diff --git a/_config.yml b/_config.yml
index 32b353393..08636d5cc 100644
--- a/_config.yml
+++ b/_config.yml
@@ -50,5 +50,4 @@ html:
 # Exclude notebooks that have as-yet unresolved build failures (see tickets SPB-1153SPB-1160, SPB-1168)
 exclude_patterns: [notebooks/DrizzlePac/align_mosaics/align_mosaics.ipynb,
                    notebooks/WFC3/dash/dash.ipynb,
-                   notebooks/WFC3/flux_conversion_tool/flux_conversion_tool.ipynb,
                    notebooks/WFC3/zeropoints/zeropoints.ipynb]
diff --git a/notebooks/WFC3/flux_conversion_tool/flux_conversion_tool.ipynb b/notebooks/WFC3/flux_conversion_tool/flux_conversion_tool.ipynb
index 02db84c58..5f256cfad 100644
--- a/notebooks/WFC3/flux_conversion_tool/flux_conversion_tool.ipynb
+++ b/notebooks/WFC3/flux_conversion_tool/flux_conversion_tool.ipynb
@@ -62,10 +62,11 @@
     "<a id=\"imports\"></a>\n",
     "## 1. Imports\n",
     "\n",
-    "This notebook assumes you have created the virtual environment in [WFC3 Library's](https://github.com/spacetelescope/WFC3Library) installation instructions.\n",
+    "This notebook assumes you have created the virtual environment in [WFC3 notebooks’](https://github.com/spacetelescope/hst_notebooks/blob/main/notebooks/WFC3/README.md) installation instructions.\n",
     "\n",
     "We import:\n",
     "- *os* for setting environment variables\n",
+    "- *tarfile* for extracting a .tar archive\n",
     "\n",
     "- *numpy* for handling array functions\n",
     "- *matplotlib.pyplot* for plotting data\n",
@@ -83,21 +84,20 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "%matplotlib notebook\n",
-    "\n",
     "import os\n",
+    "import tarfile\n",
     "\n",
     "import numpy as np\n",
     "import matplotlib.pyplot as plt\n",
     "\n",
-    "import synphot as syn\n",
-    "from synphot import SourceSpectrum, Observation\n",
+    "from synphot import SourceSpectrum\n",
     "from synphot.models import BlackBody1D, PowerLawFlux1D\n",
     "from synphot.units import convert_flux\n",
     "\n",
     "from astropy import units as u\n",
     "from synphot import units as su\n",
     "\n",
+    "%matplotlib inline\n",
     "vegaspec = SourceSpectrum.from_vega() "
    ]
   },
@@ -106,7 +106,7 @@
    "id": "03e60162",
    "metadata": {},
    "source": [
-    "This section obtains the WFC3 throughput component tables for use with `synphot`. If reference files need to be downloaded, please uncomment and execute the code block below."
+    "This section obtains the WFC3 throughput component tables for use with `stsynphot`. This step only needs to be done once. If these reference files have already been downloaded, this section can be skipped."
    ]
   },
   {
@@ -116,8 +116,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# cmd_input = 'curl -O https://archive.stsci.edu/hlsps/reference-atlases/hlsp_reference-atlases_hst_multi_everything_multi_v11_sed.tar'\n",
-    "# os.system(cmd_input)"
+    "cmd_input = 'curl -O https://archive.stsci.edu/hlsps/reference-atlases/hlsp_reference-atlases_hst_multi_everything_multi_v11_sed.tar'\n",
+    "os.system(cmd_input)"
    ]
   },
   {
@@ -125,7 +125,7 @@
    "id": "a60c88ec",
    "metadata": {},
    "source": [
-    "Once the downloaded is complete, unzip the file and set the environment variable `PYSYN_CDBS` to the path of the reference files. To do so, uncomment and execute the relevant line from the code block below. "
+    "Once the downloaded is complete, extract the file and set the environment variable `PYSYN_CDBS` to the path of the `trds` subdirectory.  The next cell will do this for you, as long as the `.tar` file downloaded above has not been moved."
