Philco Model 18B (18) Baby Grand Cathedral Radio (1933)
Philco 18B Baby Grand
The Philco Model 18 Baby Grand (18B) debuted in July of 1933.
It had an initial sales price of $60 and in keeping with one of
Philco's catch-phrases of the day, "
there is a Philco for every purse
and every purpose"
, it was one of no less than 8 new all-electric
Baby Grand models offered for the 1934 season, ranging in
price from $27.50 to $75. However, perhaps because of Philco's
marketing policy, with the brunt of their Baby Grand advertising
focused on the lower cost Junior models and the top-of-the line
16B, it was not a big seller and fewer than 13,000* were sold. As
a result, it's relatively uncommon today and has become highly
collectible.                                                       (*
src: philcoradio.com)

The 18B is an excellent receiver with an impressive feature list,
including:-
I found this radio in a large antiques store in Southern
Maine and as I was inspecting it, I saw that it  had two
line cords attached, each with a two-pronged standard
ac-line plug. Upon looking closer, I noticed that one of
these was wired between the antenna and ground. I
feared the worst, feeling certain that someone would
have plugged the incorrect cord in at some time or
another while attempting to try out the radio. This feeling
wasn't helped by the assistant in the store asking me if I
wished to do just that! I declined the invitation, but
because of its rarity, I bought the radio anyway. Upon
getting it home and investigating, I discovered that the
antenna coil was blackened with soot. Yes, someone
scroll down for more..
Model 18B chassis view
                                                      Philco Offers Many Cabinets for Selection

The largest manufacturer of radios in the world has always offered a variety of cabinets on each chassis they make, but this
year the popularity of its new 16 series has prompted Philco to offer the option of as many as five different types of cabinets
on the popular series.

In all these models the same 18 chassis is used which means that four-point bass compensating tone control, shadow tuning and
automatic-volume-control is included, whether the purchaser selects one of the Inclined Sounding Board models or the more
compact Baby Grand.

The leader in the 18 series, as is invariably the case with Philco, is the 18X model, in which the patented inclined sounding board,
oversize electrodynamic speaker, and exclusive Philco super "class A" audio system assure pure and undistorted reproduction of
any program, whether at a whisper or loud enough to fill an auditorium.

Two highboys are also featured in the 18 series-one with doors and one without. A lowboy of extremely popular design and
moderately priced is the fourth version of the 18 series, while the baby grand provides the ideal radio for the smaller living
room where space is at a premium.

In addition to covering the complete broadcast band, all of the 18 series will receive police, airplane and amateur
communications and this feature has greatly added to their popularity with radio listeners who desire more variety to their
entertainment than that provided by the regular broadcasting stations."
...attractive baby grand which offers a score of new improvements.
Like the top-of-the-line model 16B, the 18B features a Class A
output stage using triode connected push-pull 42s and a type
42 driver. Frequency coverage is from 520-1500kc (standard
broadcast) and 1.5-4.0mc (short wave). The 8 tube line-up is 78
(RF), 6A7 (LO & mixer), 78 (IF), 75 (det/AVC/1st AF), 42
(driver), 42*2 (power amp) and 80 (rectifier).
  • Super "Class A" Audio System
  • 8-tube superheterodyne circuit
  • Bass Compensating 4-point Tone Control
  • Automatic Volume Control
  • Police and Aeroplane calls
  • Shadowmeter Tuning
  • Beautiful hand-rubbed cabinet of Black Walnut
    and Oriental Wood
The model 18 receivers used a new state-of-the-art 8-tube superheterodyne chassis that was one of the first Philco designs to adopt the new
6A7 pentagrid converter tube as mixer and local-oscillator (LO). Prior to this, to keep the tube count down Philco had no option but to use the
inferior single-tube autodyne circuit in their economy sets, such as the
51B and even the recent 19B. This could not accommodate AVC and
the arrangement was unreliable, often ceasing oscillation if components were slightly out of tolerance. Higher tube count models avoided
these and other issues by using separate mixer and LO tubes, and many, especially the all-wave ones, would continue to do so, but the
pentagrid circuit represented a genuine advance, particularly  for the intermediate and junior models. In addition to the 6A7, the 18B also used
the new type 78 variable-mu pentode for RF and IF amplification as well as the recently introduced 75 for the combined functions of 2nd
detector, AVC generation and first AF amplifier. With the adoption of these multi-function types, Philco set designers were now able to provide
improved audio, such as super class-A push-pull, and yet still keep the tube count down and offer the set at an affordable price.

With these 1934 models, all the basic elements of the economical superheterodyne were now in place and it can truly be said that the circuit
had "come of age". Tube types would come and go, but the basic configuration would now remain intact right through the end of the tube era.
had likely plugged in the incorrect
cord! Luckily, however, though
burned, one small accessible piece
of the coil had fused and when
repaired the coil showed the correct
resistance and I was able to
complete the restoration. Although
the radio now plays, rewinding that coil is on my to-do
list for sometime soon. Note: Ron Ramirez, at
philcoradio.com offers a coil rewinding service for early
Philcos.
Blackened antenna coil
The following article was clipped from a newspaper dated March 4th 1934. The reference to model 16 in the first paragraph is
curious and perhaps is a misprint - it would make more sense for it to read "new 18 series...". The reference to 5 models also
appears to overlook the existence of the model 18RX chaiside with remote speaker, referred to by
philcoradio.com.
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