and I laugh every time I see a 6L6 tube.
This type, however, was the first of the pentode beam power tubes, used in the very first (true) hi-fidelity amplifers for home entertainment units.
The first of these?
Magnavox AMP-101, circa 1948.
Together with its companion AM-FM-Shortwave tuner, these were priced at $1400...in 1948.
Magnavox was first in many areas...the hi-fi loudspeaker, for example.
In fact, loudspeakers in general, all used the early Magnavox patents.
Just as radio receivers of the superhetodyne variety, all used RCA patents.
FM receivers, Hazeltine and Armstrong early patents...likewise.
The Collins 618T-x HF transceiver, 400w PEP, built from about 1962-78, was universally equipped in overwater airliners and military. It had tube finals, 4CX250A(?), and remained in service for many more years.
Used one of these just last night to communicate with Khartoum.
Worked to perfection.
