828

Motorola; London

Data
Forum
Pictures
Collections

  • Year
  • 1965 ?
  • Category
  • Car Radio, perhaps also + sound player/recorder
  • Radiomuseum.org ID
  • 176271
    • alternative name: Motorola Automotive
    • Brand: World Radio

 Technical Specifications

  • Number of Transistors
  • 7
  • Main principle
  • Superhet with RF-stage
  • Wave bands
  • Broadcast (MW) and Long Wave.
  • Power type and voltage
  • Storage Battery for all (e.g. for car radios and amateur radios) / 12 Volt
  • Loudspeaker
  • - This model requires external speaker(s).
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: 828 - Motorola; London
  • Shape
  • Chassis only or for «building in»
  • Notes
  • Similar to model 727 except for Push-Pull audio output stage. Chassis similar to model 818T.
  • Author
  • Model page created by Keith Staines. See "Data change" for further contributors.

 Collections | Museums | Literature

Collections

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

 Forum

Forum contributions about this model: Motorola; London: 828

Threads: 2 | Posts: 3

The pictures I have uploaded were taken by me during the repair of a Motorola 828.  All three AF117 transistors, which are known to suffer internal faults commonly referred to as the 'tin whisker' problem, resulting in leaks or short-circuits between, e.g., the collector and screen, have been replaced with more modern equivalents.  I have also replaced the by now 50 year old electrolytic capacitors with modern types, using the nearest available capacitance values and working voltages wherever possible, althout the  main smoothing capacitor C109, originally 1000uf, has been replaced with a 2200uf, and C10 (200uf) with a 470uf.   Hopefully the pictures I've contributed, plus these notes, will be helpful to others servicing or restoring this series of radios.  The replacement transistors I used are Russian devices similar to AF127s, but with pin-outs identical to those of the AF139, which causes sompe problems when fitting them in place of AF117s, which I overcame in two cases, by mounting them 'upside down' and extending one or more of the leads.

Michael Goscombe † 1.8.20, 09.May.15

Weitere Posts (1) zu diesem Thema.

I recently uploaded several photographs of the Motorola 828 together with comments and notes which I hoped would be helpful to other RM members, in the process pointing out that these radios are identical to the Radiomobile 970/980 series, and am wondering why this data has not yet appeared on the relevant pages.  The pictures were taken by me during a repair work I am undertaking on a Motorola 828, and include views of the Printed Circuit Boards, Tuner, etc., and,, as far as I am aware, do not infringe anyone's copyrights.  Are my photos & notes likely to appear soon?

Michael Goscombe † 1.8.20, 07.May.15

Weitere Posts (2) zu diesem Thema.