An Un-named Portable Gramophone…
with a ‘Universal’ mains Electric Motor.
The whole point of the old sort of
‘Portable Gramophone’ is of course, that you can take it anywhere with you, and
play it without an electricity supply: at the sea-side, on a picnic in the
country &c. Indeed, these machines are often described as ‘picnic
gramophones’. They were powered by spring-driven motors, which you wound up
with a handle, and worked on entirely acoustic (or ‘mechanical’) principles.
Our American cousins describe them as ‘hand-crank portable phonographs’, while
we usually call them ‘wind-up portable gramophones’. They were made for many
decades – roughly the 1910s to the 1960s – and I scarcely need to say any more,
because you all know what they are. Millions of them were manufactured, and
hundreds of thousands still survive. They have served as the introduction for
many of us 78 rpm record fans, when, as kids, we were given one by an aunt or
grandparent, along with the ‘old records’ that went with it.
I don’t actually collect gramophones;
although there has been an alarming tendency over the last 2 or 3 years to
begin doing so. Over the last weekend, I attended the annual ‘get-together’ of
the City of
But what arrested my attention is that
this machine had an electric motor! So it was really a ‘portable gramophone’
that you could just carry around from room to room in your house, and then plug
it into a wall socket so that it would work. As the auctioneer remarked, there
just had to be a portable gramophone of this sort, since in most things there
is a ‘
But no matter; it is no longer 1930: it
is 2009 and we have an electric portable gramophone. Will it work? Well, the
first step was to examine the motor to see if it was still in good condition.
It is extremely dangerous of course, just to plug in some antique piece of
electrical equipment that has possibly lain unused for many years or even
decades. After dismantling the thing, and finding it promising inside, it
belatedly occurred to me to make a photographic record. This I then did, though
it only depicts putting it back together. Still, this is usually harder than
taking anything apart, so…
Here are the parts of the motor. It was
made by the exalted firm of Garrard, and bears no model number: the base plate
merely states that it is the Garrard ‘Electric Motor’ and so must be quite an
early venture on their part? Of course, I had cleaned all the components after
dismantling them – before that they were rather dowdy. Observe the bright
nickel plating on the base plate (centre foreground), which would normally
never be seen! So why plate it? Possibly to impress manufacturers of
gramophones at Trade Shows, who might then incorporate Garrard motors into
their products? I believe that the great
The motor is upside down in this shot.
One excellent design feature is that the motor can be dismantled for overhaul
without having to dismount the governor. The governor is the shaft on the upper
right which has the worm gear and the three balls screwed to springs. It is
suspended between (phosphor bronze?) bearings bushes that have their holes
slightly offset from their centres. This means that you can adjust the degree
of ‘mesh’ between the worm gear and the gear on the main drive spindle (which
is not present in the picture), for optimum performance. Too close a mesh puts
excessive load on the motor, while too little mesh might cause the worm to occasionally skip a tooth on the main gear,
which will soon result in catastrophic wear on the worm, main gear, or even
both. This governor was perfectly adjusted already, and so was left well alone,
apart from cleaning the rather ‘gooky’ oil from the ends and the sliding flange
& then re-oiling them.
Here is the motor. You will see from its
plate that it runs on either AC or DC and requires 40 to 50 volts. If the
voltage is AC, the frequency may be between 25 and 60 Hz, or ‘Cycles per
Second’, as they were known at the time. Actually, ‘Cycles per Second’, or
‘cps’ is an absolute measure (unlike Volts, Amps, Ohms, Watts, Farads, Henrys
&c.) and so did not really need to be named after a physicist, however
distinguished: but the term Hertz came into use for this quite a long time ago,
presumably in Germany, and has since been adopted universally. A mile is a
fixed distance, and an hour is a fixed period of time; so it would be curious
if ‘Miles per hour’ were to be termed say ‘Stirlings’, after Sir Stirling Moss.
But we’re stuck with Hertz, and I admit I am quibbling here, if not actually
baying at the moon. 8^) But more to the
point: observe the thick paint or enamel of the top section of this motor!
Marvel at the luxuriant nickel plating of the lower housing – which shows up
better in later shots. This is no doubt a quality product. The large lug on the
left is for the flexible suspension of the motor.