    ]
   },
   {
@@ -135,7 +135,12 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# os.environ['PYSYN_CDBS'] = '/path/to/my/reference/files/'"
+    "tar_archive = 'hlsp_reference-atlases_hst_multi_everything_multi_v11_sed.tar'\n",
+    "extract_to = 'hlsp_reference-atlases_hst_multi_everything_multi_v11_sed'\n",
+    "with tarfile.open(tar_archive, 'r') as tar:\n",
+    "    tar.extractall(path=extract_to)\n",
+    "\n",
+    "os.environ['PYSYN_CDBS'] = 'hlsp_reference-atlases_hst_multi_everything_multi_v11_sed/grp/redcat/trds/'"
    ]
   },
   {
@@ -143,7 +148,7 @@
    "id": "c4bbc869",
    "metadata": {},
    "source": [
-    "Now, after having set up `PYSYN_CDBS`, we import stsynphot."
+    "Now, after having set up `PYSYN_CDBS`, we import stsynphot. A warning regarding the Vega spectrum is expected here."
    ]
   },
   {
@@ -153,8 +158,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "import stsynphot as stsyn\n",
-    "from stsynphot import band"
+    "import stsynphot as stsyn"
    ]
   },
   {
@@ -224,7 +228,7 @@
     "\n",
     "- `synphot.models.BlackBody1D` outputs a function according to Planck's law, which means that the output unit carries an implicit \"per unit solid angle,\" in steradians. For a normalized blackbody, you can use `BlackBodyNorm1D`, whose output is normalized to a 1 solar radius star at a distance of 1 kpc, or multiply your source spectrum by some solid angle of your choosing.\n",
     "\n",
-    "- `synphot.models.PowerLawFlux1D` uses the definition $f(x) = A (\\frac{x}{x_0})^{-\\alpha}$, where $A$ is input flux (`flux_in`), and $x_0$ is the input wavelength (`wl_in`). Note the negative sign in front of the power law index $\\alpha$. The model can generate curves with $x$ as either frequency or wavelength, but the example here assumes that wavelength will be used. The y-axis unit will be taken from $A$. \n",
+    "- `synphot.models.PowerLawFlux1D` uses the definition $f(x) = A (\\frac{x}{x_0})^{-\\alpha}$, where $A$ is input flux (`flux_in`), and $x_0$ is the input wavelength (`wavelength_in`). Note the negative sign in front of the power law index $\\alpha$. The model can generate curves with $x$ as either frequency or wavelength, but the example here assumes that wavelength will be used. The y-axis unit will be taken from $A$. \n",
     "\n",
     "- A wide array of reference spectra are available for download from spectral atlases located [here](https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs).\n",
     "\n",
@@ -237,16 +241,16 @@
     "bb_temp = 5800 * u.K\n",
     "\n",
     "model = BlackBody1D(bb_temp)\n",
-    "spec  = SourceSpectrum(model)\n",
+    "spectrum = SourceSpectrum(model)\n",
     "\n",
     "# Power law \n",
     "pl_index = 0\n",
     "\n",
-    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wl_in, alpha=pl_index)\n",
-    "spec  = SourceSpectrum(model)\n",
+    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wavelength_in, alpha=pl_index)\n",
+    "spectrum = SourceSpectrum(model)\n",
     "                                             \n",
     "# Load from a FITS table\n",
-    "spec = SourceSpectrum.from_file('/path/to/your/spectrum.fits')\n",
+    "spectrum = SourceSpectrum.from_file('/path/to/your/spectrum.fits')\n",
     "```\n",
     "\n",
     "The notebook has been set up to perform an extrapolation from $V = 0.0$ in the Vega system to the R-band in the same system, using the Vega spectrum defined in the imports cell. Further examples of input and output settings are available at the bottom of this notebook.\n",
@@ -255,10 +259,10 @@
     "### 2.4 User settings\n",
     "\n",
     "First, we define our conversion input settings:\n",
-    "- `val_in`: numerical value of input flux/mag (float)\n",
+    "- `value_in`: numerical value of input flux/mag (float)\n",
     "- `unit_in`: unit or mag system for input value\n",
-    "- `wl_bp_in`: input's wavelength (float) for flux, or bandpass obsmode (string) for magnitudes\n",
-    "- `wl_unit`: wavelength unit (used for plots, so needs to be specified even when using a bandpass)"
+    "- `waveband_in`: input's wavelength (float) for flux, or bandpass obsmode (string) for magnitudes. The use of \"waveband\" here is only for the purpose of variable naming, since this can be either a wavelength or a bandpass.\n",
+    "- `wavelength_unit`: wavelength unit (used for plots, so needs to be specified even when using a bandpass)"
    ]
   },
   {
@@ -268,11 +272,10 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "val_in   = 0.0\n",
-    "unit_in  = su.VEGAMAG\n",
-    "wl_bp_in = 'johnson, v'\n",
-    "\n",
-    "wl_unit  = u.nm "
+    "value_in = 0.0\n",
+    "unit_in = su.VEGAMAG\n",
+    "waveband_in = 'johnson, v'\n",
+    "wavelength_unit = u.nm "
    ]
   },
   {
@@ -282,7 +285,7 @@
    "source": [
     "Next, we define our conversion output settings:\n",
     "- `unit_out`: unit or mag system for the output\n",
-    "- `wl_bp_out`: wavelength (float) or bandpass obsmode (string) to find output for; if a wavelength, the unit specified in the cell above by `wl_unit` will be used."
