Battery cover scan available in the Technical library
Based on Bill Morris (aka Battery Maker) scan but some text replaced and scan resolution fixed. Print at 150dpi. Finished box less than 45 x 61 x 45 mm ex contacts. Cut up a PP9 connector. PP3 or 6 x AAA (better) will fit.
Use general purpose or contact adhesive for tabs in order shown.
Score folds in advance with butter knife or ballpoint pen on inside. Note that tabs B are folded to shorter height to fit inside large outer flaps.
Use 2 x 3 way, or 2 x "flat 4 way" cut up, or a "2 x2" 4 way + 2 way AAA holders stuck with double sided foam sticky tape.
The rivets go loose when you solder, so tuck wire through rivet hole and solder on inside or solder to spring. The connectors are cut up PP9 and attached to battery holder with double sided foam sticky tape.
Velcro is stuck to outer bottom flap and battery case.
You can spray or paint varnish the box. Use 90gm paper and spray mount or "pritt stick" to printed side of cereal packet. 160gm directly printed card is too light weight. I always print and make a paper only laser printed model first.
The finished article
1) A ZnC layer cell PP3 is about 400mAH to 450mAH. [0.75]
2) An Alkaline PP3 uses 6 x AAAA instead of layer cells so is 550mA to 590mA. [1.50]
3) Fully filled ZnC AAA cells are 540mA, but all the cheap AAA are partially filled, assume about 490mAH to 510mAH. [0.75]
4) Alkaline AAA are 1150mAH and seem to be always fully filled. [2.25]
PP7s are not available locally and are very expensive online. Prices in [ ] are Euros for 1 x PP3 or 6 x AAA. Your Aldi / Lidl and local Poundsworth /Euro-bargain store may vary. Those are best Limerick prices. (AAA JCB "Zinc" are currently 14 for €1.50, but I priced at the more common 12 for €1.50)
You can see the cheap AAA are best value in running time vs cost but Alkaline AAA is best running time.
There are may ways to rebuild these but i use two PP3s in para. I have a few metal clad ones i have gutted but watch those sharp edges but the card board ones are easy to work with and i can make the connectors for the battery using a dead PP9 and if a radio has had these cut i can also make connectors using PP9 parts and a bit of solder. You can get mains eliminators for PP9, 7s and 6s but for me it is easy to use PP3s hidden inside. I saw a PP6 mains eliminator in a old electrical shop in Port Talbot, these had no earth part for the mains and i would not trust them not because of that but they make radios hum loud and do not do the transistors any good, all 9V transistors work very well of a PP3 anyway but some used alot of power so wiring in para makes the battery pack last longer. I have an RS rechargable PP9 block somewhere but i hardly use it.
I never understood why they did eliminators for 9V transistor radios as i would have thought those batteries were cheaper than the valve HT ones. I like my radios portable as thats what they were designed for hence why i rebuild batteries.