Here are the few remaining components,
which we will now quickly put back together. Incidentally, this motor must have
first been assembled by a man (or a woman of course) called S…… because they
had written their name in pencil on the (unplated) top of the base plate. I now
wish I had written it down, because it wore away during the cleaning process,
and I can’t exactly remember it… it would be agreeable to preserve their name
for posterity. About 35 years ago I opened up a very early Grundig tape
recorder, a 500-L or a 700-L, I forget which, and found the name Glöckner
inscribed under the top plate, and so record that totally irrelevant fact here.
Still, it is rather disquieting that I can remember the name of a person who
assembled a tape recorder 35 years afterwards after I saw it, but not that of the
person who built up this motor and which I read only a few hours ago! Memo: Can this be the onset of some sort of
chronic mental decline? Whoever they were, they certainly did a superb job
is setting up the governor.
The first assembly to be replaced is that
which controls the tension of the belt. As you see, it consists of a pivoted
L-shaped arm, with a round rubber buffer at the far end. This bears on a
projection on the top housing of the motor. The other end, via a spring,
connects with a threaded rod. A nut on the far side of the lug which is part of
the main bearing boss allows the tension of the belt to be adjusted. The
required tension turned out to be very low.
Next, the main shaft is inserted. This
meshes with the worm. It is of course driven from the top pulley, which is
underneath the turntable, and so rotates the governor assembly. Note the ball
bearing embedded in the bottom of the shaft. This rests in the housing which
can be seen in the bottom plate of the motor in the next shot.
The bottom plate is now replaced. The
assembly seen at the upper left of this image is the lever which limits the
travel of the sliding flange of the governor. The screw and lock-nut at its
upper extremity engages with a lever on the top plate of the record deck (which
you haven’t seen yet); and this has a lever for controlling the speed of
rotation. It does this by adjusting the spring-loaded arm, which terminates at
its lower end, with a felt pad which limits the travel of the governor flange.
It is important to keep this pad flexible and oiled, so that the least possible
friction occurs between it, and the governor flange.
Before re-attaching the motor to the main
assembly, we checked out the bearings. The bottom one was the easiest to get
at, so we carefully unscrewed the three screws that held it in place. Previous
experience prepared us for the fall of many tiny ball bearings! However, the
bearing proved to be rather simple. It was a plain bearing, with one ball at
the bottom of the shaft resting on a small phosphor bronze disc. A felt pad,
seen here, was obviously meant to be soaked in grease or some similar lubricant
– but no vestige of it remained…
So we simply removed the felt pad,
cleaned up the bearing, and replaced the pad, well soaking it in oil – which
would do ‘for the time being’. We have a very short attention span, and any
project which occupies more than a few hours tends to get abandoned, I’m sorry
to say! We could not do the same for the top bearing, which presumably was the
same, as the grub screw in the pulley was reluctant to turn more than half a
revolution even after being soaked in oil for a couple of hours. So we
contended ourselves with dribbling oil into it, which was eagerly taken up;
eventually a thin film of oil came out of the bottom of the bearing housing.
Honour thus being satisfied, we concluded that both motor bearings were
sufficiently lubricated. We did not remove the brushes from the motor in order
to tinker with them: we assumed they were probably OK, which proved to be the
case.
The motor was now attached to its
vertical shaft. There are three spacing washers at the top of it. Then there is
the suspension lug which is part of the upper motor casing. The ‘bearings’ in
this lug are two flanged bushes, probably of ebonite, inserted at each end of
the motor lug. No attempt was made to remove these in order to clean them. It
was suspected they might break while being extracted, so they were cleaned in situ. Below the motor lug can be seen
a large nickel plated bush. These three components are mounted on a removable
shaft which is held in place by a clip secured by a screw, as seen below.
In this shot, the whole device has been
turned upside down. Below the knurled end of the motor mounting shaft, a groove
has been machined, and the clip, secured by the screw, engages in this groove.
This excellent design feature means that the motor – should it require
replacement – can easily be detached from the main assembly. Also of course, it
allows the motor lateral movement to allow for any stiffness or irregularity in
the belt.
It’s now time to connect up the motor to
the power supply. These shots were made during trials before final assembly.
