This Claude skill provides a comprehensive interface for managing WaveCap-SDR radio settings, enabling precise control over frequency, gain, squelch, and demodulation modes. It streamlines the process of optimizing signal reception and configuring hardware parameters through automated API interactions and helper scripts, making it an essential tool for SDR enthusiasts and developers.

When should I use radio-tuner?

radio-tuner is useful in the following scenarios: • Tuning and Channel Configuration: Effortlessly switch between different radio services like FM broadcast, aviation, or amateur bands by adjusting center frequencies and bandwidth settings. • Signal Quality Optimization: Enhance audio clarity and reduce background noise by fine-tuning RF gain, setting squelch thresholds, and configuring Automatic Gain Control (AGC) parameters. • Interference Management: Eliminate unwanted signals and noise by applying notch filters and enabling FM de-emphasis for high-quality audio output in specific environments. • Hardware Troubleshooting and Monitoring: Monitor SDR stability and resolve common issues like IQ overflows or aliasing by following built-in configuration warnings and best practices.

name	radio-tuner
description	Adjust SDR radio settings (frequency, gain, squelch, bandwidth, filters, AGC) in WaveCap-SDR. Use when changing tuning parameters, optimizing reception, or configuring channels.

Radio Tuner for WaveCap-SDR

This skill provides tools to adjust SDR radio settings including frequency, gain, squelch, bandwidth, filters, and AGC parameters.

When to Use This Skill

Use this skill when:

Changing the tuned frequency
Adjusting gain for optimal signal level
Setting squelch threshold to eliminate noise
Configuring channel bandwidth
Enabling/disabling filters (deemphasis, notch, etc.)
Adjusting AGC parameters
Changing demodulation mode

Available Settings

Capture Settings (SDR-level)

Setting	Description	Range
`centerHz`	Center frequency	1 MHz - 6 GHz
`sampleRate`	Sample rate	Device-dependent
`gain`	RF gain	-100 to 100 dB
`bandwidth`	IF bandwidth	0 to sample_rate
`ppm`	Frequency correction	-1000 to 1000
`antenna`	Antenna port	Device-dependent

Channel Settings (Demodulator-level)

Setting	Description	Range
`mode`	Demodulation mode	wbfm, nbfm, am, ssb, raw, p25, dmr
`offsetHz`	Offset from capture center	-50 MHz to +50 MHz
`squelchDb`	Squelch threshold	-120 to 0 dB
`audioRate`	Output audio rate	8000 to 192000 Hz

Filter Settings

Setting	Description	Default
`enableDeemphasis`	FM de-emphasis filter	true (WBFM)
`deemphasisTauUs`	De-emphasis time constant	75 µs (US), 50 µs (EU)
`enableAgc`	Automatic gain control	true
`agcTargetDb`	AGC target level	-20 dB
`agcAttackMs`	AGC attack time	10 ms
`agcReleaseMs`	AGC release time	500 ms
`notchFrequencies`	Notch filter frequencies	[]

Usage Instructions

Step 1: List Current Settings

Get current capture and channel settings:

# Get capture settings
curl http://127.0.0.1:8087/api/v1/captures/c1 | jq

# Get channel settings
curl http://127.0.0.1:8087/api/v1/channels/ch1 | jq

Or use the helper script:

PYTHONPATH=backend backend/.venv/bin/python .claude/skills/radio-tuner/adjust_settings.py \
  --capture c1 --show

Step 2: Adjust Capture Settings

Change frequency:

curl -X PATCH http://127.0.0.1:8087/api/v1/captures/c1 \
  -H "Content-Type: application/json" \
  -d '{"centerHz": 90300000}'

Change gain:

curl -X PATCH http://127.0.0.1:8087/api/v1/captures/c1 \
  -H "Content-Type: application/json" \
  -d '{"gain": 35.0}'

Or use the helper script:

PYTHONPATH=backend backend/.venv/bin/python .claude/skills/radio-tuner/adjust_settings.py \
  --capture c1 \
  --frequency 90.3 \
  --gain 35

Step 3: Adjust Channel Settings

Change squelch:

curl -X PATCH http://127.0.0.1:8087/api/v1/channels/ch1 \
  -H "Content-Type: application/json" \
  -d '{"squelchDb": -50}'

Change mode:

curl -X PATCH http://127.0.0.1:8087/api/v1/channels/ch1 \
  -H "Content-Type: application/json" \
  -d '{"mode": "nbfm"}'

Enable/disable AGC:

curl -X PATCH http://127.0.0.1:8087/api/v1/channels/ch1 \
  -H "Content-Type: application/json" \
  -d '{"enableAgc": true, "agcTargetDb": -20, "agcAttackMs": 10, "agcReleaseMs": 500}'

Step 4: Add Notch Filters

Remove interference at specific frequencies:

curl -X PATCH http://127.0.0.1:8087/api/v1/channels/ch1 \
  -H "Content-Type: application/json" \
  -d '{"notchFrequencies": [1000, 2000, 3000]}'

