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Forum 135

[Closed] Beau Decca Mirror-lid TV/Radio - spot the theft.

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Till Eulenspiegel
(@till)
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Looks as if I got it wrong about the speaker on top Defiant. It seems that there was no such model with the two part chassis.

Till Eulenspiegel.

 
Posted : 16/02/2014 1:43 pm
Till Eulenspiegel
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Tried it today. The Decca 1000 chassis will not fit into the Beau Decca. Dimensions apart, the 1000 chassis is far too populated with components which prevent the chassis being inserted in the available space at the top of the cabinet. You'll note that the correct chassis is void of components at the user control end. The chassis is located into a felt lined box like structure at the top of the cabinet.

Till Eulenspiegel.

 
Posted : 25/02/2014 1:08 pm
Till Eulenspiegel
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Pictures of the development chassis which was intended to fit into the Beau Decca. In the end the chassis from Defiant was modified instead. This contraption actually worked and was tested in the Defiant. The design consists of elements of the Plessey Mark 1, note the RF/IF unit, this was modified with the addition of an audio amplier stage using a Mazda 6L18 triode. The Mark 1 line output transformer was used but not in a self oscillating manner, a Mazda T41 thyratron oscillator was employed. An EL38 or Mazda 6P28 line output valve. The sync seperator and frame timebase are similar to the Beau Decca and the Defiant TR1247. A 6D2/EB91 as the sync separator followed by a Mazda 6F14 sync amplifier. The frame timebase consisted of a Mazda T41 thyratron oscillator and a Mazda PEN45 for the frame output.

The original power supply unit was retained with no modifications except for the omission of the mains EHT transformer.

A blank chassis was made for me by an engineering firm near Gateshead.
Get the circuit design right and I will transfer the components on the development chassis to this one.

Till Eulenspiegel.

 
Posted : 25/02/2014 2:01 pm
Brian Cuff
(@briancuff)
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I've yet to get the chassis out of my Beau Decca so I have no idea of how it looks. At least remaking the PSU chassis doesn't involve any scan/RF stuff so it should be reasonably easy unlike your project, Till!

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Posted : 25/02/2014 2:31 pm
Till Eulenspiegel
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Converting the Defiant TV chassis for use in the Beau Decca necessitated fitting this complex switch assembly. The five position switch selects TV, radio and three tone compensated gram inputs.

Till Eulenspiegel.

 
Posted : 26/02/2014 12:15 am
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