Portable 56

Ever Ready Co. (GB) Ltd.; London

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  • Year
  • 1936 ??
  • Category
  • Power supply/conditioner or battery or charger 
  • Radiomuseum.org ID
  • 238638

 Technical Specifications

  • Wave bands
  • - without
  • Power type and voltage
  • Is a battery or storage battery / 10.5 & 136.5 Volt
  • Loudspeaker
  • - - No sound reproduction output.
  • from Radiomuseum.org
  • Model: Portable 56 - Ever Ready Co. GB Ltd.; London
  • Dimensions (WHD)
  • 145 x 273 x 76 mm / 5.7 x 10.7 x 3 inch
  • Notes

  • Uses 91 off "B" cells arranged 7 x 13 layout. One tap at +10.5V. Used in McMichael 484 and others. The tap is at +10.5V, so this point goes to Chassis/LT- if the Grid Bias is required, the actual HT is then 126V. Size is estimated from known Ever Ready packs and size of U10 / "B" size cell.

    On the "Winner" and "Portable" series the low voltage is a GB (Grid Bias) tap, not an actual LT (Low Tension filament) cell(s). Though some used with "All Dry" sets from 1939 (e.g. Portable 61) the LT would usually have been rechargeable Lead Acid 2V cell (accumulator)

    Connection is by a socket at three corners and flying leads with 1/8th inch wander plugs for + and - or various taps. None of this series use layer cells / "Biscuits", all use separate cells with connection wiring (Usually "B" Size = Ever Ready U10).

  • Author
  • Model page created by Michael Watterson. See "Data change" for further contributors.

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The model Portable 56 is part of the collections of the following members.

 Forum

Forum contributions about this model: Ever Ready Co. GB: Portable 56

Threads: 1 | Posts: 1

The most economical solution is likely 1off  6 way  AA cell holder in series with single AA holder (or an 8 way holder with one cell position bypassed) for - to +10.5V tap and then 10 off  8 way AA Holder + 1 x 4 way (about 1 Euro each inc postage from China) for the additional 126V. There is ample space. 

Alkaline AA can have up to 8 years shelf life and are slightly higher capacity than the original Zinc Carbon "B" cells. Zinc Carbon or Zinc Chloride "AA" cells may have  about 18 months shelf life or less, more prone to leak and also about 1/2 capacity of original "B" Cells.  Even alkaline PP3 cells are about 1/4 capacity or even 1/5th, cost more  and don't provide a 10.5V tap. Typically I get 10 to 12  Zinc Carbon AA cells for 2 Euro and 8 off Alkaline AA for about 2.50 Euro. The Alkaline cells (even a cheap brand) should last over 250 hours and maybe 300 hours assumimg a nominal 10mA HT current. Between about 1928 (Oxide Direct Filaments) and "the end" about 1961 of battery Valve/Tube radios the HT consumption of AM only sets is between 6mA (45V personal models) to 12mA (some table models). Much less change than the LT which over the same time may be 600mA @ 2V down to 125mA @ 1.4V nominal

The carton should be a top part with five labels printed on 80 or 90gm quality paper and stuck on it with paper glue (Pritt/UHU Stick) made from heavy card (180 to 200gm). The bottom part can be blank as the battery pack base was often blank and made from folded Pizza carton style card or plastic corrugated card for strength. It needs smaller dimensions to allow for thickness of top part of box and its own wall thickness.

Two thin wooden/ plywood/ MDF battens can run along the long sides with three sockets screwed/riveted on made of cut up coffee or other tinned steel. 

 

Michael Watterson, 02.Nov.13

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