Design of the ZC1 Mk-1. is generally credited to Percy
Collier and Bill Fever of Collier and Beale; a Wellington based radio design
and manufacturing company. It was as far as possible designed around
components readily available at the time, largely those used in the
manufacture of domestic radios. For the initial pre production trial
assembly run many components were sourced from the large spare parts stock
holdings of the New Zealand Post Office.
The special committee set up with representatives from the army, industry,
Ministry of Supply and the Post Office to oversee the specification, design,
procurement of components and the manufacture of the new radio was able to
report in April 1942 that sufficient materials were now available for the
manufacture of 750 sets of the 1000 Mk-1 sets approved. Considerable
difficulty was being experienced in obtaining certain components, especially
meters. The lack of meters forced a minor redesign so that only one
meter was required in production sets. The hole left in stocks of
already manufactured front panels was covered with a metal plate fitted with
a watch holder. In later production the watch holder was fitted
directly to the front panel.
The extreme difficulty in obtaining key components such
as meters, tuning capacitors and radio valves had caused lengthy delays in
accumulating sufficient sets of components to enable production to commence.
The ongoing delays in commencing manufacture was causing problems in
retaining skilled production staff as the Draft Board struggled to find
experienced qualified personnel to draft overseas to meet the growing demand
for skilled service personnel.
At least three versions of the Mk I are known.
- The first version, produced in small numbers, was fitted with an
aerial current meter. IF transformers with fixed cores and variable
capacitors were used.
- The second version, also produced in small numbers, used the same IF
transformers but had a plate with a watch holder fitted in place of the
aerial current meter.
- The third and most numerous version used different IF transformers
with fixed capacitance and variable cores. The watch holder is fitted
directly to the front panel without the need for a plate.
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
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.
Radio Corporation was given contracts
for the production of the ZC1 Mk I as was Radio
Ltd of Auckland.
The first issue of the ZC1 Mk I was in the Pacific at
Guadacanal and it saw active service for the first time when NZ troops
landed at Vella Lavella at 8am on the 18th of September 1943. Official
records indicate that it performed well in the dense and wet jungle out
performing many other types in use at the time. The Mk I also saw service on
Stirling Island where once again good results were achieved. The NZ 3rd
Division 2nd NZEF records show that they used the ZC1 in conjunction with
the American 48 set with good results. However given the relatively small
overlap of the frequency ranges of the two sets, the choice of working
frequencies must have been limited. Photo ZC1 Mk-1
in operation Nissan Island 1944.
Use was also made of the ZC1 for general
communications between the various support bases in New Caledonia.
Radio Mechanician servicing radio equipment in Noumea.
This is the only recorded active service seen by the ZC1 in WW2.