Another Ever Ready .... 5216 this time

[Amie]

Hi all.

In response to an appeal by my friend on the other radio forum for some information about the measurements of the MW frame aerial that would have originally been fitted to my Ever Ready 5214, Electronpusher, Peter, from Sussex, kindly offered a complete set.

Well, long story short, it arrived today, and although not strictly a 5214, (it was originally blue in colour, so is a 5216), it has its aerial still fitted to its back cover and is reasonably intact, and therefore we will be able to finally remake the aerial for mine.

I haven't checked the rest of the set out yet, but seems everything is present.

Its not the very earliest version but was fitted at manufacture with all CT 8 valves. Unfortunately someone decided at some point to do a, (very bad paint), job on it. I don't believe the cabinet ever had anything more than a painted finish though, and was never a rexine covered one.

I'm hoping that there is sufficient "right" with the internals that it can be brought back into the land of the living, and enjoy being part of the Amie Ever Ready fleet.

[Kalee20]

Looks good!

How about a photo of the inside, too?

[Amie]

Looks good!

How about a photo of the inside, too?

For you Peter here's two! 

[FIXITNOW]

Nice set not a version I have but worth looking out for ,Good luck

[Ed_Dinning]

Hi Folks, I have a version of this set, it has Ct bases fitted but all 4 are fitted with what looks like factory made adapters to octal bases that are fitted with DK series valves

Ed

[Amie]

Hi Folks, I have a version of this set, it has Ct bases fitted but all 4 are fitted with what looks like factory made adapters to octal bases that are fitted with DK series valves

Ed

Hi Dr Ed.

I'd be interested to know if the adapter bases convert the octal pin outs to the CT8 orders of connection? For example CT8 pin 2 and 3 are filament, on octal its 7 and 2. There are also other differences.

Or are the CT8 bases wired to suit the octal pin out order?

I expect the octals you have in your set are the American GT "short" valves, as in my 5214, I have some spares, plus some post war Mullard octals that are electrically compatible but if seated in adapters wouldn't allow the back to be in place as they are too long for the extra height of the bases.

This set is a little confusing as it has a date stamped electrolytic, chassis, and speaker, all 1943, but has the earlier oscillator coil in can above chassis, and, the tuning dial is marked with pre war station positions and is medium/long wave being after the Droitwich transmitter was shut down.

There is a bit of a setback regarding the restoration, in that checking the valves out fitted to the set, the DK1 has an OC filament, the DF1 and DAC1 have no emission, and the DL2 is very low.... Of course I haven't any of those or a replacement speaker that's needed, so the searching will start soon.
On the bright side the output transformer does seem in good order electrically.

Amie.

[Kalee20]

Definitely an enigma

It's possible that it might have been pre-war, and had one component replaced in its early years, giving rise to a 1943 date on that item - but not the electrolytic, the speaker, AND the chassis.

Is there any clue in the serial number - Ed and Amie, put them both up, it might give a clue to which came first?

[Amie]

Chassis is stamped 2168624

[Amie]

Hi all.

So, I've done a little more to this set, both the aerial frame coils were in a complete but sorry state: and I've now stripped dried and varnished the plywood former that the LW winding was on, the coil itself was still functional, but the form had shrunk over its ≈ 80 year life and the winding was loose to the point of falling off.

The original wire was single enamel but with a cotton or silk cover it was in good condition so I rewound it after the form was finished, thankfully, the coil had value of 1.76mH, same as before. This coil is mounted on the side of the set at right angles to the MW frame.

The MW frame coil is the reason that this set came to me in the first place, basically I was trying to find exact details if how they are made, as my other all dry Ever Ready had an inadequate lashup, and I was offered this set as a reference source: for which it has proved invaluable.

As I said the set was built as a 5216, meaning that it was a painted blue with black crackle finish, though this one had acquired a bad beige paint job. I asked a local furniture restorers opinion who said that it was acrylic silk emulsion and supplied me with some spirit cleaner that I've used to remove the beige abomination, and the back is now returned to the original, if worn in places, finish. I may just clear coat it if the rest of the set is as good condition, I think that a bit of life wear and patina is worth preserving.

The frame coil for MW on these earlier style sets (with a LW band), is fitted to the back of the set. In practice it seems it's a crummy idea, as the coil and the connecting wire is vulnerable to damage, but it is the original design so I wanted to have "my" set as built, and therefore copied this one, which needed the corner blocks re gluing and wire replaced.

As an aside, I had always wondered how it was that sets with a frame coil could be accurately aligned, but the ER has a clever if untidy method of adjustment. About a third of the final turn of wire is run loosely inside the frame coil to the terminal tag, this wire if moved to the middle of the back away from the rest of the coil lowers the inductance of the coil: if its run nearer the rest of the coil its inductance is increased, (at manufacture the final position was fixed with the aid of the staple gun in keeping with Ever Ready's high build quality standard!) It means that an adjustment range of ±10uH can be achieved. Clever.

Just in case anyone else gets stuck, the vital statistics for MW coils are as follows:
former depth overall (including ⅛" lip) 1½"
former width overall 11¼"
Former height 7"
Tuned winding 20 turns 0.5mm ø single silver plated ttfe insulated, (originally rubber over cotton covered copper single).
Aerial winding 1 turn 0.5mm ø ECW.

[Kalee20]

As an aside, I had always wondered how it was that sets with a frame coil could be accurately aligned

It seems to me, a lot of them just couldn't be accurately aligned. And, it's not restricted to sets with a frame aerial.

Ever Ready Model K has a non-adjustable frame aerial. So does Vidor CN420a and Bush DAC90a. Cossor 500 has a non-adjustable RF coil. As does Pye 67a. That's 5 come to mind.

Alignment technique, after getting the oscillator 'right' is to tune to somewhere in the middle of the band (usually specified), and adjust a trimmer capacitor. It'll be spot-on at this point. But it's like trying to define a straight line by giving one point only - if the gradient of the line is wrong, there will be an error each side, of opposite sign. Component tolerances and Sod's law says that, in production, the gradient WILL be a bit wrong, and tracking WON'T be optimum.

A lot of radios leave something to be desired, and it hurts sensitivity.

Being able to vary both the coil's inductance and the tuning gang's parallel trimmer, does allow tracking to be adjusted spot-on at two points, and the error elsewhere is then very much less. Down side is, the extra time spent in test puts up the price, as does a coil slug if used. But it does allow the circuit to give more nearly its best, which is more rewarding from a designer's point of view.

I've not seen the technique described, but I have read about it. Though blobs of wax would've been far nicer than a staple...