Ekco AC77

[Joe]

It looks suspiciously like David's has had the lamp-holder changed for a normal BC one.

If you've got dead lamps it's quite possible to smash the glass so you can remove the cap undamaged and then fit it to a new lamp. On the donor you cut the cap off to save the bulb itself. As the original was 200V a 240V lamp should run cool or t could be re-jigged to connect straight across the supply if not.

I now keep the caps off dead lamps so I can convert ES LED ones as they seem cheaper and more readily available then BC ones.

— Joe

[Yorkie]

Thanks for reading the post Dave, which might act as a spur to encourage me to get on with the AC77 and see the job through!

It will be evident in reading earlier posts in this thread that I've put in many hours of work to get to this stage, but it's been spasmodic. Along the way, there have been other diversions - some related to this project - for example, to re-wind the field coil I made a coil winder driven by a sewing machine motor, which became a project it its own right, then I wrote that up as an article which was published in the BVWS Bulletin. Likewise, when I'd obtained some valves of unknown provenance and wanted to test them, my Taylor 45D Valve Tester didn't have sockets for B4, B5 and B7 bases, (even though the Taylor Switch Setting Book had the settings and data for the vales) so I designed and made some adaptors and again, wrote that up to be published in the Bulletin.

One of my concerns was whether the Bandpass Filter Unit which is at the heart of the front end, was sound or defective. If it was duff, that would be curtains, as it's such a rat's nest inside that it would be beyond my wit to repair it. (The maker's original manual says 'don't attempt any repairs - return to the factory'). Earlier this year I checked it out with an Ohmmeter and the results weren't hopeful. I opened it up and the band-switch appeared to be fully encased in metal. However, on closer examination it was sealed with a ring on brown waxed paper around the periphery on the switch. I removed that, and  gave the switch contacts a liberal dose of Servisol while operating the switch. That restored to resistance chart to something like it should be, so I'm hoping that ultimately, that will prove successful. (results attached). I've done no work on it since then.

Turning to the pilot bulb, the bulb-holder in the unrestored chassis picture shown below is the original holder - a normal sized Bakelite bayonet cap as we could buy today, but the bulb was missing. The instructions state: 'This is a special Ensign 200V 12 Watt type connected in such a way that it always receives the proper Voltage if the correct mains tapping is used'. Obviously such a bulb is unobtainable today - the nearest equivalent being a pigmy bulb as used in 'fridges and the like, but they're 15Watt - albeit the bulb will be running on 200V - not 240V, which will de-rate it slightly, but the glassware is quite 'bulbous', so  an alternative might be an elongated sewing machine bulb, which of course have MES bases rather than full sized BC bases, so some adaptation would be needed there, and again, such bulbs are 15W not 12W. There is a heat shield which fits around the metal tube into which the bulb is pushed. I've placed a bulb in the heat shield to show the physical size of the bulb in the pic below, though the bulb is actually located in the tube where the holder is shown in the unrestored chassis pic). I don't think a pigmy bulb is really a runner - I think it would both give too much light, generate too much heat and soon burn out.

All in all, this set wasn't Ekco's finest hour, which is why I guess that thought not valuable as compared with the round Ekcos (of which sets such as the AD65 are just as abominable, with a messy rat's nest beneath the chassis), the A77 is nevertheless uncommon, and for me at any rate, historically worthy of restoring.  I think Ekco's high watermark in terms of thoughtful design and construction is without doubt the A22 - a delight to work on.

Due to other distractions and projects, (the latest of which is to restore a basket case KB 'Toaster' radio bought for a fiver at Golborne), the A77 has languished, but I hope to get back to it over the winter.

I've attached a few pics to help make sense of the above verbose text, which I hope might be of interest.

[AlanBeckett]

Can you cobble together a couple of LEDs and a Resistor and solder them into a Bub Base?
Not very 'Original' but it would get you going.

Alan

[Yorkie]

Thanks for reading Alan, and for your response.

Yes, I'm sure there are lots of options other than the original setup, given the plethora of modern LED lights from which to chose, which will give the right level of light without generating so much heat.

Though ordinarily, the older the set the more sympathetic I am to trying to preserve originality, my outlook has always been safety first, functionality second, and originality third, so without a doubt, the original arrangement can be improved upon.  Primarily I was responding to  'unrealdave's' query about the bulb arrangements, the upshot of which is that it was a poor design originally, and the bulbs have long ceased to exist.  However before I get to the stage or sorting out the dial light, the chassis needs to be rewired and paired with the power supply chassis,  so there's much work still to be done.

I've been side-tracked by a domestic project - the electric remote garage door operator has decided to give up the ghost. It's worked faultlessly since I installed it about ten years ago to replace one that had packed up. Yesterday the remotes wouldn't work, but it works when the  wall mounted directly wired push button switch is pressed. I've tried reprogramming the remotes to no avail, and basically, the upshot is that the 'logic board'  - quite a complex thing with SMDs and ICs on a double-sided PCB, has developed a fault. A new board is available at £100 or so, but a complete new garage door opener can be had for £200 or so. Hence, it's a high risk strategy to fit a new board if something like the motor packs in err too long.

There's just one electrolytic on the board, which I'll change, if only out of curiosity, but I think it unlikely that it will effect a cure.

I mention this not to take the thread off topic, but to indicate how we get thwarted from single-mindedly pressing on with our restoration projects!

But then radios are a hobby and hobbies are about the enjoyable use of scarce leisure time - not the be all an end all.

You'll know the feeling very well Al, given your own commitments.

Hopefully, as the winter advances, so will the AC77 project, even at this glacial rate of progress.

I'll update the thread if there's anything to report.

[Joe]

Why I thought the lamp-holder had been changed is that the trader sheet says :—

Scale Lamp.:—This is a special Ensign Tubular type, with a centre contact SB cap.

— Joe

[Yorkie]

Why I thought the lamp-holder had been changed is that the trader sheet says :—

Scale Lamp.:—This is a special Ensign Tubular type, with a centre contact SB cap.

— Joe

That's well spotted - I'd not looked at the Trader Sheet - only the Ecko data and the W.E.T data, each of which simply mentions the bulb - not the holder. If the holder on mine had been changed it must have been a very long time ago in that it's definitely a normal BC one and was a tight push fit into the metal sleeve. An SBC or SES holder opens up more possibilities for a more compact less powerful bulb.

Thanks for spotting that Joe - I'll print off the Trader Sheet.

[Radio Fixer]

On my AC97, same switch coil arrangement, I actually took out the switch circlip holding the rotor. Not too hard with sharp side cutters but practice on old pots first !! It does allow the rotor to be pushed back giving better access. There was lots of goo and gunge under mine. It did allow better cleaning I think.

I'm not sure about Servisol switch cleaner although I did use it for years. It doesn't seem to do a job that lasts very long before intermittency is back. De-Oxit as sold at the BVWS stall seems far better even though it is expensive, last for ages of course.

Gary