waveguide filters
... that waveguide filters used in multiplexers originally needed decoupling resonators for each input, but these were found to be unnecessary by E. J. Curly when he accidentally mistuned a diplexer?
... that <b id="mwDoI"><a href="./Waveguide_filter" id="mwDoM" rel="mw:WikiLink" title="Waveguide filter">waveguide filters</a></b> <i id="mwDoQ">(example pictured)</i> used in <a href="./Multiplexer" id="mwDoU" rel="mw:WikiLink" title="Multiplexer">multiplexers</a> originally needed <a href="./Decoupling_(electronics)" id="mwDoY" rel="mw:WikiLink" title="Decoupling (electronics)">decoupling</a> <a href="./Resonator" id="mwDoc" rel="mw:WikiLink" title="Resonator">resonators</a> for each input, but these were found to be unnecessary by E. J. Curly when he accidentally <a class="mw-redirect" href="./Tuned_filter" id="mwDog" rel="mw:WikiLink" title="Tuned filter">mistuned</a> a <a href="./Diplexer" id="mwDok" rel="mw:WikiLink" title="Diplexer">diplexer</a>?