA]

Attached are 3 screen-captures from an Es session earlier this season. For much of the time there were 4 or 5 stations in the mox on 92.9, 3 of which resulted in RDS hits. These shots show how information from multiple stations can be mixed.They also show that with strong Es signals, the RDS data streams are being recorded multiple times within a few seconds.