Saturday, August 31, 2019

Spotting a silver Sterling

At least, that's what it looks like.

When watching the movie "Kiss and Make-Up", the secretary in the very swanky beautician's office uses a typewriter that seems to match the overall decor. The machine is light in colour, definitely not black.

A few moments later, the typewriter is shown better. As Annie looks up, the machine fairly gleams - this is a metallic shine and not a coloured lacquer. The top-cover and the panel in the sides also clearly confirm this to be a Corona typewriter, a so-called 'flat-top' model.

As is written on e.g. the Corona page at Machines of Loving Grace, in 1934 a small series of actual sterling silver typewriters were made to promote the updated 'Sterling' model. Seeing this machine shine, it seems likely that this is one of those limited-edition typewriters with a housing of actual silver.

A shiny silver typewriter fits right in the general decor, so it may have been chosen by the studio - it may also have been a promotional  'product placement' by Smith-Corona. When the film was made, these silver promotional models would have been brand-new, just about to appear in showcases in a select few shops.

However the brand name is nowhere shown, even in this view of the back of the machine any lettering seems to have been removed. So it is perhaps more likely to have been the studio's choice. (Not sure about the silver Corona's, but regular machines have the name printed on that back panel.  Have never myself seen an actual silver typewriter; these were rare then and are even rarer now.)

The movie itself is of course a bit dated and very much a 'pre-code' production. Light comedy and visual escapism that is lightyears removed from actual reality - let's just say that the film was not made for its storyline.

It has an 'extravagant' cast to match the film's theme, with Cary Grant as the male lead. And they used an extravagant typewriter prop too.

In any case, a pretty rare machine to spot!
(Picture of an actual existing sterling silver typewriter here.)

Wednesday, August 21, 2019

AvoMinor 67004-442

From the company that invented the multi-meter, a small and simpler instrument. The 'AvoMinor' was introduced in 1933, upgraded in '35 with a socket inside the Ohms adjuster knob. (As with every little niche, there is quite a lot of information available online. Especially informative were the pages at Richards Radios.)

When purchased a while ago, the case looked a bit tired and the instrument didn't work.

Luckily the fault was repairable and the case cleaned up nicely. (Again; experience with typewriter cases restoration comes in handy.)

With newly made leads, the fixed instrument is again usable. Even though quite limited in function when compared to modern or even the contemporary regular Avo meters, it is good enough for most of my simple measurement needs.

The back of the instrument screws off, the cardboard battery compartment can then also be taken out. The battery leads were already broken, otherwise these will need un- and re-soldering. A quick inspection showed that fortunately the coil movement was still fine. With another meter, the various parts were inspected and tested.

This is very 'mechanical' and visible electrics, before packaged components were used. With the aid of the explanation and diagram at Richards Radios, the only actual fault was found to be the top-right coil being open-circuit.

This coil could then be taken out by unscrewing its 6BA bolt and nut and unsoldering the leads. 

Then unpacking the coil to find the fault, it turned out that luckily it was a case of lead-in wire having come loose from the coil wire proper. This is often the cause of old coils being open-circuit, rather than breaks somewhere deep inside the wound coil. The thicker lead-in wire was originally merely twisted with the coil wire, now repaired by soldering and again wrapped in paper-tape.

Battery contacts soldered again with the battery-well in place and a regular 1.5V AA battery provided with some padding or sabot then fits well enough inside the compartment.

Re-assembled and functional again, with the original instruction booklet. The serial number of the instrument indicates manufacture in April of 1942. It survived very well, the dial crisp and clean and no damage to the bakelite housing either.

The contact bushes are (of course) an odd Imperial size, they're 1/8" so a little over 3mm diameter. Even though this is an unusual size, a batch of 3mm banana-plugs were sourced. With some modern flexible litz wire and some shoelaces, look-alike reproduction leads were mocked-up. They turned out too large diameter when compared to originals - but they work and don't look too much out of place.

Added some 3mm alligator-clips, and the meter is in use - here showing that this lantern-battery is quite tired, nearly exhausted.

A nice vintage and very usable instrument again. And in reality quite complex enough, for use by a mainly-mechanical user too :)