Two BRC 2000 CTVs needing attention.

[Geordie McBoyne]

The two BRC 2000 series colour TVs in my collection need repair and then the possibly of fitting a transductor to remove the pin cushion distortion inherent in these otherwise fine sets.
Any other modifications to improve performance and reliability will be considered.
The sets are a 19" Marconi 4701 and a 25" Ferguson 3700.
Starting with the Marconi.    
The loudspeaker employed in this set is a 20 ohm 6 X 3 inch elliptical type.
Being unable to find a direct replacement I've fitted a pair of 9 ohm units removed from a scrap LCD TV.
In order that the new speakers will fit in the position of the original unit an adaptor plate will be required. This new part has now been made and fitted. Now all that is required to do is refit the chassis and find out if it works.

Geordie McBoyne.

[Refugee]

I saved a couple of flat screen speakers that may well fit side by side in that space.

[Murphyv310]

Yuk!!
Flat screen speakers in a proper telly, no no no.
What are the dimensions of the original and impedance? Those little speakers are a joke with awful frequency response.
I'm sure someone would be able to get something more appropriate.

[Geordie McBoyne]

Hi Trevor,
              Much better now that the speakers are fitted in the BRC 2000 CTV.   A pair of good quality units made by Philips in Hungary. Refugee wrote: "I saved a couple of flat screen speakers that may well fit side by side in that space."
Hi Refugee,
The original loudspeaker was positioned in the same manner as the replacement assembly.
But your right, there's space for a much bigger and possibly a round LS.

Geordie McBoyne.

[ppppenguin]

The ohter way would have been any speaker of the right size and a small autotransformer. For an 8R speaker that would have been about 1.6:1. There's no DC in so it won't be too critical. I'm sure Ed DInning could suggest suitable dimensions and turns.

[Ed_Dinning]

Hi Gents, yes an auto wound transformer would do nicely and be small and compact.

However I must confess I assisted David in his actions by providing hole cutters for the manufacture of the adaptor plates.

Ed

[Murphyv310]

Sacrilege Ed .
Go and sit on the naughty chair.
An auto tx is neat and simple.

[ppppenguin]

Seeing Ed and David conspiring like this reminds me that Ruth and I will be in Newcastle on the nights of 26/27 June. Would be good to meet up with both of you if possible. This really needs to go in another thread or PMs or emails.

[Geordie McBoyne]

Well anyway the twin loudspeaker contraption works delivering plenty sound as so it should considering the audio amplifier employs two BD116 power transistors. There is some intercarrier hum to attend to, can't blame the speakers for that.

Now to move on to the vision circuits. The present tests are carried out with the EHT generator panel removed.

Geordie McBoyne.

[Refugee]

I must have scored better with my speaker salvaging from a dumped flat screen TV.
There were two pods with two speakers in each. I am not even sure if there are crossovers in them.
I just took one driver out randomly and connected it to my LCR bridge on completion of its restoration to see what would happen if I put my finger on the cone of the salvaged speaker.