Ekco AC77

[Aerodyne]

Great work, David. As Col says, you'll get a kick out of hearing and seeing the finished set working. If you haven't as yet stripped the main chassis completely, and are open to a tip, here's mine: take lots and lots of digital photographs, varying the angle of view and close-up as well as back a little. Rebuilding is, I find, made simpler when you have a clear record of what went where. I've offered this 'advice' but I'm aware that Granny already knows how to suck eggs...
Tony

[Geaney]

Great work David. It never occurred to me to use a decal to replace the wording on an electrolytic can - and I've cleaned quite a few where I left the original wording and thus a dirty patch on the can!

I've also not tried out the silicone rubber wire so that's another item for me to consider.

Looking forward to seeing the rest of the restore.

Cheers, John

[Yorkie]

Great work, David. As Col says, you'll get a kick out of hearing and seeing the finished set working. If you haven't as yet stripped the main chassis completely, and are open to a tip, here's mine: take lots and lots of digital photographs, varying the angle of view and close-up as well as back a little. Rebuilding is, I find, made simpler when you have a clear record of what went where. I've offered this 'advice' but I'm aware that Granny already knows how to suck eggs...
Tony

Very wise words Tony. Even with the simple PSU chassis although I took several pics, I could have done with taking a few more. I've only had a peep at the main chassis, and although it doesn't have a high component density, I can see that everything is going to have to come off and the chassis de-rusted, re-sprayed and rebuilt. The frame of the three gang tuning cap is quite rusty, so that's going to need attention. I'm not sure what style of bulb the 'pilot lamp' is - it's referred to as a 'special' Ensign 220 Volt 12 Watt and is fed from the primary of the mains transformer. I don't know if its an MES pigmy bulb as are fitted in fridges, microwaves or a sewing machine type bulb. I can see that being fun and games!

I don't see me finishing the restoration any time soon, but it will certainly keep me occupied through the winter months

[Yorkie]

Great work David. It never occurred to me to use a decal to replace the wording on an electrolytic can - and I've cleaned quite a few where I left the original wording and thus a dirty patch on the can!

I've also not tried out the silicone rubber wire so that's another item for me to consider.

Looking forward to seeing the rest of the restore.

Cheers, John

Initially I bought a few sheets of decal paper with a view to making decals for glass radio dials, but that has yet to come to pass. Many, if not most dials are printed on the rear, so the text on the transfer has to be reversed, and what you see through the glass is the back of the transfer - not the front. If all the water and air bubbles are smoothed out, I see no reason why if ought not to look good, but it's something I've never tried. What did impress me was how well the printing came out - very dense. I thought it would be a failure as my printer won't print onto acetate, so I thought maybe it wouldn't like decal paper, but it printed fine and the decal itself seems quite durable. I might try making a reverse printed dial when I get a bit of time, though I've nothing in mind. The firm who supply the paper - 'Crafty Computer Paper' now do a tougher paper that is dishwasher proof and I imagine that it would be excellent for radio dials where heat may arise from dial lamps. You can watch short little instructive videos at the website:

http://www.craftycomputerpaper.co.uk/.-M...dium=email&utm_source=Crafty+Computer+Paper+%2f+Specialist+Crafts&utm_campaign=3043215_a3+decal+paper&dm_i=IYT,1T85R,2PVBU9,6H8S8,1

As to the silicone rubber wire, Phil Marrison is the only chap I've come across who sells it by the Metre. I think there are about ten muted colours in two multi-strand gauges that he supplies. Phil started buying it for his own restorations, but it comes in 100 Metre reels, so he began selling it. Not really in business as such - just a hobbyist like us. I usually get ten Metres of most colours at the NVCF in May and it sees me through the year.

Phil is known as SWB 18 on the VRF, where you can PM him for details of colours and prices.

[Yorkie]

I've been making steady if spasmodic progress on this radio and have removed and cleaned all the components such as tuning cap, IFTs, OPT, tuning drive and have removed all of the old wiring. I've made careful drawings to (hopefully!), minimise the chance of wiring errors when re-building it. There was no prospect of leaving the chassis as it was - though it's almost 80 years old, it wasn't well painted in the first place as will be evident from the pics, but fortunately the rust wasn't too deep.

Recently I made an impulse buy of an 'electric file' on offer cheaply at Aldi - one of those jobbies which had a 1cm wide continuous belt. Didn't know how it would stand up and I did wonder if the narrow belt would keep popping off. I thought it might prove useful to de-rust the chassis so I gave it a go this afternoon and was agreeably surprised. It has electronic speed control and I set it at the lowest speed. It only took about 45 mins to de-rust the whole chassis, though there were some nooks and crannies which needed to be finished by hand. I used three of the small sanding belts in the process and found them surprisingly durable. (They're about 45cms in circumference). I then gave the chassis a good going over with Jenolite rust remover, cleaned it off, rinsed and dried it with a hot air gun, and have since given it a coat of acid-etch primer.

When I've rubbed it down and given it another coat of primer and top coat, I'll post an update and when I get a few mins, I'll take some pics of the cleaned up components ready for installation.

