The Sky Countess

I'm sure that if I'd been born in 1846 rather than 1946, I'd have been happy to lead the life of an itinerant tinker.  I can imagine myself  in a horse-drawn caravan with a small living area and the rest of the van converted into a mobile workshop.  I'd have travelled the length and breadth of Victorian England mending kettles, teapots and fire-irons, and sharpening kitchen utensils and scythes.  Bliss. 

As it was, when my wife and I were newly-wed and set up house together, she was canny enough to buy me an 8' x 6' garden shed for my next birthday.  That was nearly 40 years ago, and for all that time my shed has been the equivalent of the back half of my ethereal caravan.  Few thing in life give me greater pleasure than 'going down to my shed for a tinker'.  'Sheditation', my wife calls it.

I always enjoy the 'limbo' week between Christmas and New Year.  The Christmas visitors have gone home, peace and quiet have returned and there's time to do a bit of tinkering.  But the trouble with tinkering is that you can't rustle it up out of thin air; you have to have something to tinker with, so I'm always on the look-out for bits of what most people would call junk to exercise my tinkering skills on.  And so it was that just before Christmas (2009) I came across an old 1950s-vintage portable radio (with valves) in one of the local house-clearance shops.  I didn't buy it straight away; I looked it over and managed to remove its front panel so that I could have a good gander at the works; it appeared to be complete and undamaged.  It was an Ever-Ready 'Sky Countess'.

In between the Christmas festivities I managed to find some time to rummage about on the internet for information about the 'Sky Countess'.  It sold in 1958 for the princely sum of eleven-and-a-half guineas (£12.1s.6d, or roughly £12.08 in this new-fangled metric money).  I reckon that's equivalent to about £240 today; it's remarkable what people would pay in those days for the privilege and novelty of owning a truly portable radio that wasn't much bigger (or heavier) than a couple of house bricks.  The 'Countess' was one of the last-of-the-line of valve portables.  Within a few years the beautiful valve had been usurped by the unglamorous transistor, and radios the size of fag packets, with tinny sound to match, became the norm.  

Being a relatively late portable-valver, the 'Countess' incorporated a few refinements that hadn't been common in earlier valve portables.  Notably amongst these were the use of a ferrite rod (rather than a frame) aerial, and construction based on a printed-circuit board rather than an aluminium chassis with tag-strips.  The set's four valves are the ubiquitous '96' series, which were commonplace in portable-valvers for many years before 1958.  For the technically minded (and I include this bit because I know it will send shivers of delight down the spines of those who are familiar with these things; if it leaves you stone cold and bored (sad old you!) just skip down to the end of this paragraph) they are DK96 (heptode frequency-changer), DF96 (pentode I.F. amplifier), DAF96 (diode-pentode detector and 1st A.F. amplifier) and DL96 (pentode audio output).  These valves were designed with power economy in mind in order to extend the life of the relatively expensive batteries. The whole receiver consumes just over a watt, or roughly one-third of the standby power drawn by my 21st-century PVR box.

You've already guessed that by now I was hooked.  On the Monday after Christmas, with my internet research complete, I strolled as nonchalantly as I could into the house-clearance shop and to my delight the set was still there (why are these beautiful things not snapped up the moment they appear?)  I feigned only moderate interest and managed to get a price reduction on the grounds that the shop appeared to be having some sort of winter sale.  It actually cost me numerically less than someone paid for it in 1958 and I came out clutching my new 'Countess' with a big smile on my face.

The construction of a PP3 is exactly like the 'layer' battery above.  It contains 6 layers, each of 1.5 volts, to give 9 volts.  The individual layers in a PP3 are a bit smaller than those in the original H.T. battery, but work well enough.

Put your hand up if you can see beauty in this!   Call me a nerd if you will, but I've always held the view that beauty comes (or at least can come - very powerfully) from functionality.  A good example of this is the steam railway locomotive - most people consider these to be beautiful; why?  Because they have no frills; everything you see is serving a purpose and every component contributes to a whole that is much greater than the sum of the individual parts.  When you look at a radio set in the flesh you always see ornamentation to some extent: the nice brown rexine that covers the case, the knobs with the gold centres, the handle with the plated fasteners.  But when you look at a circuit diagram you see the device stripped of all its ornamentation; you see only the stark functionality of it.  You can't tell from the circuit diagram that the set has gold knobs or that it lives in a brown case.  The only information it gives you is precisely how the thing works; therein lies the beauty of it!

