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It
is no secret that I have a soft spot in my heart for vintage electronic
equipment, particularly vacuum tube radios. Believe it or not, you can
even today buy a new radio with tubes†, but the tubes
will only be in the speaker driver circuit. The front-end tuner circuitry
will be solid state. That's OK, because you still get a "real" orange
glow from the tubes. If you really want a nostalgic experience, you
will need to procure an authentic vintage radio††.
Until about a decade ago, you used to be able to jokingly say that
you have a computer or a television that still uses vacuum tube technology.
Now that there are virtually no CRT (cathode ray tube) computer monitors
or TV screens in service (in 1st-world countries, anyway), you can't
get away with it. Bummer. I suppose someday when holographic or direct
neural imaging is commonplace, late-adopter types (like me) will joke
about our computers and TVs still having physical displays. On
of the few remaining realms for vacuum tubes is high power transmitters
used in radio and television broadcasting. It is evidently still cheaper
and easier to build a tube for some applications than series/paralleling
massive groups of solid state devices, particularly at frequencies well
below a gigahertz.
Alpha
Tubes (RF Concepts) runs a nice full-page advertisement in the ARRL's
QST magazine with a line of vacuum tubes that remind me of some of the
ones I photographed from the
Microwave Museum display at the 2009 International Microwave Symposium
(IMS, or MTT-S) show in Boston. The page is reproduced below without
bothering to get permission since they will probably not object to the
free exposure (tell them you saw it here on RF
Cafe, please). If you want to see some old radio equipment up
close and personal, find an amateur radio swap meet in your area.
Alpha Tubes Advertisement from the September
2013 Edition of QST
† See
my "Tesslor
Model R601S Vacuum Tube AM/FM Radio Teardown Report"
†† See my "1941
Crosley 03CB Floor Console Radio Restoration Project"
Posted September 9, 2013 |