+    "- `waveband_out`: wavelength (float) or bandpass obsmode (string) to find output for; if a wavelength, the unit specified in the cell above by `wavelength_unit` will be used."
    ]
   },
   {
@@ -292,8 +295,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "unit_out  = su.VEGAMAG\n",
-    "wl_bp_out = 'cousins, r'"
+    "unit_out = su.VEGAMAG\n",
+    "waveband_out = 'cousins, r'"
    ]
   },
   {
@@ -311,7 +314,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "spec = vegaspec"
+    "spectrum = vegaspec"
    ]
   },
   {
@@ -344,9 +347,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "quant_in = val_in * unit_in\n",
-    "\n",
-    "mag_systems  = [u.STmag, u.ABmag, su.VEGAMAG]\n",
+    "quantity_in = value_in * unit_in\n",
+    "mag_systems = [u.STmag, u.ABmag, su.VEGAMAG]\n",
     "flux_systems = ['spectral flux density', 'spectral flux density wav', \n",
     "                'photon flux density', 'photon flux density wav']"
    ]
@@ -381,27 +383,18 @@
    "outputs": [],
    "source": [
     "if unit_in in mag_systems:\n",
-    "    \n",
-    "    mag_in = quant_in\n",
-    "    \n",
-    "    band_in = band(wl_bp_in)\n",
-    "    wl_in   = band_in.pivot().to(wl_unit)\n",
-    "    \n",
-    "    flux_in = convert_flux(wl_in, quant_in, su.PHOTLAM,\n",
+    "    mag_in = quantity_in\n",
+    "    bandpass_in = stsyn.band(waveband_in)\n",
+    "    wavelength_in = bandpass_in.pivot().to(wavelength_unit)\n",
+    "    flux_in = convert_flux(wavelength_in, quantity_in, su.PHOTLAM,\n",
     "                           vegaspec=vegaspec)\n",
-    "    \n",
     "    plot_unit = su.PHOTLAM\n",
-    "    \n",
-    "    plot_flux_in = convert_flux(wl_in, flux_in, plot_unit)\n",
-    "    \n",
+    "    plot_flux_in = convert_flux(wavelength_in, flux_in, plot_unit)\n",
     "elif unit_in.physical_type in flux_systems:\n",
-    "    \n",
-    "    flux_in = quant_in\n",
-    "    wl_in   = wl_bp_in * wl_unit \n",
-    "    \n",
+    "    flux_in = quantity_in\n",
+    "    wavelength_in = waveband_in * wavelength_unit \n",
     "    plot_unit = unit_in\n",
-    "    plot_flux_in = convert_flux(wl_in, flux_in, plot_unit)\n",
-    "\n",
+    "    plot_flux_in = convert_flux(wavelength_in, flux_in, plot_unit)\n",
     "else:\n",
     "    print('unit_in not a flux density unit or magnitude system')"
    ]
@@ -429,20 +422,14 @@
    "cell_type": "code",
    "execution_count": null,
    "id": "5928f11f",
-   "metadata": {
-    "scrolled": false
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "if unit_out in mag_systems:\n",
-    "    \n",
-    "    band_out = band(wl_bp_out)\n",
-    "    wl_out = band_out.pivot().to(wl_unit)\n",
-    "\n",
+    "    bandpass_out = stsyn.band(waveband_out)\n",
+    "    wavelength_out = bandpass_out.pivot().to(wavelength_unit)\n",
     "elif unit_out.physical_type in flux_systems:\n",
-    "    \n",
-    "    wl_out = wl_bp_out * wl_unit\n",
-    "\n",
+    "    wavelength_out = waveband_out * wavelength_unit\n",
     "else:\n",
     "    print('unit_out not a flux density unit or magnitude system')    "
    ]
@@ -462,9 +449,8 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "scale = convert_flux(wl_in, flux_in, su.PHOTLAM) / spec(wl_in)\n",
