Under the transcript, headed DETECTED CALLSIGNS:, every callsign heard in
it with the name and location on its licence.
Finding them is not one regular expression over the text as written. A
speech recogniser is poor at callsigns -- they are not words, they are
said one character at a time -- so it breaks them wherever the speaker
paused and writes the phonetic alphabet down verbatim. The recording that
prompted this has "Alright, KU 0W" in it, with a space; spelled out it
would have been "kilo uniform zero whiskey". All three forms read back to
KU0W.
Not inventing them matters more. A run of words is accepted only when
none of its parts is an ordinary English word: "or 3. Can you open 4" and
"CC1 boy", both from real transcripts here, fit the shape once the
punctuation is gone and are not callsigns. A single token said in one
breath is still trusted, because W1BOY is a perfectly good callsign, and a
lone "a" or "i" cannot start a join or "a B4U player" becomes AB4U.
Across the 126 transcripts in the recordings directory that turns three
candidates into the one that was actually said.
Lookups use the FCC's own licence data at callook.info -- no account, no
key, the callsign the only thing sent. They never delay the display: the
entry reads "looking up" and fills itself in, and results are cached under
~/.cache so a net recorded night after night is looked up once.
--no-lookup contacts nothing and still describes a callsign from its own
structure, the ITU prefix giving the country and the digit the US
district, which is also all there is to say for callsigns outside the US.
--callsigns prints everyone who identified themselves and where they were
heard.
Also asked: are transcripts appended to, or overwritten, when another
transmission arrives on the same frequency? Neither could be shown from
reading the code alone, so there are now three tests that run real scans
and look at the files. By default each transmission has a transcript of
its own -- the timestamp is in the name, so two overs cannot land on one
file. With --combine there is one recording per frequency and therefore
one transcript, opened for append with the time of each over; a second
scan into the same directory adds to it rather than starting it over,
which is the case the last of the three tests covers.
The browser and callsign tests refuse to reach the network at all. One
test did, quietly, and passed -- visible only because the assertion it
failed printed a real operator's address.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
A long scan leaves hundreds of recordings, each with a JSON sidecar of
measurements and, where a recogniser heard speech, a transcript. Reading
that meant opening files one at a time and guessing which were worth
playing.
saunterbrowse is a second executable in the same package. Arrow keys move
through the recordings; the transcript of whichever is highlighted fills
the top of the screen, because that is the part anyone actually wants to
read. Enter plays it, handing the file to whichever player is installed
-- the recordings are ordinary WAVs, every desktop already has something
that plays them, and a browser that cannot start would be worse than one
that cannot play. t opens the whole transcript full screen when it is
longer than the panel, and says so rather than cutting the end off
silently. / filters on the frequency, the name, the identification, or
anything that was said, which is the point of it: "was the repeater
mentioned" is a question about content.
Sidecars are read only for the rows on screen, so a directory of ten
thousand recordings opens instantly. Where there is no transcript the
panel says which of the reasons applies -- Morse (decoded, and shown),
data, a bare carrier, or speech never offered to a recogniser -- because
those want different things done about them. It only ever reads.
Two things were only found by driving it through a real terminal.
sys.stdin.read(1) goes through a buffered text wrapper, which in cbreak
mode waits for more bytes than one keypress provides: the program drew its
first frame and then hung, while tests against a stand-in stream object
passed. It reads the file descriptor now, and the tests drive a pty. And
stopping playback signalled only the direct child, so a player that is a
wrapper script kept the sound going with nothing on screen to stop it; the
whole process group is signalled instead, which is what start_new_session
was there for.
man saunterbrowse ships beside man bandsaunter, and the two point at each
other.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
A trunked system keeps one frequency transmitting a data stream around
the clock so its radios know where each conversation has been put. There
is no speech on it and it never stops, which makes it the strongest and
most useless signal in the band: the scanner parked on 856.561 MHz for
the full record limit, saved four minutes of buzzing, and found it again
on the next sweep.
Five signatures, matched against a constant-envelope stream that never
pauses: 3600 baud two-level (Motorola SMARTNET/SmartZone), 9600 (EDACS),
1200 (MPT-1327), 4800 four-level (P25 or DMR Tier III), 2400 (NXDN).
The first two are believed at once -- nothing else sends at those rates
without pausing. The rest share their shape with a digital voice call on
the same system, so they wait for the carrier to run unbroken past
--control-seconds, longer than a conversation goes without a breath.
Being in a trunked allocation raises confidence but is never required;
trunking is licensed on business pairs all over the spectrum.
One is named on screen, abandoned within a second or so, and its capture
deleted. --keep-control records them for a decoder; --lockout-control
writes them into the lock-out list.
