This RCC sourced with one AA cell was used by me for a long time, one day the light in it didn't work anymore.
The resistance was 3 Ω and it was lighting after it's taking out sourcing with 70 mA from the 1.5V.
Problem was the LIGHT switch on the top, I have used a contact cleaner and it was then OK.
The capacitance in the input circuit is 6800 pF. For 77.5 kHz the inductance should be 630µH.
The IC is TFK U2775B.