• Country
• United States of America (USA)

• Manufacturer / Brand
• Hammarlund Mfg. Co. Inc.; New York, NY

• Year
• 1947 ??

• Category
• Commercial Receiver (may include amateur bands)

• Radiomuseum.org ID
• 44072

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

• Number of Tubes
• 16

• Valves / Tubes
• 6K7 6K7 6L7 6J7 6K7 6SK7 6SK7 6H6 6N7 6SJ7 6SK7 6H6 6J5 6F6 6F6 6F6

• Main principle
• Superhet with RF-stage

• Wave bands
• Broadcast plus more than 2 Short Wave bands.

• Power type and voltage
• Line / Storage batteries (perhaps also batteries) / AC: 105; 115; 125 / DC: 5 x 45 & -45 & 6 Volt

• Loudspeaker
• - This model requires external speaker(s).

• Material
• Metal case

• from Radiomuseum.org
• Model: Super Pro SP-400-SX - Hammarlund Mfg. Co. Inc.; New

• Shape
• Boatanchor (heavy military or commercial set >20 kg).

• Dimensions (WHD)
• 546 x 0 x 387 mm / 21.5 x 0 x 15.2 inch

• Notes

• = SP-400X with special tuning range 1.25 - 40 MHz.

  AM / CW receiver with frequencies from 1.25 to 40 MHz divided into 5 ranges:
  A: From 1250 kHz to 2500 kHz
  B: From 2500 kHz to 5000 kHz
  C: From 5 to 10 MHz
  D: From 10 to 20 MHz
  E: From 20 to 40 MHz
  The tuning scale (Band spread dial) has 100 divisions, each of which has a different calibration according to which of the 5 ranges is selected:
  A: 20 kHz / division
  B: 50 kHz / division
  C: 100 kHz / division
  D: 100 kHz / division
  E: 500 kHz / division

  The external power supply works with a 5U4G tube which supplies + 380 V DC for the final power audio stage, +250 V DC for all other tubes and +100 V DC for the screen grids, plus 6.3 V AC for the filaments. An additional 5Y3GT tube supplies a voltage of -50 V DC for some negative bias.
  
  For use with batteries: 5 x 45 V "B" batteries drain 117 mA at 225 V and 4.5 mA at 90 V;  , 1 x 45V "C" battery drain 10 mA and 1 x 6V storage battery drain 6.25 A for heaters.
  
  The impedance for the external speaker is 500 Ω.
  Input for phono and jack for headphones. Inserting the headphone does not exclude the loudspeaker. S meter.

• Net weight (2.2 lb = 1 kg)
• 43 kg / 94 lb 11.4 oz (94.714 lb)

• Price in first year of sale
• 360.00 $

• External source of data
• Ernst Erb

• Circuit diagram reference
• Rider's Perpetual, Volume 15 = 1947 and before

• Mentioned in
• “Radio Rivista” official organ of "ARI Amateur Radio Association" of Italy, number 1, January 19

• Other Models

• Here you find 144 models, 92 with images and 58 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
  All listed radios etc. from Hammarlund Mfg. Co. Inc.; New York, NY