Ordinarily, I wouldn't bother to re-stuff caps, but the ones in this set are in waxed cardboard tubes and far larger than their modern equivalent, so I decided to retain and re-stuff them so that they look more in keeping - not that they're on display. I removed the pitch from each end, desoldered and removed the wire terminations from the eyelets, fitted a new cap with wire terminations through they eyelets, then sealed the ends with two-part epoxy know as 'Super Steel'. Despite its name, it isn't steel and it's none conductive (Ive laid a strip on glass and subjected it to 500V DC and 1,000V AC on a lekage tester and it shows no sign of leakage). The merit of Super Steel is that it dries to black gloss and looks just like pitch. It's extremely hard and I've used it for such things as filling holes in die-cast aluminium boxes, and repairing Bakelite cabinets prior to spraying. It sands very well and when sanded takes on a dull grey (steel like) appearance. (You can get it on e-bay as well as shops such as Halfords). I've attached pics of a cap and the product.

Really, this unexceptional (if old) rather shabbily built set has little to be commended and doesn't warrant this degree of attention, but for me, it's a first attempt at totally stripping down and re-building a set with little regard for the time and cost. (It's a hobby innit?)

Hope that's of interest.

[Radio Fixer]

Coming on very well David. Might have to add one of those mini belt sanders to the growing tool collection. You can never have enough.

The cap re-stuffing is very neat, nice to have an eyelet for reinforcement. The Super Steel as a pitch sub is a good tip and I will add it to my tips list, thanks.

Thanks for posting the pics, interesting.

Gary

[Yorkie]

Thanks for reading my post Gary, and for your kind words of encouragement!

[Joe]

You're a braver man than I am, David.

On the rare occasions I've re-stuffed caps I've re-used the pitch. I'm not knocking your method; just confessing my own tight-fistedness.

- Joe

[Aerodyne]

The chassis certainly cleaned up well with the sander. A very useful bit of kit, must watch out for one. It will look great when painted. Don't be tempted to paint the underside, or you'll have to clear paint away to make chassis connections (unless that's your plan, of course)
A very worthwhile project and despite your thoughts on the unworthiness of the set, I believe the efforts are merited and in any case, knowing you, David, you would never do less than your best, whatever the task in hand. I'm keen to see your progress.
Tony

[Yorkie]

Thanks for reading my post and for your kind comments Tony.

I can certainly recommend those little belt sanders - they come with three types of 'heads' and have a quick release lever to make belt fitting easy. You just move the lever, remove the old belt, fit the new one and move the lever back to tension the belt.

I'm intending to paint the chassis as it was before Tony, but of course at grounding points I'll clean the paint off to make good contact.

I've sprayed the chassis with acid etch primer, which I'm impressed with. It's from the e-bay shop of a firm of auto factors who all all sorts of aerosol spray paint and sundries, and they do a twin pack of 500mL aerosols for £13.00 post free. Very good spray heads that spray about a 4" wide strip at about 8 - 10" distance. Quick drying too. You can recoat in 15 mins, then have to leave it 24Hrs before applying the top coat. I put the heater on in the workshop at 8am this morning, then when I went out at 11am it was nice and toasty and up to temperature for spraying. If we get a sunny day as forecast tomorrow, I'll apply the top coat in the greenhouse as it's much more dust free. I'll use Halford's Ford 'Dove Grey' which Gary tipped me off about as being a very good match for Ekco chassis of this vintage.

The link to the auto factor paint firm is here:

http://www.ebay.co.uk/itm/271356235244?s...K:MEWNX:IT&_trksid=p3984.m1439.l2649

I've attached a pic of the primed chassis.

This set has some peculiar construction features.

For example, if you look at the pic of the screened lead to the earth socket, you'll see that apart from the screening being grounded at the earth socket and at the chassis (on top and bottom via the grommet), there is also a tandem yellow wire grounded at both ends, running adjacent to the screened wire. Why yellow I wonder, particularly since yellow is used as the HT supply from the power supply chassis, whereas the ground lead from the PSU is black. Huh - what's that all about?

I've never seen this method of screening a wire either - it has close-wound 26SWG tinned copper wire. Effective enough but I've only ever seen woven mesh screening before.

I have to say that the standard of design construction of this set is in my view very poor in many respects. Notwithstanding that it's almost 80 years old, the paint on the chassis is just a few microns thick and can be flicked off with a fingernail. Perhaps it reflects the poor state of the economy in the mid 30s depression era - corner cutting left, right and centre?

Design wise, one end of the chassis has quite a low density of components - the other end has them all cramped together. There are two manky 'tag-boards' which is a bit of a misnoma because the boards (flimsy 1mm thick paxolin) don't have any tags on them - just a few slots with the wire ends of components trapped in the slots with blobs if solder to the next wire. To try to be in keeping, I've therefore replaced them with two similar sized little turret-tag boards, re-using a couple of wirewound resistors which were in spec, and re-stuffing caps. (Only one side of the new boards is shown - there are components on the reverse side too). I recently saw inside a circular Ekco AD65 - appalling - just a rat's nest of untidy wiring and from the same vintage. What a contrast is the wonderfully designed A22, which is a delight to work on, has several novel features, and must be Ekco's high water mark. Or so it seems to me.

Hope that's of interest.