Zenith Trans-Oceanic Model B600

  • Batteries: Zenith Z-985 (Combined 90V HT & 9V LT - rated for 150 hours service) plus 1.5V cell (Type Z1) for dial light
  • Mains: 110-125V AC/DC 25-60Hz
    • Ballast adaptor available as an optional extra for 220V operation
  • Wavebands: 7 switchable bands giving the following coverage:
    • Standard Broadcast: 540 - 1600KHz
    • Weather Band: 4.0 - 9.0MHz
    • Weather Band: 2.0 - 4.0MHZ
    • 16m Band: 17.40 - 18.20MHz
    • 19m Band: 14.80 - 15.60MHz
    • 25m Band: 11.40 - 12.20MHz
    • 31m Band: 9.30 - 9.90MHz
  • Valve lineup: 6 total
    • 1U4 (x2, RF & IF amplifiers)
    • 1L6 (Converter)
    • 1U5 (Detector/AVC/1st audio)
    • 3V4 (Audio output)
    • 50A1 (Current regulator)
  • Released: May 1959, cost $140
  • Physical size: 17" x 8" x 11" (approx.), weighs 17lbs w/o battery
The immediate difference between the 600 series of T/O and its predecessor, the H500, is the use of the 'slide-rule' type dial. This greatly improves ease of tuning and scale readability. It was further improved by the addition of a dial light (controlled by a spring-loaded slide switch on the front panel).

A spring loaded take up reel made for easy and efficient power cord storage and the new models saw the re-introduction of the log book, charts and 'Dial-o-Map' (protected by their own cover) which had last been seen on the 1949 8G005Y.
'Under the hood', the 600 series had further electronic improvements - most notably the use of a current regulator tube to ensure that AC line voltage fluctuations did not affect the set's operation. This was important as the oscillator tubes were being pushed to their design limits.

Additionally, the 'Wavemagnet' antenna was smaller and lighter - it now used ferrite rod technology instead of being a coiled wire.

The 600 series of the Trans-Oceanic was first introduced in May 1954. In all, there were six 'versions' (in fact, identical) offered between then and 1962, when the tube T/O was finally replaced. These versions were, in order, the L600, R600, T600, Y600, A600 and, from 1959 to 1962, the B600. The B600 is believed to be the very last American-made tube portable radio.
It is reckoned that c.270,000 T/O's of the 600 series were produced - compared to c.245,000 for the H500, c.90,000 for the G500 and c.110,000 for the early 8G005Y.

Last updated 2nd June 2008