-    "\n",
-    "scale_spec = spec * scale"
+    "scale = convert_flux(wavelength_in, flux_in, su.PHOTLAM) / spectrum(wavelength_in)\n",
+    "scaled_spectrum = spectrum * scale"
    ]
   },
   {
@@ -486,18 +472,14 @@
    "outputs": [],
    "source": [
     "if unit_out in mag_systems:\n",
-    "    \n",
-    "    flux_out = convert_flux(wl_out, scale_spec(wl_out), unit_out,\n",
+    "    flux_out = convert_flux(wavelength_out, scaled_spectrum(wavelength_out), unit_out,\n",
     "                            vegaspec=vegaspec)\n",
-    "    \n",
-    "    plot_flux_out = convert_flux(wl_out, scale_spec(wl_out), plot_unit)\n",
-    "    \n",
+    "    plot_flux_out = convert_flux(wavelength_out, scaled_spectrum(wavelength_out), plot_unit)\n",
     "else:\n",
-    "    flux_out = convert_flux(wl_out, scale_spec(wl_out), unit_out)\n",
+    "    flux_out = convert_flux(wavelength_out, scaled_spectrum(wavelength_out), unit_out)\n",
+    "    plot_flux_out = convert_flux(wavelength_out, scaled_spectrum(wavelength_out), plot_unit)\n",
     "    \n",
-    "    plot_flux_out = convert_flux(wl_out, scale_spec(wl_out), plot_unit)\n",
-    "    \n",
-    "val_out = flux_out.value"
+    "value_out = flux_out.value"
    ]
   },
   {
@@ -515,8 +497,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "print('Input: {:.4} {} at {:.1f} {}\\n'.format(float(val_in), str(unit_in), wl_in.value, str(wl_in.unit)))\n",
-    "print('Output: {:.4} {} at {:.1f} {}'.format(float(val_out), str(unit_out), wl_out.value, str(wl_out.unit)))"
+    "print(f'Input: {value_in:.4f} {unit_in:s} at {wavelength_in.value:.1f} {wavelength_in.unit:s}\\n')\n",
+    "print(f'Input: {value_out:.4f} {unit_out:s} at {wavelength_out.value:.1f} {wavelength_out.unit:s}\\n')\n",
+    "# print(f'Output: {float(value_out):.4} {} at {:.1f} {}'.format(, str(unit_out), wavelength_out.value, str(wavelength_out.unit)))"
    ]
   },
   {
@@ -536,22 +519,17 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "wl_settings = [wl.value for wl in [wl_in, wl_out]]\n",
-    "\n",
-    "short = min(wl_settings)\n",
-    "long = max(wl_settings)\n",
+    "wavelength_settings = [wl.value for wl in [wavelength_in, wavelength_out]]\n",
+    "short = min(wavelength_settings)\n",
+    "long = max(wavelength_settings)\n",
     "\n",
-    "if short == long:  # In case wl_in == wl_out\n",
+    "if short == long:  # In case wavelength_in == wavelength_out\n",
     "    diff = 10.\n",
-    "    \n",
     "else:\n",
     "    diff = long - short\n",
-    "\n",
     "right = long + diff\n",
-    "\n",
     "left = max([short - diff, 0.1])\n",
-    "\n",
-    "waves = np.linspace(left, right, 10000) * wl_unit"
+    "wavelength_space = np.linspace(left, right, 10000) * wavelength_unit"
    ]
   },
   {
@@ -569,11 +547,9 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "if wl_in.value > wl_out.value:\n",
-    "        \n",
+    "if wavelength_in.value > wavelength_out.value:\n",
     "    c_in = 'r'\n",
     "    c_out = 'b'\n",
-    "    \n",
     "else: \n",
     "    c_in = 'b'\n",
     "    c_out = 'r'"
@@ -591,47 +567,39 @@
