Radio Data System (RDS) > PIRA32 RDS Encoder
Lexus car radio issue
radiowavesokc:
Hi. I have an odd situation happening when I try to add RDS to one of my sites. I have a listener with a Lexus 2004 car radio that is suddenly getting some audio clip/drop outs while I'm encoding RDS. I have at first tried a Inovonics encoder and now a Pira32 encoder. We have an Orban 8100A XT/2 processor feed to the transmitter via a composite STL. I have the encoder at the transmitter site. I am sampling the composite for the stereo pilot lock via just a BNC splitter right off the back of the STL receiver. The output of the RDS encoder is wired to the SCA input of the exciter. The exciter is a Harris THE-1. I have ensured that I am not in loop mode where the MPX is being passed through the RDS encoder.
What the heck am I doing wrong?
Thanks!
PR
Jan:
The car radio is probably searching for alternative frequencies for your station. It stops playing your station for a while in order to quickly tune to other frequencies. Your audio broadcast is still continuous.
What you can try?
1) Maybe your RDS signal is transmitted at low modulation level (2 kHz or less) so that the receiver considers the reception as bad and errorneous and tries searching for better frequency.
2) If your station has only one transmitter, the second PI digit must be zero (x0xx). The PI is set to FFFF from factory on the encoder!
3) If your station has more transmitters, make sure only the nearest alternative frequencies are placed in AF list on each RDS encoder.
4) Maybe you've changed your PI after the listener stored your station into the receiver's preset memory. In that case the listener must manually tune and store the station into the preset memory again otherwise the receiver tries to find the original station that was first stored.
radiowavesokc:
The car radio is probably searching for alternative frequencies for your station. It stops playing your station for a while in order to quickly tune to other frequencies. Your audio broadcast is still continuous.
I've taken all the other AFs out of this station's list. All that remains is the actual frequency the encoder is on now. The listener confirmed that the drop-out still occurs.
What you can try?
1) Maybe your RDS signal is transmitted at low modulation level (2 kHz or less) so that the receiver considers the reception as bad and errorneous and tries searching for better frequency.
I'm running about 3.75% RDS level. That's 2.8k deviation. I'll try increasing it and testing with the listener to see if more level cures the issue.
2) If your station has only one transmitter, the second PI digit must be zero (x0xx). The PI is set to FFFF from factory on the encoder!
My PI generated is 2158 (hex). I'm in the US. Should I still try changing it to somehting with a 0 on the second digit to ensure that's not tricking the Lexus radio?
3) If your station has more transmitters, make sure only the nearest alternative frequencies are placed in AF list on each RDS encoder.
To test things, I've actually changed the PI to the real call sign of this transmitter. On both the mothership that's not having the issue and this transmitter site I've change the AF to only list that transmitter frequency. The result is still the same (dropout issue)
4) Maybe you've changed your PI after the listener stored your station into the receiver's preset memory. In that case the listener must manually tune and store the station into the preset memory again otherwise the receiver tries to find the original station that was first stored.
I have had the listener tune his radio up to another station via the dial and then back down to me. the drop-out still occurs. Maybe there is still something left in the memory of the radio that might be affecting things?
Thanks!
PR
Jan:
PI meaning is different for European and US standard. There's everything correct on the RDS encoder but maybe the car radio is set to European standard, so that PI 2158 means that there are different AF's (no matter if they are placed in AF list or not).
The final solution must be made on the receiver's side. Switch it to US mode (if possible), turn off any searching. There's not only AF searching. The car radio may also periodically tune all preset stations and search for traffic announcement. If there's some user manual, it should help. Or some kind of reset?
Many receiver's functions and features are not defined in RDS/RBDS standard, so they cannot be affected from the RDS encoder's side. Only make sure you've set TP=1, TA=0, PTY>0.
radiowavesokc:
Thanks!
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