diff --git a/src/rcutils.py b/src/rcutils.py
index 696a39d..df7356b 100644
--- a/src/rcutils.py
+++ b/src/rcutils.py
@@ -130,106 +130,6 @@ def probe_radiacode_devices() -> None:
         )
 
 
-def rcspg_make_header(
-    duration: int,
-    serial_number: str,
-    start_time: Number,
-    name: str = "",
-    comment: str = "",
-    flags: int = 1,
-    channels: int = 1024,
-) -> str:
-    """
-    Create the first (header) line of the spectrum file
-
-    Not all flag values are known, but bit 0 being unset means that the
-    spectrogram recording was interrupted and resumed.
-    """
-
-    start_time = float(start_time)  # accept reasonable inputs: 1700000000, 1.7e9, "1.7e9", ...
-    file_time = UnixTime2FileTime(start_time)
-    gt = gmtime(start_time)
-    tstr = strftime("%Y-%m-%d %H:%M:%S", gt)  # This one is for the header
-
-    if not name:
-        # and this version of time just looks like an int... for deduplication
-        name = f"rcmulti-{strftime('%Y%m%d%H%M%S', gt)}-{serial_number}"
-
-    fields = [
-        f"Spectrogram: {name.strip()}",
-        f"Time: {tstr}",
-        f"Timestamp: {file_time}",
-        f"Accumulation time: {int(duration)}",
-        f"Channels: {channels}",
-        f"Device serial: {serial_number.strip()}",
-        f"Flags: {flags}",
-        f"Comment: {comment}",
-    ]
-    return "\t".join(fields)
-
-
-def rcspg_make_spectrum_line(x: Spectrum) -> str:
-    """
-    The second line of the spectrogram is the spectrum of the accumulated exposure
-    since last data reset.
-    (duration:int, coeffs:float[3], counts:int[1024])
-    """
-    v = struct_pack("<Ifff1024I", int(x.duration.total_seconds()), x.a0, x.a1, x.a2, *x.counts)
-    v = hexlify(v, sep=" ").decode()
-    return f"Spectrum: {v}"
-
-
-def rcspg_format_spectra(data: List[SpecData]) -> str:
-    """
-    Given the list of SpecData, convert them to whatever we need for the spectrogram
-
-    data[0] = all-time accumulated spectrum - survives "reset accumulation"
-    data[1] = current accumulated spectrum at the start of measurement. needed to compute
-    data[2:] = the rest of the spectra
-    """
-    lines = []
-    prev_rec = data[1]
-    for rec in data[2:]:
-        ts = rec.time
-        line = [UnixTime2FileTime(ts), int(ts - prev_rec.time)]
-        line.extend([int(x[0] - x[1]) for x in zip(rec.spectrum.counts, prev_rec.spectrum.counts)])
-        prev_rec = rec
-        line = "\t".join([str(x) for x in line])
-        line = re_sub(r"(\s0)+$", "", line)
-        lines.append(line)
-
-    return "\n".join(lines)
-
-
-def rcspg_save_spectrogram_file(
-    data: List[SpecData],
-    serial_number: str,
-    prefix: str = "rcmulti_",
-) -> None:
-    """
-    Emit a spectrogram file into the current directory.
-    """
-    duration = data[-1].time - data[2].time
-    start_time = data[0].time
-    time_string = strftime("%Y%m%d%H%M%S", gmtime(start_time))
-    fn = f"{prefix}{serial_number}_{time_string}.rcspg"
-
-    header = rcspg_make_header(
-        duration=duration,
-        serial_number=serial_number,
-        start_time=start_time,
-    )
-    print(f"saving spectrogram in {fn}")
-
-    tfd, tfn = mkstemp(dir=".")
-    os.close(tfd)
-    with open(tfn, "wt") as ofd:
-        print(header, file=ofd)
-        print(rcspg_make_spectrum_line(data[-1].spectrum), file=ofd)
-        print(rcspg_format_spectra(data), file=ofd)
-    os.rename(tfn, fn)
-
-
 def specdata_to_dict(data: SpecData) -> Dict[str, Any]:
     "Turn a SpecData into an easily jsonified dict"
     rec = {