Helper Script Reference

# Show current settings
python adjust_settings.py --capture c1 --show

# Change frequency (MHz)
python adjust_settings.py --capture c1 --frequency 90.3

# Change gain (dB)
python adjust_settings.py --capture c1 --gain 35

# Change bandwidth (Hz)
python adjust_settings.py --capture c1 --bandwidth 200000

# Change squelch (dB)
python adjust_settings.py --channel ch1 --squelch -50

# Change mode
python adjust_settings.py --channel ch1 --mode nbfm

# Multiple settings at once
python adjust_settings.py --capture c1 --frequency 90.3 --gain 35 --bandwidth 200000

Demodulation Modes

Mode	Description	Typical Use
`wbfm`	Wide-band FM (200 kHz)	FM broadcast radio
`nbfm`	Narrow-band FM (12.5-25 kHz)	Two-way radio, amateur
`am`	Amplitude modulation	Aviation, AM broadcast
`ssb`	Single sideband	Amateur radio, marine
`raw`	No demodulation	Digital modes, ISM
`p25`	Project 25 digital	Public safety
`dmr`	Digital Mobile Radio	Commercial two-way

Optimal Settings by Application

FM Broadcast Radio

{
  "sampleRate": 1024000,
  "bandwidth": 200000,
  "mode": "wbfm",
  "enableDeemphasis": true,
  "deemphasisTauUs": 75,
  "squelchDb": -60
}

VHF Marine / Aviation

{
  "sampleRate": 2000000,
  "bandwidth": 25000,
  "mode": "nbfm",
  "squelchDb": -50,
  "enableAgc": true
}

Amateur Radio SSB

{
  "mode": "ssb",
  "ssbMode": "usb",
  "enableSsbBandpass": true,
  "ssbBandpassLowHz": 300,
  "ssbBandpassHighHz": 3000,
  "squelchDb": -60
}

Configuration Warnings

WaveCap-SDR automatically detects problematic configurations and displays warnings in the UI. Check configWarnings in capture API responses to see current warnings.

Check Current Warnings

curl -s http://127.0.0.1:8087/api/v1/captures/c1 | jq '.configWarnings'

Warning Types

Code	Severity	Description	Resolution
`rtl_unstable_sample_rate`	warning	RTL-SDR sample rate <900kHz causes IQ overflows	Use 1.024 MHz, 2.048 MHz, or 2.4 MHz
`bandwidth_exceeds_sample_rate`	warning	Bandwidth > sample rate violates Nyquist	Reduce bandwidth or increase sample rate
`bandwidth_near_sample_rate`	info	Bandwidth >90% of sample rate causes edge aliasing	Use bandwidth ≤80% of sample rate
`sdrplay_high_sample_rate`	info	SDRplay >8 MHz may cause USB issues	Lower sample rate if experiencing dropouts
`zero_gain`	info	Gain set to 0 dB	Increase gain if signals are weak

Best Practices to Avoid Warnings

RTL-SDR Sample Rates: Use 1.024 MHz, 2.048 MHz, or 2.4 MHz

curl -X PATCH http://127.0.0.1:8087/api/v1/captures/c1 \
  -H "Content-Type: application/json" \
  -d '{"sampleRate": 1024000}'

Bandwidth/Sample Rate Ratio: Keep bandwidth ≤80% of sample rate

# For 2 MHz sample rate, use ≤1.6 MHz bandwidth
curl -X PATCH http://127.0.0.1:8087/api/v1/captures/c1 \
  -H "Content-Type: application/json" \
  -d '{"sampleRate": 2000000, "bandwidth": 1600000}'

SDRplay Sample Rates: Stay ≤8 MHz for reliable USB throughput

curl -X PATCH http://127.0.0.1:8087/api/v1/captures/c1 \
  -H "Content-Type: application/json" \
  -d '{"sampleRate": 6000000}'

Common Issues

Issue: Audio Too Quiet

Solutions:

Increase gain on capture
Increase agcTargetDb (e.g., -15 instead of -20)
Check antenna connection

Issue: Audio Distorted

Solutions:

Reduce gain on capture
Lower agcTargetDb (e.g., -25 instead of -20)
Enable de-emphasis for FM

Issue: Too Much Background Noise

Solutions:

Increase squelchDb (less negative, e.g., -40 instead of -60)
Add notch filters for specific interference
Enable noise blanker

Issue: Signal Cutting In/Out

Solutions:

Lower squelchDb (more negative)
Adjust AGC attack/release times
Check if frequency offset is correct

Issue: IQ Overflows (RTL-SDR)

Solutions:

Use stable sample rate (1.024 MHz, 2.048 MHz, or 2.4 MHz)
Avoid sample rates below 900 kHz
Check USB connection quality

Issue: Aliasing at Spectrum Edges

Solutions:

Reduce bandwidth to ≤80% of sample rate
Increase sample rate if wider bandwidth needed
Use appropriate IF filter settings

Files in This Skill

SKILL.md: This file - instructions for using the skill
adjust_settings.py: Helper script for adjusting radio settings

radio-tuner

When & Why to Use This Skill

Use Cases

Radio Tuner for WaveCap-SDR

When to Use This Skill

Available Settings

Capture Settings (SDR-level)

Channel Settings (Demodulator-level)

Filter Settings

Usage Instructions

Step 1: List Current Settings

Step 2: Adjust Capture Settings

Step 3: Adjust Channel Settings

Step 4: Add Notch Filters

Helper Script Reference

Demodulation Modes

Optimal Settings by Application

FM Broadcast Radio

VHF Marine / Aviation

Amateur Radio SSB

Configuration Warnings

Check Current Warnings

Warning Types

Best Practices to Avoid Warnings

Common Issues

Issue: Audio Too Quiet

Issue: Audio Distorted

Issue: Too Much Background Noise

Issue: Signal Cutting In/Out

Issue: IQ Overflows (RTL-SDR)

Issue: Aliasing at Spectrum Edges

Files in This Skill