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.