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PROBLEM DESCRIPTION
POSSIBLE SOLUTIONS
Mono operation only, no stereo
1. Check supply power and voltage
2. Increase audio level in the FM exciter a little bit
3. Make sure you have disabled pre-emphasis in your FM exciter (set jumper to
NONE).
Very poor stereo separation,
strange audio
1. Make sure you disable pre-emphasis in your FM EXCITER. Check supply voltage
Audio without any treble
Set pre-emphasis on the stereo encoder board (either 50uS or 75uS).
There is HUM in audio
- Try with a different mains power supply.
- Move antenna as far away from the transmitter and audio gear as possible
- Use XLR audio connectors or digital audio, if possible (USB)
- Make sure SWR is low
- Keep audio cables short and away from antenna and RF coaxial cable
- Form a coil from coaxial cable going to the antenna, make a few turns. This stops
RF currents that might be flowing on the outer braid of the coaxial cable. This
usually happens when you connect unbalanced cable to balanced antenna without
proper BALUN (balanced-unbalanced convertor) resulting in coaxial cable
becoming part of the antenna and radiating RF energy as well…causing hum.
Audio too quiet/loud
1. Open or close the MPX input level trimmer on FM transmitter a little bit.
2. Increase or decrease level on your audio source a little bit, start using software or
hardware compressor
Audio too loud
Close the modulation level input trimmer on FM transmitter a little bit.
With no audio connected I can hear
sort of digital noise
- This means RDS carrier is set too high or RDS phase is not adjusted. Set RDS carrier
level to zero with trimmer, than slowly increase until RDS indicator turns on on the
receiver. Than increase a tiny bit more. Now set phase for minimal/no noise. Best done
with no audio input and radio speakers open to max.
- This could also be caused by fan. Stop the fan and see if the noise dissapears
Sometimes/rarely the unit starts in
MONO mode.
Restart the unit, the problem should go away. We have firmware update for this but
you have to send the unit back for update. The problem is rare and only happens at the
start. This firmware issue only affects some SE units. There is also hardware
workaround that involves soldering one resistor and one capacitor. If you want to apply
this, contact us and we’ll guide you to apply the fix.
Power supply is blinking
Probably the same thing as above. Blinking power supply means its protection is
shutting it off and back on, probably due to excessive current draw caused by burned
unit or damaged power supply.
Audio distortion on high peaks, for
example on “s” sound.
Your audio input level is slightly too high, reduce input audio level slightly at your audio
source. Use some kind of compressor to remove over-modulation peaks. Use EQ to
drop levels above 15KHz and below 30Hz.
There is HUM in audio
- Move antenna as far away from the transmitter and audio gear as possible
- Use balanced audio inputs (XLR audio connectors) rather than RCA
- Make sure SWR is low