Hikers One Octal

Ensign Radio, The Electric Lamphouse Ltd.; Wellington

Dati
Forum
Immagini
Collezioni

  • Anno
  • 1945 ?
  • Categoria
  • Kit, scatola di montaggio (parti sfuse e istruzioni o solo istruzioni di montaggio) 
  • Radiomuseum.org ID
  • 355222

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 Specifiche tecniche

  • Numero di tubi
  • 1
  • Gamme d'onda
  • Solo onde medie (OM).
  • Tensioni di funzionamento
  • Batterie a secco / 9 & 1.5 Volt
  • Altoparlante
  • - Per cuffie o amplificatori esterni
  • Materiali
  • Vari materiali
  • Radiomuseum.org
  • Modello: Hikers One Octal - Ensign Radio, The Electric
  • Forma
  • Diverse forme (descritte nelle note).
  • Annotazioni

  • Octal Hikers One

    The Hikers One has been a wonderfully popular set and there is no doubt that the circuit has much to commend it. The principal features of the original circuit are the use of a 1.5-volt cell for the filament of the valve and a 9-volt battery for the B supply. Equally important are the low filament current of the 49 (about 50 milliamperes at 1.5 volts) and the method of reaction control which does not interfere with operating voltages and thus maintains the effective amplification of the valve. However, a little serious thinking will show that the actual set can be improved. For instance, what about the coil? If it is considered necessary to use a large coil of heavy wire for a crystal detector, why not use the same method with a valve detector for highest efficiency? 

    DETECTOR VALVE. In order to select a high-efficiency valve for the function of detector, the charts for battery valves were carefully scrutinised and it was decided that type 1Q5G was outstanding. This tube is a beam-power amplifier and has the remarkable transconductance rating of 2,100 with 90 volts on plate and screen. Next in order of merit comes type 1C5G with a transconductance of 1,500. Both tubes performed well in the completed receiver. Type 33 may be expected to give equivalent performance to the 1C5G but the filament current at 1.5 volts is about 200 milliamps, as compared with tubes 100 milliamps, for each of the other two tubes. Each of the three tubes has high transconductance which means that small signal voltages applied to the control grid cause large variations in plate current, which is the desired effect in grid leak detectors. Other tubes which may be used are types 1J5G and 1A5G which will provide performance about equivalent to that of type 49 which may be used in the same circuit. The four 1.4 volt tubes 1Q5G. 1C5G, 1J5G, and 1A5G all have the same socket connections and are directly interchangeable, the first two requiring fewer turns for the reaction winding. Each of these should have a one-ohm resistor in the filament lead to reduce the voltage of the cell to 1.4 volts. The screen and grid connections in this set should be carefully noted and made exactly as shown in the wiring diagram. 

  • Bibliografia
  • -- Original-techn. papers. (Lamphouse Annual 1945-46 Pages 77, 78 & 82)
  • Autore
  • Modello inviato da Brian Stevens. Utilizzare "Proponi modifica" per inviare ulteriori dati.

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