90 Baby Grand Middle
- United States of America (USA)
- Manufacturer / Brand
- Philco, Philadelphia Stg. Batt. Co.; USA
- Broadcast Receiver - or past WW2 Tuner
- Radiomuseum.org ID
Click on the schematic thumbnail to request the schematic as a free document.
- Number of Tubes
- 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
- Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
- Wooden case
- from Radiomuseum.org
- Model: 90 Baby Grand [Middle] - Philco, Philadelphia Stg. Batt
- 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
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.
- Mentioned in
- Philco Radio 1928-1942
- Literature/Schematics (1)
- Rider's Perpetual, Volume 2 = 1932 and before (Philco 1928-36 Wiring Diagrams, Parts Lists, and Essential Service Data)
- Literature/Schematics (3)
- Philco Folder 2674.
- Other Models
Here you find 3845 models, 2145 with images and 3233 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Philco, Philadelphia Stg. Batt. Co.; USA
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
James Hochstetler, 05.Jan.22
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