  We present a radio light curve of supernova (SN) 2014C taken with the
Arcminute Microkelvin Imager (AMI) Large Array at 15.7 GHz. Optical
observations presented by Milisavljevic et al. demonstrated that SN 2014C
metamorphosed from a stripped-envelope Type Ib SN into a strongly interacting
Type IIn SN within 1 year. The AMI light curve clearly shows two distinct radio
peaks, the second being a factor of 4 times more luminous than the first peak.
This double bump morphology indicates two distinct phases of mass-loss from the
progenitor star with the transition between density regimes occurring at
100-200 days. This reinforces the interpretation that SN 2014C exploded in a
low density region before encountering a dense Hydrogen-rich shell of
circumstellar material that was likely ejected by the progenitor prior to the
explosion. The AMI flux measurements of the first light curve bump are the only
reported observations taken within ~50 to ~125 days post-explosion, before the
blast-wave encountered the Hydrogen shell. Simplistic synchrotron
self-absorption (SSA) and free-free absorption (FFA) modelling suggest that
some physical properties of SN 2014C, such as the mass-loss rate, are
consistent with the properties of other Type Ibc and IIn SNe. However, our
single frequency data does not allow us to distinguish between these two
models, which implies they are likely too simplistic to describe the complex
environment surrounding this event. Lastly, we present the precise radio
location of SN 2014C obtained with eMERLIN, which will be useful for future
VLBI observations of the SN.
