Ekco AC77

[Yorkie]

Thanks for reading and for your kind comments Colin.

It's been cold but sunny today so the greenhouse has been nice and warm. Hence, I've been able to give the chassis a couple of coats of gloss and I'll leave it alone now to harden off. I've considered alternative ways of connecting the power supply chassis to the main chassis in a way that permits disconnect as required.

The original twin tag-strips which were soldered together simply are a non starter, and like other aspects of the set this is a manky cost-cutting arrangement which doesn't lend itself to later servicing. Initially I fitted a turret strip to the restored power supply so that the eight wires of the harness to the main chassis and two to the field coil on the speaker can be soldered through the turrets.

However, though they could individually be unsoldered as desired if need be, I wasn't happy with that, so I've been busying myself on the lathe today making ten brass terminals from 0.25" diam rod, which I've internally threaded 4BA. The terminals will be soldered into a strip of PCB on which I'll etch pads on the reverse. This will allow eyelet terminations on the ten wires which need to be externally attached to the strip, so that any or all of the wires in the harness to the main chassis/field-coil can be disconnected as required.

That's the theory, but of course, the difference between theory and practice in practice, is often greater than it is in theory. I'm just making it up 'on the hoof' as I go along, so if it works, I'll update the post. The sharp-eyed may notice that there are only nine terminals in the pic - one has already disappeared on the trip from the garage to the study! Ho hum.

I've attached a pic of the original twin tag-strips unsoldered on the then unrestored power supply chassis, then an external view of the turret strip I'd fitted, and finally the terminals I've made today for my latest notion. (The options are limited due to the small amount of clearance from the chassis to the backboard).

I know that others may disagree in their approach, but my priorities when restoring a set are safety, performance, reliability, serviceability, and lastly, originality.

Hence, the original tag-strip had to go, and there's no way that I'm going to used the same colour code for the wiring that Ekco did - using both red and yellow for HT, and also yellow for some ground leads. Maybe there was some logical reason for that, but if so, it eludes me. I can just imagine the discussions in their R&D Dept at Ekco back then if they were told that a new colour code was to be introduced for mains flexes - 'brown, green blue': "Yes that would work - blue is the colour of the sky, the sky is high up, so that will be HT. Brown is the colour of earth, so that's the earth sorted, and green is grass, which is just above earth so that will be neutral. Great idea"!