Making a replica 'Popular Portable Three' HT battery

[Phil G4SPZ]

I have made several replica HT and LT batteries over the years, with varying degrees of success. However they all look brand new, not a problem in itself but I wanted to try making a replica of the pre-war Ever Ready ‘Popular Portable Three’ that looked ‘old’ and more akin to a re-stuffed original, to fit within a recently-restored 1929 Marconiphone 55 portable. Here’s how I did it.

I couldn’t find the artwork on any of the usual sources, but I did have access to an original battery, complete with minor age-related deterioration. Rather than scanning it, I took digital photos of the top and sides with my smartphone, then imported the images into MS Paint and undertook some minor re-touching, mainly to ensure that the images were square and accurately cropped. I printed the images out in draft form, compared the size against the dimensions of the original battery, and determined the print scaling factor. The images were finally printed out onto ordinary white printer paper rather than photo paper, although I have found in the past that matt photo paper probably gives the best results.

I constructed a suitably-sized box made from ‘engineering cardboard’ - the three-ply corrugated stuff that large packing cases are made from - as I find that this is far cheaper and easier to work than more resilient materials, and it forms a perfectly rigid re-usable structure more than capable of holding a dozen PP3s. I used a craft knife, straight edge and set square to cut out the top, sides and base, then glued the box together using PVA woodworking adhesive, which I find to be thicker and stickier than ‘craft’ PVA. Masking tape holds the card in place while the adhesive dries. The base of the box was made removable, held in place with masking tape. The top panel was made from three identically-sized pieces of cardboard glued together to provide sufficient thickness to hold the terminals, which I made from 30mm lengths of 4mm I/D brass model-makers’ tube. Using a set of punches, I formed larger holes in the upper layer, to match the original punching in the top case, and smaller holes in the lower two layers, secured the terminal tubes in place with Araldite on the underside, and poured Evo-Stik into the annular gaps on the top side. This gave a more original look than the melted pitch that I use for grid bias batteries.

I then trimmed the artwork to exact size and stuck it onto the cardboard box using spray mount adhesive, and when dry sprayed the whole thing with a couple of coats of satin finish ‘inkjet fix’ varnish - other brands and products are available. The varnish protects the image, and is absolutely necessary to prevent the print smudging when handled, especially when printed onto matt photo paper. Finally I assembled a pack of twelve pound shop zinc-carbon PP3 batteries, tapped for the voltages I specifically needed for the radio. The batteries were stuck to the underside of the top panel using two strips of double-sided adhesive foam tape. I used insulated cable and wander plugs to connect the leads from the batteries, pushed into the terminal tubes from the inside.

The likely life is around 30 hours at the 9mA drain of the radio. Alkaline PP3s would obviously perform better, but zinc-carbon batteries offer a cost-effective and potentially safer solution - I did not fit a fuse - as the battery sets in the collection only get occasional use. The end result is quite pleasing and was quick and cheap to construct.

If anyone would like a copy of the artwork, I shall be happy to forward the images.

Phil

[HamishBoxer]

Looks superb,another great job.

[kalee20]

Echo HamishBoxer's comments. Great work!

[M0FYA Andy]

I'm puzzled why you wanted the battery to look 'old'. When the radio was in daily use pre-war it would always have been fitted with a new battery which would have been replaced as necessary and never had the chance to look 'old'.
Surely what you want is a battery which looks like it has just been bought in 1929?

An excellent job nonetheless.

Andy

[Phil G4SPZ]

Wow, thanks chaps! Andy, this radio belongs to a museum, and what I wanted to create was the look of a radio and its original battery that had been switched off in 1939, then switched back on again in 2016 and still worked! Mainly for a bit of fun, but I also wanted the battery to match the condition of the radio itself, which has been sympathetically restored rather than brought back to 'as new' condition.

I'll try to remember to take some pics of the radio with its battery in-situ next week.

[M0FYA Andy]

Phil,
OK, I see where you're coming from.
I assume the museum is the radio shop at the Black Country Museum? I used to visit there regularly up until a decade ago, before the row of buildings including the radio shop were built, but this May I spent a long weekend in Birmingham and with a couple of pals I've kept in touch with since university days visited the museum on the Monday. I particularly wanted to see the radio shop and thoroughly enjoyed it, unfortunately you weren't there, but we spent a long time chatting to the lady in the shop.

Strangely enough though, we spent most of the visit in the pub, I can't imagine why!

Andy

[Phil G4SPZ]

Got it in one, Andy! The workshop is only manned on Tuesdays (Wednesdays in winter) by me, and on Thursdays by my colleague Len. Glad you enjoyed the pub all the same! You will have seen the original prototype of the Popular Portable Three below the glass counter in the showroom. I told the lady in the shop that the battery was flat, and she replied "Oh, what shape should it be?"

I'll get my coat...

[Herald1360]

Well it could have been a stack of 1289s!

Though that might be said to be 24 flat batteries, rather than just one.