[David G4EBT]

As mentioned in another thread, I bought this set back in 1985 with a view to restoring it, but when I took the back off and looked inside, I put it in a dark corner of the left and forgot about it till it resurfaced when we move house in 1991, when it went back up into the loft again and was once more, forgotten about. Then in 2013, when fumbling about it the loft, I came across it again, and dithered about whether to offer it for spares, or do a total strip-down and rebuild.

The only thing I'd ever done that came close to that was to used an R1155 as a donor set, saving only the 'switchery', coils, IFTs and so forth, fitting an integral power supply, output stage, speaker, BFO and S Meter, a new front panel and fitting more modern valves. That was based on an article in Short-Wave mag, and served me well for several years.

There were a number of factors to weigh up before jumping in:

Firstly, the screen-printed glass dial had lost more of its lettering and a scan wasn't available to attempt to replicate it with a waterslide transfer. Without a new dial it would have been a non-starter. Luckily, someone alerted me to the fact that Ben Djikman in the Netherlands had them on his website, albeit with continental spelling of some stations. I contacted Ben to see if he could do the dial with English spellings throughout, and he said only if I could get orders for a batch of ten to be made. With an uncommon set such as the AC77, of no great value and not sought after, that seemed unlikely, so I opted for the one that he had, and excellent it is too.

Secondly, was the mains transformer and output transformer windings intact? Had they not been, rewinds would have been too expensive to contemplate. Luckily, they were both intact, though the mains transformer voltage selector panel needed replacement.

Lastly, was the field coil on the mains-energised speaker intact? No, it wasn't, but otherwise, though rusty, the speaker was in sound condition. I figured that I could rewind the field coil, as indeed I did. But with 2.3kms of wire and 20,000 or so turns, that sidetracked me into designing and building a coil winder, powered by a sewing machine motor. More of that later.

I decided to set about restoring the power supply chassis first. This is connected to the upper receiver chassis via a wiring loom, which terminates on a crude tagstrip arrangement at the rear of the power supply chassis, which has a mating tagstrip, the two being soldered together. For me, this was an example where originality had to be sacrificed for reasons of safety and serviceability, so I designed a new tagstrip with screw terminals, and a safety cover. This entailed turning brass terminals on the lathe, and making a printed circuit board strip into which the terminals were soldered. Pictures will make this clearer later.

The chassis had one electrolytic can mounted above chassis, and a two 8uF caps in a cardboard box which was a 'service replacement' probably fitted during the war years beneath the chassis, either on a DIY basis or by an unskilled bodger. The clip meant to hold it in place was missing, crudely soldered live connections had been covered with fabric insulation tape, and the box was swinging loose on the wires. I decided that the best solution here was to make a new 'box' with double sided PCB material, and to create a brown paper label to roughly replicate the old one, then to make a clip to fit the new box in place.

The vertical 16uF can above chassis was scruffy, so I decided to clean it up, re-stuff it and to create and fix a waterslide transfer to say what the cap is.

The first task was to remove everything from the chassis, to de-rust it using a 'power file' and rust inhibitor, then to use an acid etch primer. Gary Tempest tipped me off that the nearest colour to Ekco chassis was Halfords own brand Ford Dove Grey, so I gave it a couple of liberal cots, then when dry, set about fitting the components back, fit the new tagstrip, and rewire the chassis.

The first pic shows the PSU as found. Second pic shows the unsoldered two-part tag-strip which joins the power loom to the receiver chassis. Third pic shows the underside of the chassis with the service replacement twin 8uF paper box capacitors hanging loose on taped up perished wiring. Fourth pic shows the poor state of under chassis wiring, and the last pic is the power supply stripped ready for de-rusting with a power file and priming with acid etch primer.

In the next post I'll cover the rebuild of the power supply.