    "cell_type": "code",
    "execution_count": null,
    "id": "8bea8f73",
-   "metadata": {
-    "scrolled": false
-   },
+   "metadata": {},
    "outputs": [],
    "source": [
     "plt.figure()\n",
     "\n",
     "# Plot spectrum\n",
-    "\n",
-    "plt.plot(waves, scale_spec(waves, flux_unit=plot_unit), c='k')\n",
+    "plt.plot(wavelength_space, scaled_spectrum(wavelength_space, flux_unit=plot_unit), c='k', label='Source Spectrum')\n",
     "\n",
     "# Plot input\n",
-    "\n",
-    "plt.plot(wl_in.value, plot_flux_in.value,\n",
+    "plt.plot(wavelength_in.value, plot_flux_in.value,\n",
     "         marker='o', color=c_in, ls='none', \n",
     "         label='Input: {:.4} {} at {:.1f} {}'.format(\n",
-    "              float(val_in), str(unit_in), wl_in.value, str(wl_in.unit)))\n",
+    "              float(value_in), str(unit_in), wavelength_in.value, str(wavelength_in.unit)))\n",
     "\n",
     "# Plot output\n",
-    "\n",
-    "plt.plot(wl_out.value, plot_flux_out.value,\n",
+    "plt.plot(wavelength_out.value, plot_flux_out.value,\n",
     "         marker='s', color=c_out, ls='none', \n",
     "         label='Output: {:.4} {} at {:.1f} {}'.format(\n",
-    "              float(val_out), str(unit_out), wl_out.value, str(wl_out.unit)))\n",
+    "              float(value_out), str(unit_out), wavelength_out.value, str(wavelength_out.unit)))\n",
     "\n",
     "# Set heights for dotted lines to markers as % of plot range\n",
-    "\n",
     "bottom, top = plt.ylim()\n",
     "yrange = top - bottom\n",
     "inheight = (plot_flux_in.value - bottom) / yrange\n",
     "outheight = (plot_flux_out.value - bottom) / yrange\n",
     "\n",
     "# Plot dotted lines to markers\n",
-    "\n",
-    "plt.axvline(wl_in.to(wl_unit).value, ymax=inheight, ls=':', c=c_in)\n",
-    "plt.axvline(wl_out.to(wl_unit).value, ymax=outheight, ls=':', c=c_out)\n",
+    "plt.axvline(wavelength_in.to(wavelength_unit).value, ymax=inheight, ls=':', c=c_in)\n",
+    "plt.axvline(wavelength_out.to(wavelength_unit).value, ymax=outheight, ls=':', c=c_out)\n",
     "\n",
     "# Miscellaneous\n",
-    "\n",
     "plt.ylabel('Flux ({})'.format(str(plot_unit)))\n",
-    "plt.xlabel('Wavelength ({})'.format(str(wl_unit)))\n",
+    "plt.xlabel('Wavelength ({})'.format(str(wavelength_unit)))\n",
     "plt.legend(fontsize='small')    \n",
     "plt.tight_layout()"
    ]
@@ -659,23 +627,19 @@
    "outputs": [],
    "source": [
     "# Input: 3631 Jy at 550. nm\n",
-    "\n",
-    "val_in   = 3631.      \n",
-    "unit_in  = u.Jy\n",
-    "wl_bp_in = 550.\n",
-    "\n",
-    "wl_unit  = u.nm\n",
+    "value_in = 3631.      \n",
+    "unit_in = u.Jy\n",
+    "waveband_in = 550.\n",
+    "wavelength_unit = u.nm\n",
     "\n",
     "# Output: Johnson V mag (AB)\n",
-    "\n",
-    "unit_out  = u.ABmag\n",
-    "wl_bp_out = 'Johnson, V'\n",
+    "unit_out = u.ABmag\n",
+    "waveband_out = 'Johnson, V'\n",
     "    \n",
     "# Spectrum: Flat power law in F_nu\n",
-    "\n",
     "pl_index = 0\n",
-    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wl_in, alpha=pl_index)\n",
-    "spec = SourceSpectrum(model)"
+    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wavelength_in, alpha=pl_index)\n",
