2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/130330We show that a single-Cooper-pair transistor (SCPT) electrometer emits narrow-band microwave radiation when biased in its sub-gap region. Photo activation of quasiparticle tunneling in a nearby SCPT is used to spectroscopically detect this radiation, in a configuration that closely mimics a qubit-electrometer integrated circuit. We identify emission lines due to Josephson radiation and radiative transport processes in the electrometer, and argue that a dissipative superconducting electrometer can severely disrupt the system it attempts to measure.4 pages, 3 figuresMesoscale and Nanoscale PhysicsSuperconductivitytext