LH Zenette Ch= 2022

Zenith Radio Corp.; Chicago, IL

  • Year
  • 1931/1932
  • Category
  • Broadcast Receiver - or past WW2 Tuner
  • Radiomuseum.org ID
  • 18990
    • alternative name: Chicago Radio Lab

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

 Technical Specifications

  • Number of Tubes
  • 7
  • 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) / 115 Volt
  • Loudspeaker
  • Electro Magnetic Dynamic LS (moving-coil with field excitation coil)
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: LH Zenette Ch= 2022 - Zenith Radio Corp.; Chicago,
  • Shape
  • Table-Cathedral-Type (upright, round top or gothic arch, not rounded edges only).
  • Notes
  • [3331454B] This model LH Zenette with chassis 2022 has an unusual 4-gang variable condenser but only 3 IF cirquits - in total 7 tuned circuits. There are also export models with other mans transformers.
  • Price in first year of sale
  • 50.00 $
  • External source of data
  • E. Erb 3-907007-36-0
  • Circuit diagram reference
  • Rider's Perpetual, Volume 2 = 1932 (Models 1931/1932)
  • Literature/Schematics (1)
  • Thali schematics, Switzerland Zenith page 5

 Collections | Museums | Literature

Collections

The model LH Zenette is part of the collections of the following members.

 Forum

Forum contributions about this model: Zenith Radio Corp.;: LH Zenette Ch= 2022

Threads: 1 | Posts: 1

Repair of the Zenette LH transformer.

 

In my opinion the voltage change from 110 to 220 V, many years ago, seemed the end of life for this radio. To prevent such a mistake a second time I constructed the new transformer ready for the 235 V mains.

The pictures below nearly tell the whole story. The high voltage secondary was damaged by a short circuit. Counting the windings at disassembly shows 4 turns/volt. For comfort two flanges were added.

 

The transformer was rebuilt as follows:

§         High voltage secondary 2760 turns with center tab, dia 0.15 mm  (2 x 345 V)

§         Paper

§         Copper screen from the original transformer. Electrical tape is used to prevent the copper foil to act as a short circuit winding.

§         Paper

§         Primary 940 turns, dia 0.35 mm (235 V)

§         Paper

§         5 volt secondary, 20 turns, dia 1.1 mm

§         Electrical tape for insulation and to fix the wire.

§         2.5 volt secondary, 10 turns with center tab, 2.5 mm2 multicore wire. The center tab is connected with a 0.5 mm2 wire.

§         Electrical tape

 

All wire is renewed. Backing paper was used for separation between all layers. The width of the paper is a bit larger than the inner distance between the flanges to ensure good insulation at the outside. Because the original thick 2.5 volt wire was in bad condition I replaced it with 2.5 mm2 multicore wire. This wire has the advantage being very flexible. Winding is done with a 12V-drilling machine. A foot switch applies the 12V power.

Eduard Hontele, 07.May.08

Weitere Posts (1) zu diesem Thema.