PHILIPS L4Z65BT 'TRANSWORLD PORTABLE' (1957)

The Philips L4Z65BT was manufactured by Philips Electrical Industries of N.Z. Ltd in 1957.

Hybrid Valve / Transistor Portable Multiband Radio

In the crossover between valves and transistors some manufacturers found ways to combine both - for example Bell had the 34P7.  Philips produced this little gem, the Transworld Portable, which uses valves in the RF stages and uses solid state parts in the audio stages.

2 versions released - according to the schematics the MK1 was produced in 1957, and the MK2 the following year in 1958.

4-bands:
  517 - 1610 kc/s - BC
  1.6 - 4 mc/s - SW3
  5.9 - 12.1 mc/s - SW2
  12.1 - 22.1 mc/s - SW1

Batteries - 1 x 467 (67.5V), 8 x 950 (D-cell?)

Technical Information

Valves (3 valve, 1 diode, 3 transistors): DK96, DF96, DF96, OA85, OC71, ( OC72, OC72 ) Matched Output Pair

Intermediate Frequency: 452kc/s

Frequency Bands: 4

Chassis Notes(most schematics can be clicked to download a full size version)

1957 Philips L4Z65BT

1957 Philips L4Z65BT

1957 Philips L4Z65BT

1957 Philips L4Z65BT

1957 Philips L4Z65BT

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.