90 Baby Grand Middle

Philco, Philadelphia Stg. Batt. Co.; USA

Data
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  • Year
  • 1931
perfect model
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 18816

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Number of Tubes
  • 9
  • Main principle
  • Superhet with RF-stage; ZF/IF 175 kHz
  • Tuned circuits
  • 7 AM circuit(s)
  • Wave bands
  • Broadcast only (MW).
  • Power type and voltage
  • Alternating Current supply (AC) / 50 to 60 cycles, 115 Volt
  • Loudspeaker
  • Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: 90 Baby Grand [Middle] - Philco, Philadelphia Stg. Batt
  • Shape
  • Table-Cathedral-Type (upright, round top or gothic arch, not rounded edges only).
  • Dimensions (WHD)
  • 0 x 18 x 0 inch / 0 x 457 x 0 mm
  • Notes

  • Models 90 and 90A were available in a cathedral, a lowboy, and a highboy cabinet. The chassis was made in three versions - an early model 90 and 90A with two 45 output tubes in push-pull, a middle version with one 47 output tube, and a late version with two 47 output tubes. Model 90 is for 115 VAC 50-60 Hz; model 90A is for 115 VAC 25-60 Hz.

    The models 90 and 90A "early" and "middle" have a 4-gang tuning condenser plus 3 tuned IF circuit - both with IF 175 (Rider's change note 8-3). The version "middle", which are above serial number 237,001, of the model 90 and 90A has tubes: 24 RF, 27 osc, 24 1st det., 24 IF, 27 2nd det. rect., 27 det. amp., 27 1st AF amp, 47 output and 80 rectifier. The "late" model 90 and 90A again have push-pull output but with 2 x 47 tubes. See Rider's Philco 3-35 for IF 260 kHz. Applied on models serial B-32001 to B-35000 and above B-53100. They have a 3-gang tuning condenser and only 6 tuned circuits. The same differences can be found for all cabinets, both 90 and 90A: Baby Grand (Cathedral), Lowboy and Highboy (with a stretcher).

    The cathedral cabinet is the classic design by Edward L. Coombs, and is similar to the cathedral versions of model 21, 35, 46, and 70. [3331438-1133]

  • Price in first year of sale
  • 69.00 $
  • External source of data
  • E. Erb 3-907007-36-0
  • Circuit diagram reference
  • Die «Thali Schemasammlung» führt das Modell.
  • Literature/Schematics (3)
  • Philco Folder 2674.

 Collections | Museums | Literature

Collections

The model 90 is part of the collections of the following members.

 Forum

Forum contributions about this model: Philco, Philadelphia: 90 Baby Grand

Threads: 2 | Posts: 8

What does the open circle and filled in square mean on a scematic? See attached

The radio I'm working on (Philco Model 90 Middle) has two capacitors on each leg of the incoming AC power going to ground. Are they necessary? It seems to me to be an accident waiting to happen. See attached

Attachments

James Hochstetler, 05.Jan.22

Weitere Posts (4) zu diesem Thema.

First of all I'm a beginner to radio restoration. My question is on the capacitors packed inside the two metal containers 24 and 30. 24 says it has 4 capacitors inside but only has 3 leads exiting the container. 30 say it has two capacitors inside but has 3 leads exiting the container. On the schematic it shows 24, 4 (four) times but no values listed. 30 shows up twice but again no value. The values are different on all 6 capacitors so how do I know which one goes where? Am I missing something? One more question on polarity of the two electrolytics, 56 and 57. The schematic does not indicate polarity. My intuition says + for 56 goes to the choke 55. On 57, negative generally goes to ground. Any thoughts or help would be appreciated.

P.S. Am I the only one that doesn't like codes inside a circle rather than the actual value?

James Hochstetler, 01.Dec.21

Weitere Posts (4) zu diesem Thema.