The Philips 666A was manufactured by Philips Electrical Industries of N.Z. Ltd in 1935.
6-valve dual-wave radio, one of the earlier Philips NZ sets, made by Radio Corp. NZ
Typically seen in the cabinet photographed above, but there may have been some released in a more standard tombstone cabinet as seen below (this was one of the earliest references in media to this new model)
Advertising from later in 1935 refers to this model as the 'Pylon'
There is a later version with 4 controls on the front, the model 666D
NZ Herald, 9 Feb 1935
Manawatu Times, 19 March 1935
The Press, 4 May 1935
NELSON EVENING MAIL 12 SEPTEMBER 1935
Intermediate Frequency: 256kc/s or 285kc/s
Frequency Bands: 2
Chassis Notes(most schematics can be clicked to download a full size version)
The original IF for the 666 was 265kc/s, however due to Christchurch and Dunedin stations causing beat problems with this frequency it was boosted to 285kc/s on some sets. There is no known list of serial numbers vs. IF's so some experimentation will be required to determine which IF's your set has. See the service information above for further details on how to check.
General Construction Notes for Philips Electrical Industries of N.Z. Ltd:
Model codes are explained on the Philips brand page. Philips early-mid century were probably the Google of their time - they had branches in many countries and a global brand that everyone knew - and were apparently happy to let engineers come up with new ideas and implement them. Construction is often overly complex but very well engineered - although repairs can also take a complex path. They used time-in-motion studies to find the most cost effective way to asemble sets and sometimes this means repairs can be nightmarish (if you've ever worked on a V7A Theaterette this will be all too aparent). U suffix model numbers are transformerless (hot chassis) sets and great care should be taken, or the sets avoided altogether.