GopherTrunk

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permalink: /llms.txt
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# GopherTrunk

> GopherTrunk is a pure-Go software-defined-radio (SDR) scanner engine that follows
> and decodes digital trunked-radio voice calls (P25, DMR, TETRA, NXDN, Motorola,
> EDACS, LTR, MPT 1327, dPMR, D-STAR, YSF) from RTL-SDR, HackRF, and Airspy hardware.
> The site also hosts a free, structured learning path that teaches radio and SDR
> fundamentals from beginner to expert.

## Learn

Free, structured curricula taking a complete newcomer to a confident
practitioner. Browse: {{ '/learn/' | absolute_url }}

### Learning paths (optional guides)

Each Learning Path recommends an ordered set of modules toward competence in a
broad domain. Guidance only — no module is required.
{% for lp in site.data.learn.learning_paths %}- [{{ lp.label }}]({{ '/learn/paths/' | append: lp.id | append: '/' | absolute_url }}): {{ lp.tagline }}
{% endfor %}
{% for path in site.data.learn.modules %}{% assign base = '/learn/' | append: path.id | append: '/' %}
## Learn {{ path.label }} (learning module)

{{ path.intro }}
Start: {{ base | absolute_url }}
{% for unit in path.units %}
### {{ unit.label }}
{{ unit.blurb }}
{% for lesson in unit.lessons %}- [{{ lesson.title }}]({{ base | append: lesson.slug | append: '/' | absolute_url }}): {{ lesson.summary }}
{% endfor %}{% endfor %}{% if path.glossary %}### Glossary
- [{{ path.glossary.title }}]({{ base | append: 'glossary/' | absolute_url }}): {{ path.glossary.summary }}
{% endif %}{% endfor %}

## Field Guide

Long-form reference articles defining radio, SDR, and software-development
terms, technologies, algorithms, languages, concepts, people, hardware, and
organizations. Browse: {{ '/reference/' | absolute_url }}
{% for d in site.data.reference.domains %}
### {{ d.label }}
{% for cat in d.categories %}
#### {{ cat.label }}
{% for e in cat.entries %}- [{{ e.title }}]({{ '/reference/' | append: e.slug | append: '/' | absolute_url }}){% endfor %}
{% endfor %}{% endfor %}

## Getting started with GopherTrunk
- [What is GopherTrunk?]({{ '/getting-started.html' | absolute_url }}): conceptual overview of the scanner and its interfaces.
- [Get started]({{ '/getting-started-setup.html' | absolute_url }}): from a dongle to your first decoded call.
- [Hardware]({{ '/hardware.html' | absolute_url }}): supported SDR dongles.
- [Downloads]({{ '/downloads.html' | absolute_url }}): builds for Linux, macOS, and Windows.

