PHILIPS L4Z65BT 'TRANSWORLD PORTABLE' (1957)

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

Other radios based on the same chassis:

Hybrid Valve / Transistor Battery-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 Twon and Country 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?)

1957 Philips L4Z65BT 'Transworld Portable'
Radio and Electrical Review, February 1958

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:

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.

Philips model codes are complex - they are explained in-depth on the Philips brand page. 

Mullard codes: The model codes from Mullard sets (unlike their Philips counterparts) appear to contain valve count and date information.  For example, the model 525 is a 5-valve 1945 design.  The 2 appears to just be an identifier (most likely in case there were two models in 1945 with 5 valves, which there was - the 515 is the small 'Meteor' mantle set).

Fleetwood codes are often just a rearranged version of the Philips code.  For example, the FL374T transistor radio is a rearrangement of the Philips model L3Z74T.  Early Fleetwood codes were numeric with F on the end.  From about 1959 onwards the codes were much more like their Philips counterparts.  They start with F or FL (or sometimes FZ for larger consoles)...  These later codes also tend to end in a Philips-style identifier for the power source (A for mains, B for battery, T for transistor battery, etc - see the Philips brand page for more info on that).

Other documented models using this chassis (2 in total)

YEARMODEL NAME
1957 Fleetwood 465F 'Rambler'