Band Scanner GPS – FM Band Spectrum & Mod Analyzer, RDS/RBDS Decoder-Reader with built-in GPS Receiver

This is a citation from US RBDS Standard/EN 50067 standard:
Method B AF coding is used where it is required to indicate frequencies that belong to different regions, which may carry different programs.
For the transmission of the frequency pairs within one block the following convention is used:

• They are generally transmitted in ascending order, e.g. 89.3 - 99.5 or 99.5 - 101.8 F1 < F2
• In special cases they are transmitted in descending order, if they belong to different regions, or carry from time to time different programs, e.g. 99.5 - 90.6 or 100.7 - 99.5 F1 > F2

In both of the above examples 99.5 MHz is the tuning frequency.

Examples of a AF method B coding:

F1	F2	Commentary
#11	89.3	Total number (11) of frequencies for tuning frequency (89.3)
89.3	99.5	F2 > F1 hence 99.5 is an AF of tuned frequency 89.3, and it is the same program
89.3	101.7	F2 > F1 hence 101.7 is an AF of tuned frequency 89.3, and it is the same program
88.8	89.3	F2 > F1 hence 88.8 is an AF of tuned frequency 89.3, and it is the same program
102.6	89.3	F2 < F1 hence 102.6 is an AF of a regional variant of tuned frequency 89.3
89.3	89.0	F2 < F1 hence 89.0 is an AF of a regional variant of tuned frequency 89.3
#9	99.5	Total number (9) of frequencies for tuning frequency (99.5)
89.3	99.5	F2 > F1 hence 89.3 is an AF of tuned frequency 99.5, and it is the same program
99.5	100.9	F2 > F1 hence 100.9 is an AF of tuned frequency 99.5, and it is the same program
104.8	99.5	F2 < F1 hence 104.8 is an AF of a regional variant of tuned frequency 99.5
99.5	89.1	F2 < F1 hence 89.1 is an AF of a regional variant of tuned frequency 99.5

You need to make sure first that the Signal Quality has not became very poor. Bad signal quality leads to erroneous RDS reception and then to incorrect Alternative Frequencies (AF) lists. On the other hand, when there are long AF lists in such 'bad' environment, Band Scanner GPS lacks the speed to observe all the AFs correctly, which results in wrong/missing PIs. Also, multiple tasks, together with poor signal reception produce unusual gaps. We recommend that you use RF antenna (installed outside the vehicle) and isolate the problematic station and run campaign only with it. Driving speed is also a factor.

Green flashing LED indicates that Band Scanner GPS has no drivers installed. With a normal installation, the driver will be located here: My Computer/Local Disk (C:)/Program Files/Band Scanner GPS/Drivers. Drivers can be found on the supplied CD also, in the 'Drivers' folder. Driver Installation details are described in DEVA User Manuals, chapter 'Installing the Software'.

Running a campaign depends on many factors. In case of a very slow frequency change, or no change at all, the reasons could be several:

• Bad signal reception - if switch to a frequency with bad signal reception is made, it is obviously a dead end one - due to errors, no information could be collected for a switch to another frequency to take place.
• Too long AF lists (with a short listen time it could not acquire AF list at all) – After observing all frequencies from the list, one that best suits your purposes should be chosen. Bad Signal Reception and PI tracking are yet another factors to influence the frequency change. For more detailed investigation into the possible reasons, you need to know the changeover points (AF lists, PIs, etc.) and to observe the campaign file.

Press the "SET" button. Whenever setting the frequency (same or not) it will clear all of the acquisitions.