## What's happening near me (sirens, lights & incident lookups)
Practical, honest guides for the moment someone hears sirens or sees emergency lights and wants to know what's going on — every lookup method ranked by speed, with clear notes on coverage gaps, delays, and encryption.
- [Why are there sirens near me right now?]({{ '/sirens-near-me/' | absolute_url }}): the fastest ways to find out what's happening — scanner feeds, CAD call logs, incident apps — ranked by how quickly they answer.
- [Police activity near me]({{ '/police-activity-near-me/' | absolute_url }}): live dispatch audio, active-calls pages, crime maps, and public records, with what each one misses.
- [Fire trucks on my street, but no fire]({{ '/fire-trucks-near-me/' | absolute_url }}): why engines respond to medical calls, alarms, and gas odors, and why so many units show up at once.
- [Why is a helicopter circling my neighborhood?]({{ '/helicopter-circling-my-neighborhood/' | absolute_url }}): identify the exact aircraft in under a minute with ADS-B Exchange and read its flight pattern.
- [What different siren sounds mean]({{ '/what-do-siren-sounds-mean/' | absolute_url }}): wail, yelp, phaser, the hi-lo evacuation tone, the fire Q, and the low-frequency Rumbler.
- [Why are the tornado sirens going off?]({{ '/tornado-sirens-going-off/' | absolute_url }}): outdoor warning siren activations, test schedules, and why silence is not an all-clear.
- [How to listen to police scanners online free]({{ '/listen-to-police-scanner-online/' | absolute_url }}): Broadcastify and scanner apps, plus the honest limits — coverage, delays, encryption.
- [What happened near me last night?]({{ '/what-happened-near-me-last-night/' | absolute_url }}): reconstruct an incident after the fact from scanner archives, CAD logs, flight tracks, and records.
- [Accident near me]({{ '/accident-near-me/' | absolute_url }}): dispatch audio, 511/DOT maps, and traffic apps, and how to read crash severity from the response.
- [Why is the road closed?]({{ '/road-closed-near-me/' | absolute_url }}): finding the cause and likely duration of a closure, from crashes to wires down to planned events.
- [Gunshots or fireworks?]({{ '/gunshots-or-fireworks/' | absolute_url }}): the honest by-ear guidance, when to call 911, and how to hear what responding officers actually found.
- [What's burning near me?]({{ '/whats-burning-near-me/' | absolute_url }}): smoke-investigation dispatch calls, wildfire and air-quality maps, and prescribed-burn schedules.
- [Power outage near me]({{ '/power-outage-near-me/' | absolute_url }}): outage maps, the radio traffic that names the cause, and staying informed when the Wi-Fi is down.
- [That loud phone alert]({{ '/emergency-alert-just-went-off/' | absolute_url }}): Wireless Emergency Alerts explained — types, recovering a dismissed alert, and the detail the message leaves out.
- [What was that loud boom?]({{ '/loud-boom-near-me/' | absolute_url }}): transformers, sonic booms, blasting, frost quakes — and the dispatch "area check" that settles it.
- [Ambulance at a neighbor's house]({{ '/ambulance-at-neighbors-house/' | absolute_url }}): what the response pattern means, what stays private and why, and what a good neighbor does.
- [SWAT in my neighborhood]({{ '/swat-team-in-my-neighborhood/' | absolute_url }}): warrant services vs standoffs, what to do while it's active, and the honest limits of what a scanner can hear.
- [Drone flying over my house]({{ '/drone-flying-over-my-house/' | absolute_url }}): identify any drone with free Remote ID apps, police drone programs, and the legal lines in both directions.
- [Military jets flying over]({{ '/military-jets-flying-over-my-house/' | absolute_url }}): training routes, refueling orbits, and why fighters don't show on flight trackers.
- [Why train horns keep blowing]({{ '/train-horns-blowing/' | absolute_url }}): the required horn pattern, stuck crossing gates and the blue-sign number, and quiet zones.
- [Why is the school on lockdown?]({{ '/school-lockdown-near-me/' | absolute_url }}): lockdown vs secure vs hold, why not to drive to the school, and reunification.
- [Water main breaks]({{ '/water-main-break-near-me/' | absolute_url }}): sudden pressure loss, boil-water advisories, brown water, and hydrant flushing false alarms.
- [Did we just have an earthquake?]({{ '/did-we-just-have-an-earthquake/' | absolute_url }}): the 30-second USGS check, the impostor list, and the drop-cover-hold drill.
- [Police checkpoint or roadblock]({{ '/police-checkpoint-near-me/' | absolute_url }}): DUI checkpoints vs manhunt perimeters vs closures, and what each expects of a driver.
- [Why did police knock on my door?]({{ '/police-knocked-on-my-door/' | absolute_url }}): canvassing, welfare checks, wrong addresses — and how to verify a knock is real.
- [Missing-person search near me]({{ '/missing-person-search-near-me/' | absolute_url }}): how searches work, and the three neighbor actions that actually find people.

## Police scanner buyer's guides & hardware
Consumer scanner hardware (Uniden, Whistler) compared honestly against a free SDR + GopherTrunk.
- [Best police scanners]({{ '/best-police-scanners/' | absolute_url }}): buyer's guide to every scanner worth owning, with an honest SDR comparison.
- [Police scanner vs GopherTrunk (SDR)]({{ '/police-scanner-vs-sdr/' | absolute_url }}): where dedicated hardware wins and where free software wins.
- [How police scanners work]({{ '/how-police-scanners-work/' | absolute_url }}): trunking, talkgroups, P25/DMR/NXDN in plain language.
- [Police scanner encryption explained]({{ '/police-scanner-encryption/' | absolute_url }}): why no scanner (or SDR) can decode AES, and what stays open.
- [Is a police scanner legal?]({{ '/police-scanner-legal/' | absolute_url }}): federal and state law on owning and using a scanner.
- [Scanner frequencies by service]({{ '/scanner-frequencies/' | absolute_url }}): police, fire, EMS, aviation, marine, and railroad band plans.
- [How to program a police scanner]({{ '/how-to-program-a-police-scanner/' | absolute_url }}): zip-code, manual, and software programming.
- [Best scanner antennas]({{ '/best-scanner-antenna/' | absolute_url }}): indoor, outdoor, and mobile antennas that fix weak reception.
- [Digital vs analog scanners]({{ '/digital-vs-analog-scanner/' | absolute_url }}): what you can still hear on an analog radio in 2026.
- [P25 scanners]({{ '/p25-scanner/' | absolute_url }}): what Phase I/II and simulcast mean for buyers.

## Ham radio buyer's guides
Amateur radio transceivers ranked with an honest rubric — no star ratings — plus classic used-market picks. Transmitting requires an FCC amateur license; listening does not.
- [Best ham radio base stations]({{ '/best-ham-radio-base-stations/' | absolute_url }}): the 10 best HF base stations ranked, from the Xiegu G90 to the Icom IC-7610, including classic used rigs.
- [Best mobile ham radios]({{ '/best-mobile-ham-radios/' | absolute_url }}): the 10 best vehicle-mount rigs ranked, from budget dual-banders to the Yaesu FTM-500DR, including discontinued do-everything classics.
- [Best handheld ham radios]({{ '/best-handheld-ham-radios/' | absolute_url }}): the 10 best HTs ranked, from the Baofeng UV-5R to the Kenwood TH-D75A, including used-market classics.