+    "spectrum = SourceSpectrum(model)"
    ]
   },
   {
@@ -696,20 +660,16 @@
    "outputs": [],
    "source": [
     "# Input: 1.234e-8 flam at 500. nm\n",
-    "\n",
-    "val_in   = 1.234e-8    \n",
-    "unit_in  = su.FLAM\n",
-    "wl_bp_in = 500.\n",
-    "\n",
-    "wl_unit  = u.nm\n",
+    "value_in = 1.234e-8    \n",
+    "unit_in = su.FLAM\n",
+    "waveband_in = 500.\n",
+    "wavelength_unit = u.nm\n",
     "\n",
     "# Output: flam at 800. nm\n",
-    "\n",
-    "unit_out  = su.FLAM\n",
-    "wl_bp_out = 800.\n",
+    "unit_out = su.FLAM\n",
+    "waveband_out = 800.\n",
     "    \n",
     "# Spectrum: 5800 K blackbody\n",
-    "\n",
     "bb_temp = 5800 * u.K\n",
     "model = BlackBody1D(bb_temp)\n",
     "spec = SourceSpectrum(model)"
@@ -733,22 +693,19 @@
    "outputs": [],
    "source": [
     "# Input: 1.234e-21 fnu at 686. nm\n",
-    "\n",
-    "val_in   = 1.234e-21    \n",
-    "unit_in  = su.FNU\n",
-    "wl_bp_in = 686.\n",
-    "\n",
-    "wl_unit  = u.nm\n",
+    "value_in = 1.234e-21    \n",
+    "unit_in = su.FNU\n",
+    "waveband_in = 686.\n",
+    "wavelength_unit = u.nm\n",
     "\n",
     "# Output: photnu at 686. nm\n",
-    "\n",
-    "unit_out  = su.PHOTNU\n",
-    "wl_bp_out = 686.\n",
+    "unit_out = su.PHOTNU\n",
+    "waveband_out = 686.\n",
     "    \n",
     "# Spectrum: 5800 K blackbody\n",
     "bb_temp = 5800 * u.K\n",
     "model = BlackBody1D(bb_temp)\n",
-    "spec = SourceSpectrum(model)"
+    "spectrum = SourceSpectrum(model)"
    ]
   },
   {
@@ -769,25 +726,20 @@
    "outputs": [],
    "source": [
     "# Input: STmag = 12.240, F606W filter on WFC3 UVIS 2\n",
-    "\n",
-    "val_in   = 12.240      \n",
-    "unit_in  = u.STmag\n",
-    "wl_bp_in = 'wfc3, uvis2, f606w, mjd#59367'\n",
-    "\n",
-    "wl_unit  = u.nm\n",
+    "value_in = 12.240      \n",
+    "unit_in = u.STmag\n",
+    "waveband_in = 'wfc3, uvis2, f606w, mjd#59367'\n",
+    "wavelength_unit = u.nm\n",
     "\n",
     "# Output: Johnson V mag (AB)\n",
-    "\n",
-    "unit_out  = u.STmag\n",
-    "wl_bp_out = 'Johnson, V'\n",
+    "unit_out = u.STmag\n",
+    "waveband_out = 'Johnson, V'\n",
     "    \n",
     "# Spectrum: Flat power law in F_lambda\n",
-    "\n",
     "pl_index = 0\n",
-    "\n",
     "model = PowerLawFlux1D(amplitude=convert_flux(606 * u.nm, 1., su.FLAM), x_0=606 * u.nm, alpha=pl_index)\n",
     "spec = SourceSpectrum(model)\n",
-    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wl_in, alpha=pl_index)"
+    "model = PowerLawFlux1D(amplitude=flux_in, x_0=wavelength_in, alpha=pl_index)"
    ]
   },
   {
@@ -869,7 +821,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.10.6"
+   "version": "3.11.6"
   }
  },
  "nbformat": 4,
diff --git a/notebooks/WFC3/flux_conversion_tool/requirements.txt b/notebooks/WFC3/flux_conversion_tool/requirements.txt
index 2a8a2f707..74ad5e613 100644
--- a/notebooks/WFC3/flux_conversion_tool/requirements.txt
+++ b/notebooks/WFC3/flux_conversion_tool/requirements.txt
@@ -1,5 +1,5 @@
-astropy==5.2.1
-matplotlib==3.7.0
-numpy==1.23.4
+astropy
+matplotlib==3.8.3
+numpy==1.26.4
 stsynphot==1.2.0
 synphot==1.1.1