PC2RadioA headphone socket is not enough information
An interface can play music perfectly and still be unsuitable for FM composite output. MPX includes components above the normal audible range. Check the sample rate, high-frequency response and phase response required by your chosen MPX generator.
A “192 kHz” label is a starting point, not a guarantee. Confirm the actual output path, including the driver mode and any hardware filtering.
Check these five things
- Output format: the intended device and driver must support the required sample rate.
- Bandwidth: check that the analogue output passes the composite signal, not just ordinary music.
- Level: match the interface output to the transmitter’s MPX input specification.
- Signal path: avoid unintended effects, resampling and duplicate pre-emphasis.
- Stability: test the complete setup for dropouts and recovery after a restart.
Set up in a controlled order
- Connect the intended input source and confirm normal programme audio first.
- Choose the correct output device and channel in the software. Keep system notification sounds out of this path.
- Follow the software and transmitter instructions for stereo, pre-emphasis and RDS settings.
- Start with a conservative output level and calibrate using suitable modulation measurement equipment.
- Listen on a receiver and check both stereo reception and station text, then perform a sustained operating test.
The application’s dBFS meter measures digital level. It does not measure FM deviation or prove compliance at the transmitter output.
If the result sounds wrong
Distortion: check output clipping, transmitter input level and repeated processing. No stereo: check the selected input, pilot settings and output bandwidth. No RDS: check encoding, injection and receiver support. Dropouts: inspect audio-device settings and system load before changing the transmitter.
Change one setting at a time and keep a known-good configuration. This makes fault-finding much faster than adjusting several controls together.
Get a compatibility check
Ask PCS about your exact interface and transmitter →
Use the current documentation for your exact MPX generator, audio interface and transmitter when checking compatibility.
Let’s check your setup.
Send your transmitter model, operating system, audio interface and whether the transmitter is local or remote.
Email demerzel@pcs-electronics.com →Advice, product prices and orders are handled by PCS Electronics.