Enough philosophising.  So which components would give grief if they went wrong?  Well, I can see two likely candidates: firstly C25, the big electrolytic capacitor that sits between H.T.+ and L.T.- (to the right of the loudspeaker on the circuit diagram).  The old one has been there for 50 years, probably hasn't seen volts in most of that time, and now it's about to see ninety of them with nothing to limit the current other than the internal resistance of ten PP3 batteries!  Out with it, and in with a new one!  Second candidate is C24, which couples the anode of the first audio stage to the grid of the output valve.  It's less likely to be faulty than the electrolytic, but if it does go short-circuit it'll probably write off the output valve, and where do you get a new DL96 these days?  Out with it, and in with a new one!  And unless I start to get paranoid, those are the only components I can see that could cause instant disaster when the power is applied.

When I was a college student studying electronics back in the sixties, I had a colleague who struggled a bit when it came to mending faults.  However, he soon came to the conclusion that once you'd got the covers off it was always a good idea to look for something black, broken, smoking or disconnected before you started delving into the circuitry - and this wasn't such a bad idea; many faults can be diagnosed just by looking.  So let's have a look at the 'Countess':

The first point of note is that there's a fair bit of corrosion on the body of the wavechange switch and indeed this and the volume control were both quite difficult to turn.  It was also clear that the three bolts holding the tuning capacitor to the chassis (one of these is just visible below the ferrite rod) were loose.  Further visual investigation confirmed that these bolts are the only means of earthing the tuning capacitor body, so it was essential to tighten them.  So all three controls needed attention, which meant removing the chassis from the front panel.  

The first job was to pull off the knobs, and after 50 years of staying put, they really didn't want to know.  It needed a combination of steady pull and side-to-side wiggle, and with care and patience the knobs eventually came free.  The chassis is fixed to the wooden front panel by extended nuts on the wavechange switch and volume control; these were easily undone and the panel and chassis could be parted sufficiently to get to the offending items.  With the chassis and panel parted, the tuning capacitor screws could be tightened. 

The wavechange switch was cleaned up with a small fibre brush, and its shaft and indexing springs lubricated with a few drops of clock oil.  The contacts themselves looked reasonably clean but were given a squirt of Servisol switch cleaner to be on the safe side.  Ideally the volume control potentiometer should have been removed entirely, dismantled and cleaned, but its connections were awkward to get at so I decided in the first instance just to lubricate the shaft (another drop of clock oil) and to squirt switch cleaner into the body of the pot.  In the event this proved to be sufficient as there has been no sign of any problem with it.  The rotor of the tuning capacitor is earthed by two strips of spring wire (visible in the photo) which bear against the rotating shaft.  These were cleaned with a cotton bud soaked in switch cleaner; the front spring was particularly claggy where it had been contaminated by grease from the shaft bearing.

I removed the valves, carefully (and one at a time!) and checked the continuity of the filaments - fortunately all were O.K.   Had they not been, I would have been faced with the prospect (and expense) of trying to source replacement valves, and this possible problem was my greatest concern when I purchased the set.

The battery plugs (3-pin for the H.T.- one is just an indexing pin - and 2-pin for the L.T.) both needed remaking to the cables as there were significant lengths of uninsulated wire protruding from the back of the plugs.

It was now possible to reassemble everything, connect up the batteries and give it all a try.  I plugged in the L.T. first and then the H.T. and was immediately rewarded with radio-like noises from the loudspeaker.  In fact it all worked remarkably well; the receiver is sensitive and selective and there is plenty of reserve audio gain for weak stations.  Most surprising of all is the audio quality.  The combination of a relatively large loudspeaker and a solid, large cabinet gives an audio quality rarely heard from a portable radio these days.

With the technical stuff sorted, I could put the works to one side and turn my attention to the looks of the thing.  The case was extremely grubby and some of the joins in the rexine covering had come unglued at the edges and seams.  Detergent, a small scrubbing brush, elbow grease and patience dealt with the former problem, and when it was all dry, impact adhesive did the latter.  A light application of furniture polish restored the rexine's satin shine. 

The batteries are kept in place by wooden battens glued to the bottom of the case (which is made from hardboard!)   In 1958 most wood glues were still made from the boiled bones of dead horses and I suspect the horses used by Ever-Ready must have been seriously under-nourished for years before their demise; the battens for the H.T. battery were missing entirely and those for the L.T. battery were loose.  I'm confident that the new battens, glued in with PVA, will easily survive another half-century.

Right, then.  In a week or two I'll be ready for another tinker.  There's a solar-powered hot-air engine in the back of the garage.  It doesn't seem to work very well . . . . .