Re: And the next one! a GEC BT2147
With the new control panel in place [definitely not a job for Interlace] and wired up [urghhhh!] we were getting to the final conclusion of the 'Bakelite Bitch.'
Some small control knobs were sorted and filed down to allow their grub screws to contact the very short spindles on the new presets.
A good test card was displayed with all controls set mid way.
Attention was directed towards the sound or rather complete lack of it. Turning the volume control to minimum resulted in an almost dead HT short!
Metering the control grid voltage on the N78 audio output valve showed the full HT voltage...To cut a long story short the valve has a screen grid/control grid dead S/C. A visit to the valve store will be required.
I usually send Interlace into the loft to sort through the boxes but he is scared of spiders and usually grabs the first valve he sees and returns with everything but the valve you require.
How can you mistake a PX25 for the tiny N78?
Once the sound is sorted it should be about complete. Just a more suitable tuner and I think I know where one is lurking.
The pictures show the rebuilt under chassis and the control panel wiring. Space is very tight!
The last episode soon. [Ha ha!] Regards, John.
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