Troubleshooting and Limits

Troubleshooting and Current Limits

Receiver is not listed

• Press Hardware → Refresh after reconnecting.
• Put a PortaPack in HackRF USB mode.
• Use a known data-capable cable and direct/powered USB connection.
• Close other SDR programs that may own the device.
• Follow the card's Install or How-to action.

Every frequency appears active or Overloaded remains on

1. Turn the RF amplifier off.
2. Set LNA/VGA or general gain low.
3. Enable DC removal.
4. Stop and restart the receiver to reset stream state.
5. Raise Mapper's noise margin or squelch.
6. Reconnect without an antenna and compare the noise floor.

An internal center spike or broad overload is not a real transmission. Save calibration only after the baseline is normal.

Static but no intelligible audio

• Use WFM for broadcast FM, AM for aviation/broadcast AM, or NFM for common land-mobile voice.
• Open squelch temporarily.
• Check top-bar mute/volume and row mute/solo.
• Confirm Listen VFO is inside the Hardware center passband.
• Reduce excessive gain and verify the antenna covers the band.

Waterfall or audio is sluggish

• Close competing SDR software.
• Check dropped-block and USB health notices.
• Reduce waterfall frame rate and detail first.
• Reduce sample rate if the stream still drops.
• Disable unnecessary simultaneous decoder jobs.
• Use a powered USB controller/hub when multiple SDRs are unstable.

P25 does not lock

• Verify the control channel is current and belongs to the intended site.
• Confirm frequency/PPM calibration with a known signal.
• Match antenna coverage to the control-channel band.
• Adjust gain for clean frames rather than maximum displayed level.
• Look for NAC/WACN/system identity and grants; RF energy alone is insufficient.

P25 locks but voice is silent or robotic

• Create/verify JMBE for unencrypted calls.
• Check encryption, talkgroup mute/solo, and master audio.
• Turn HackRF amplifier off and reduce overload.
• Watch dropped blocks and reduce capture width if necessary.
• Add a second receiver for more voice capacity.
• Compare the same signal in SDR++ with equivalent RF settings.

Mapper does not find useful activity

• Use a band-appropriate antenna and a smaller test range first.
• Match step and mode to the service.
• Increase dwell for intermittent channels.
• Verify a known signal in Tuner before a wide sweep.
• Remember that Discovery loops and its ETA is per pass.
• Use Identify for longer listens, decoding, and transcription.

Clear or Delete appears ineffective

Current builds use an in-app confirmation dialog. Delete job removes saved job settings but keeps results. Clear results removes observation history but keeps jobs. Cancel intentionally changes nothing.

Current external or engineering limits

• Encrypted P25 is identified and skipped, not decrypted.
• GP-SDR 1.1.x is receive-only; HackRF transmit controls are intentionally not implemented.
• RadioReference live API use needs Premium access and an approved application key; official local exports work without one.
• macOS public packages are ad-hoc signed and not notarized; Windows packages are not Authenticode-signed.
• Soapy hardware, remote servers, optional decoders, and live RF results depend on their driver, local hardware, antenna, and signals.
• DCS subtone decoding and broader adjacent-channel rejection testing remain future work.

When reporting a problem, include OS/CPU, receiver model, antenna band, center and Listen VFO, sample rate, mode/bandwidth, gains/amplifier, squelch, displayed noise/SNR, dropped-block count, and whether the same signal works in SDR++.