## Consumer two-way radio buyer's guides
FRS/GMRS walkie-talkies, GMRS mobile rigs, and CB radios ranked with the same honest rubric — no star ratings. GMRS takes a $35 no-test FCC license; FRS and CB are license-free.
- [Best walkie-talkies]({{ '/best-walkie-talkies/' | absolute_url }}): the 10 best FRS and GMRS handhelds ranked, from the Baofeng GM-15 Pro to the Rocky Talkie 5 Watt, including discontinued classics.
- [Best GMRS mobile radios]({{ '/best-gmrs-mobile-radios/' | absolute_url }}): the 10 best GMRS mobile and base rigs ranked, from the Radioddity DB20-G to the Midland MXT575 and Wouxun KG-1000G Plus.
- [Best CB radios]({{ '/best-cb-radios/' | absolute_url }}): the 10 best CB radios ranked, from the Uniden PRO505XL to the Bearcat 880 and President McKinley, including collector classics.

## Shortwave & emergency radio buyer's guides
Portable and desktop shortwave receivers plus emergency crank/solar radios, ranked with the same honest rubric — all listen-only, no license ever.
- [Best shortwave radios]({{ '/best-shortwave-radios/' | absolute_url }}): the 10 best portable shortwave receivers ranked, from the Tecsun PL-330 to the PL-990 and Sangean ATS-909X2, including discontinued classics.
- [Best emergency radios]({{ '/best-emergency-radios/' | absolute_url }}): the 10 best crank/solar emergency radios ranked, with honest notes on tone alerts vs NOAA SAME and real crank runtimes.
- [Best desktop shortwave receivers]({{ '/best-desktop-shortwave-receivers/' | absolute_url }}): the classic tabletop receivers worth buying used — Drake R8B, Icom IC-R75 — plus the few still made new.

## SDR hardware for GopherTrunk (buyer's guides)
The receivers, antennas, cables, and accessories to run GopherTrunk, with honest picks and Amazon links.
- [Best SDR for GopherTrunk]({{ '/best-sdr-for-gophertrunk/' | absolute_url }}): RTL-SDR, NESDR, Airspy, and HackRF compared for P25/DMR/NXDN decoding.
- [What hardware do I need to run GopherTrunk?]({{ '/what-do-i-need-for-gophertrunk/' | absolute_url }}): the complete dongle + antenna + adapter + computer checklist.
- [Best RTL-SDR for scanning]({{ '/best-rtl-sdr/' | absolute_url }}): which RTL-SDR dongle to buy (and why the V4 is end-of-line).
- [Airspy vs RTL-SDR vs HackRF]({{ '/airspy-vs-rtl-sdr-vs-hackrf/' | absolute_url }}): choosing a receiver by use case.
- [Best SDR antenna]({{ '/best-sdr-antenna/' | absolute_url }}): dipole kits, discones, and mounting for better reception.
- [SDR cables & connectors]({{ '/sdr-cables-and-connectors/' | absolute_url }}): SMA/BNC/N/F/UHF adapters and coax.
- [Best LNA for SDR]({{ '/best-sdr-lna/' | absolute_url }}) and [SDR filters]({{ '/sdr-filters/' | absolute_url }}): fixing weak signals and overload.
- [Best SDR for HF]({{ '/best-hf-sdr/' | absolute_url }}): Airspy HF+ and upconverters for shortwave/ham.
- [Run GopherTrunk on a Raspberry Pi]({{ '/raspberry-pi-sdr-scanner/' | absolute_url }}): 24/7 headless decoding.
- [Best SDR for P25 trunking]({{ '/best-sdr-for-p25-trunking/' | absolute_url }}) and [multi-dongle setups]({{ '/multi-dongle-sdr-setup/' | absolute_url }}): single-site vs wideband multi-site.
- [Cheapest way to scan digital radio]({{ '/cheap-sdr-scanner/' | absolute_url }}): a $30 SDR beats a $380 digital scanner.
- [Best single-board computer for GopherTrunk]({{ '/best-single-board-computer-for-gophertrunk/' | absolute_url }}): Raspberry Pi 5/4/Zero 2 W, Orange Pi 5, Radxa Rock 5B, ODROID, and Le Potato compared as GopherTrunk hosts.

## Technical docs
- [Architecture]({{ '/architecture.html' | absolute_url }}): how the engine is built.
- [Vocoders]({{ '/vocoders.html' | absolute_url }}): IMBE and AMBE+2 voice decoding.
- [Status]({{ '/status.html' | absolute_url }}): protocol and decoder coverage.

## More
- [Full site map]({{ '/sitemap/' | absolute_url }}): a browsable index of every page on the site.
- [Blog]({{ '/blog/' | absolute_url }}): release notes, deep dives, and build-in-the-open posts.