Philco Model 47-1227 Radio and Phonograph Console (1947)
|"Glorious reproduction of radio and recorded
music! No needles to change! Featherweight
Tone Arm saves record wear. Concert Grand
Dynamic Speaker for fine tone and
performance! Smart walnut tilt-front cabinet"
The Philco 47-1227 is a very solid performing
9-tube radio-phonograph providing coverage
of both the standard broadcast (540-1720kc)
and modern FM (88-108mc) bands. It has
excellent sensitivity and selectivity, owing to the
use of double IF stages plus, for the FM band,
a high gain pentode RF amplifier. The set uses
a 12" electrodynamic speaker mounted to the
front-panel that tilts out to reveal the internal
phonograph. Negative feedback is applied from
the secondary of the output transformer
through to the input of the af stage, providing
improved frequency response and reduced
harmonic distortion. This model was introduced
in 1947 with an initial sales price of $239.50.
The 47-1227's tube line-up is 6K6GT*2
(push-pull power amp), 6AG5 (FM rf amp), 7F8
(converter/osc), 6BA6 (1st IF), 7R7 (2nd IF, AM
det, AVC det), 7X7 (ratio detector, 1st AF),
6J5GT (phase inverter), 5AZ4 rectifier.
Interestingly, this radio does not use Philco's
notorious FM1000 discriminator, which was a
forerunner of today's PLL discriminators for
FM. Instead it uses a ratio detector based upon
the dual diode section of the 7X7 tube. There is
no AFC on the radio and drift is a problem on
the FM band while it is warming up.
Of all the radios in my collection, this is one of
the best performing (at least on BC). It used to
sit in our great room where it would often get
played while we were eating dinner. It sounds
just great tuned to WJIB (on BC) out of
Cambridge (about 15 miles away), even after
dusk when they shut the radiated power down
to 5W! Some of my other radios will barely pick
it up then.
I found this set at a yard sale and when I tested
it out I could hear static but it would not tune in
any stations. It turned out the screen-grid
decoupling capacitor for the 6BA6 1st IF tube
was shorted to ground. After this diagnosis I
gave it a complete re-cap, though it wasn't the
easiest chassis I've ever worked on owing to its
use of a sub-chassis that's very cramped. The
phono does work but it needs a replacement
...brings you static free FM broadcasts and standard programs.
Automatic record changer plays up to 12 records.
Permanent needle lasts for thousands of plays!