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Front View [22K]

  • Circa 1949
  • 9" Mazda CRM92 CRT
  • Band 1 T.R.F.
  • 15 Valves
  • A.C. mains only
  • Original Cost : Unknown
A fairly large console set with a teenie little 7.5" by 5.5" viewable screen.

The two chassis layout is typical of the earlier style of console set with a seperate power supply chassis mounted in the bottom of the cabinet.

Click on image for lareger view [110K]There appears to be a slight conflict over the numbering used for Masteradio sets. Refering to the service data the set was available in two forms, the BT509 for the Birmingham area and the LT509 for the London area. At the time, these were the only two transmitters in operation. In addition a "fringe" area model was made available which would have an additional arial input amplifier, identified by an additional letter "P" after themodel number. However a period advertisment (curtosy of suggests that models 409/412 were for London and 509/512 were for the midlands. Interestingly, this 509's cabinet seems to use the radiogram cabinet !?
Both the line and frame timebases are based around gas filled valves, a style that would cease to be used within the following couple of years.

Although the set is intended for AC operation only, the mains transformer is in fact an auto-transformer and hence one side of the mains supply is still connected to the chassis. Oh good :-(
WHERE I GOT IT Rescued from next to a dustbin in Tamworth (thanks Ricky "Big Muff" and Ant "Doc Decibel").
SERVICE DATA Although the set is missing its back, the T509 service data in one of the Television & Radio Servicing books seems to match this set.
CURRENT STATE The woodwork certainly needs stripping and re-doing, as just resting your hand on the top is enough to remove part of the surface ! I'm also not sure whether the control dials are the original, though the central on-off-volume dial was missing, a reasonable stand-in being found at the N.V.C.F. On the plus side, however, theres no signs of damp or electrical disasters.

Barely visible on the top is the gold lettering "MasteRadio" in a script font. Can anyone send me a picture of how the text should appear?
Download Service Data [722K] This data covers Masteradio models T409, T509, T412, T512 and T612.
Period Ad [110K] Advert from unknown magazine.

Front View [29K] Power supply chassisEHT Connection

All images copyright
J.Evans 2000-2004
Last updated
10th February 2004