Three things had to be fixed to get there.
The simulator's "pseudo-random" symbols were a counter: multiplying the
symbol index by an odd constant and taking it modulo the level count
returns the low bits, so two-level FSK came out 0,1,0,1. Every FSK test
in the suite was measuring a tone. Its FSK is now shaped the way GFSK
and C4FM shape a stream, too, square-edged keying being a signal no
licensed transmitter would radiate.
The symbol-rate estimator locked onto harmonics -- 3600 baud read as
18000 -- because a transition impulse train is a comb of equal lines; it
now walks down to the fundamental. The squared envelope is no longer a
candidate: it is not a transition signal, and its DC lobe made every
random OOK signal measure ninety baud. The search starts at 200 Hz
rather than 40, below which it was reading drift, which is how a bare
carrier was awarded a symbol rate. And a clean two-level signal counted
zero discriminator levels, because its modes land in the first and last
histogram bin, where find_peaks cannot see them.
Separately: locking out a frequency wrote to the settings file even under
--no-config, which has no settings file by definition. It now writes
only where it read from, and --simulate never writes at all -- an
invented frequency would sit in a real config for ever, skipping whatever
genuine signal happened to land near it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016PsWPTweCT6pwxKngvVxcg
Every setting now carries a paragraph saying what it is in everyday terms
and why someone who does not already speak radio would turn it up, down,
on or off: what the squelch knob actually is, why automatic gain is a bad
idea for scanning, why a bias tee can damage equipment, why setting the
transcription language matters on noisy audio. The menus and
`config --describe` show it alongside the existing technical detail.
packaging/make-man.py generates bandsaunter(1) from that same table, so the
manual cannot document a setting the program lacks or miss one it has --
tests check both, that the page renders through groff without a single
warning, and that the guidance survives into the rendered output. Around
it are hand-written sections on the commands, entering frequencies, the
band plan, lock-outs, the keys during a scan, HF, single sideband, files,
environment variables and worked examples.
The .deb regenerates and installs it rather than shipping a copy, so an
installed manual always matches the installed program.
The README picks up what the last few commits added: the plain display as
a saved setting, what the settings tests now guarantee, and where to read
the manual before installing.
Version is the day's build: 2026-08-22_01.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
No speech recogniser is in Debian, so installing bandsaunter from a .deb
left transcription to a manual pip step on every machine. A repository of
one's own is not bound by archive policy, so build-repo.sh now packages
faster-whisper and the base.en model alongside the application:
bandsaunter the application (Architecture: all)
bandsaunter-transcribe faster-whisper, vendored (amd64)
bandsaunter-model-base-en the model, so nothing reaches the network
The wheels land in /usr/lib/bandsaunter/vendor rather than dist-packages,
and transcribe.py appends that directory to sys.path -- appends, so an
apt-managed numpy or PyYAML still wins and the vendor copy only fills the
gap. Duplicates of what Debian already ships are stripped from the tree.
resolve_model() turns a bare "base.en" into the packaged copy when one is
installed, and leaves it alone to be downloaded when none is.
The app package recommends the other two, so "apt install bandsaunter"
brings the lot and --no-install-recommends still gets just the scanner.
Its postinst explains how to add a recogniser only when there genuinely
is not one -- including the case where apt has already unpacked the
recogniser package but not yet configured it.
Verified with the source tree hidden and no home directory: the packaged
CLI runs, and a real recording transcribes offline from the vendored
engine and packaged model while numpy still resolves to the system one.
apt itself resolves the repository over HTTP and plans all three.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Versions are now the release date and a revision within that day, padded to
two digits so they sort as text: 2026-08-21_01.
Neither packaging system accepts that form, so it is converted at the edge
rather than kept as a second version string that could drift out of step:
PEP 440 forbids dashes and underscores in a release segment, and a Debian
version may not contain an underscore at all. The date and revision in
__init__.py are the single source; pyproject reads the converted form, and
the tests check that pip and dpkg both order releases correctly.
packaging/build-deb.sh builds a .deb with plain dpkg-deb. Every dependency
is already in Debian, so apt resolves the lot; the package also blacklists
the DVB-T driver that would otherwise claim the receiver. Deliberately not
debhelper: the payload is pure Python with nothing to compile, and this way
the build needs nothing installed beyond dpkg.
The speech recognisers are not packaged for Debian and can only come from
pip, so they are suggested rather than depended on -- transcription is off
by default and reports plainly when no recogniser is present.
README now documents every dependency with its package name on Debian,
Fedora and Arch, how to let a user reach the receiver, and how to check the
install worked.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
