940

Eddystone, Birmingham

Data
Forum
Pictures
Collections

  • Year
  • 1962–1970
  • Category
  • Commercial Receiver (may include amateur bands)
  • Radiomuseum.org ID
  • 109326
    • alternative name: Stratton & Co.Ltd.; Birmingham

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

 Technical Specifications

  • Number of Tubes
  • 12
  • Main principle
  • Superhet with RF-stage; ZF/IF 450 kHz
  • Wave bands
  • Wave Bands given in the notes.
  • Power type and voltage
  • Alternating Current supply (AC) / 110-125; 200-250; Volt
  • Loudspeaker
  • - For headphones or amp.
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: 940 - Eddystone, Birmingham
  • Shape
  • Tablemodel, low profile (big size).
  • Dimensions (WHD)
  • 425 x 222 x 381 mm / 16.7 x 8.7 x 15 inch
  • Notes
  • General coverage receiver, 480-1030 kHz / 1,03-2,4 / 2,4-5,4 / 5,4-12,7 / 12,7-30 MHz; AM, SSB (BFO);
    S-meter, crystal filter.
  • Net weight (2.2 lb = 1 kg)
  • 19.5 kg / 42 lb 15.2 oz (42.952 lb)
  • Price in first year of sale
  • 153.00 GBP
  • Source of data
  • -- Original-techn. papers.
  • Author
  • Model page created by a member from A. 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: Eddystone,: 940

Threads: 2 | Posts: 2

After using the set for some time, I noticed spurs at several points on the highest frequency range. Some investigation with a hand-held scanner revealed that the ECC189 was oscillating quite strongly at about 60 MHz. Further checks revealed that the problem was also present on the 2.4 - 5.4 MHz range, but I hadn't noticed because aerial noise drowned out the offending spurious responses. They were audible when the aerial was replaced with a 47-Ohm resistor. The spurs on the highest frequency range  are also very quickly "tuned through" and may not be noticed.

The ECC189 has a grid stopper, and the grid of the second half of the cascode combination is directly grounded via a number of almost inaccesible capacitors. I am not convinced that these have deteriorated, and suspect that the problem may be caused by my using a different make of ECC189 from that originally in the set. Its also possible that many 940s had this problem from new. None of my ECC189s are Brimar or Mullard.

The problem was solved by using 47 Ohm anode stoppers wired to the wavechange switch as in the attached photo. The performance of the set hasn't changed with these additions. Using a single resistor was considered, and rejected because of the difficulty of accesing the valve base.

Comments invited - Bryce

 

Attachments

Bryce Ringwood, 14.Jun.09

Weitere Posts (1) zu diesem Thema.

The following may be of interest:

An article in Short Wave Magazine (Aug to October 1988) issues gave instructions for "restoring" (in fact modifying) the Eddystone 940. When purchasing a 940, be aware that it may have been modified and that these changes may not be what you want. The changes  to the i.f transformers may be difficult to reverse. 

Bryce Ringwood, 13.Jun.08

Weitere Posts (1) zu diesem Thema.