The transmitter oscillators were condenser-tuned and so frequency stability was not high until quartz crystal control was implemented in 1933.
2.
Unlike other drift-reducing techniques ( such as crystal control or frequency synthesis ), the Wadley Loop does not attempt to stabilize the oscillator.
3.
These included a 400'external capacity non-reflex camera with improved ergonomics over the CM-77 and which retained the 115 volt ac powering requirement, and a 400'external capacity reflex camera which incorporated a dc motor and crystal control, possibly intended to compete with the Cinema Products CP-16R . Neither of these developmental models got beyond the pre-production stage of development.
मोबाइल