Key components such as meters, valves and the main tuning capacitors were all of Australian, American or English manufacture. Shortage of these components was to plague production until the later part of the war when American "Lend Lease" components became available. Official NZ war records show considerable frustration over shipping problems with large quantities of urgently needed, and already paid for, components being held up for many months on the wharves in the USA while officials argued over their shipping priority.
In all, it is now believed that approximately 5,000 ZC1 Mk I sets were made. However manufacture of the Mk I was barely commenced before design and production of the Mk II was already being planned.
Wellington based Radio Corporation was given contracts for the production of the ZC1 Mk I as was Radio Ltd of Auckland.