Re: Baird Garrick
Hi all,
an update on the Baird.
I drew out the circuit of the TV sound section (attached). Notice the inefficient capacitor coupling between stages. Also the aerial input coil needs to be terminated with load of the aerial input of the vision section in order to work properly.
The TV sound section was unstable at high gain. I found that C4 was missing and that R7 had been replaced with 100 ohm and 150 ohm resistors in series. The remains of C4 could be seen soldered to the chassis, so I found suitable vintage parts and fitted them. The sound TRF unit is nice and stable now.
I made a small aluminium plate to cover the hole that had been left by moving the mains voltage selector. I also replaced the 50s double insulated mains input cable with a twisted pair of blue and black wires as it would have had originally.
The back cover of the set has now been drilled and routed and the brass screw cup inserts have been fitted. The mains input hole needs to be filed into a slot and the CRT neck box needs to be assembled.
The rear controls do not extend as far as the back panel, so it is a case of having to stir around the controls with your fingers! To make things more interesting the identity of the rear controls are not marked on the rear panels of the other sets I have seen.
That's all for now.
Cheers
Andy
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