The bakelite moulding you see here was originally a switch, operated by a lever
on the motor board (which you haven’t seen yet!) I decided not to use this
switch, as the contact points on it were very corroded and really not
acceptable today. The forked brass strip and the screw to its left constituted
the switch. However, the bakelite moulding still served admirably as a
‘connecting block’, and I had no hesitation in using it as such.
Here then, is the now-redundant switch in
use as a connecting block. The bakelite screw terminals cover up all the bare
metal, so the thing is really not very dangerous at all. The wires of this
venerable piece of equipment were in very good condition even after nearly 80
years, so did not need replacing. The wires from the motor are self-evident;
but what about the ‘Power Supply Unit’ of this device? What was it, and what
shape was it in? Was it even usable at all?
This is the outer panel of the ‘Power
Supply’. There are two ‘selector screws’. The one on the left has three
positions. 1. DC; 2. AC 25 Cycles; 3. AC 50 Cycles. The one on the right
selects the Voltage: 100, 110, 120, 200, 210, 220, 230, 240, 250. The two metal
pins with slits are the terminals through which the power enters. But what does
this bewildering range of Direct Current, Alternating Current at 25 Cycles and
50 Cycles mean? There isn’t space here to go into it in any detail. Briefly,
nowadays we are used to our electricity supply being 240 Volts AC at 50 Hz. And
this is the case virtually everywhere in the
This is the back of that bakelite panel
in the previous shot. It’s protected by an aluminium guard, because there were
dangerous voltages inside. Also, it is heavily perforated to allow the heat to
escape, because getting 110 volts DC – let alone 240 volts AC – down to the 50
or so volts the motor needed, was a wasteful process that involved the
generation of much heat. Let’s look inside this thing…
Egad! We have er… seven layers of sheet
mica insulation, over which are wound varying lengths of resistance wire.
According to which screw is in which hole in the front panel, the right amount
of resistance is brought into circuit to give the right voltage to drive that
lovely little motor we’ve been raving about. The white straight things you see
are the opposite of modern flexible insulation. They are small rigid ceramic
tubes, threaded over the bare wires to insulate them from each other. One might
almost call this a ‘Frankenstein’ sort of contrivance! On no account are
unqualified people to meddle or tamper with this sort of ancient device. I
almost never get ‘uppity’ on my website, but I am going to do so now, for
safety’s sake. I have held an Amateur Radio Licence for the best part of 30
years, and this qualifies me to design, construct, adjust and operate radio
transmitters on a very wide range of frequencies, using power up to several
hundred watts. Such power may involve the use of 1500 volts or even more.
Voltages of this magnitude are extremely dangerous. Indeed, even the 240 volts
of our domestic mains supply can kill you at the drop of a hat – so do me a
favour, and don’t get involved with it, OK?
>8^(
Nothing like the above ‘mains dropping’
set-up would be allowed in domestic equipment today; and I actually agree with
that! Still, it does work, and so…
Here is the motor, fully re-assembled and
raring to go. It must surely be one of the earliest belt-drive turntables? The
belt, by the way, is a woven, canvas-like material, and the maker’s name –
Tilton – is stamped on it.
It is now reunited with its ‘motor
board’. The ‘Start – Stop’ feature has been disabled by us as you will recall,
because of arcing on the switch contacts; but the speed control at the right is
still operative. Its standard central setting is 80 rpm rather than 78; this
suggests that he whole shebang was dedicated to
The unit is now restored to its case. The
‘power supply’ mounts on the inside of a rectangular hole on the rear right of
the case, but I haven’t got around to fixing it there yet, so it still stands
separate at this time.
Finally, here again is the image which
began this inordinately tedious web-page: the machine actually works! It’s seen
here playing a red Parlophone by the Parlophone Syncopators, a.k.a. the OKeh
Syncopators directed by Harry Reser. Who actually
made this machine is unknown. It’s quite big for a ‘black portable’; but
then it would have to be, in order to accommodate a 12” turntable. There can’t
be many portable gramophones with 12” turntables to start with; and far less
still, those which were perversely equipped with electric motors, even if they
were capable of running off practically anything between 100 volts DC and 250
volts AC. The mind boggles; but strange gramophones keep on coming out of the
wall… thank heavens!
After I had written the above it was 3:00
a.m! There still remained some things to do, so we had another go at it a few
days later.
To clean up the cabinet was next, so out came the motor. We disconnected the lid stay. The lid hinge was dowdy & the screws were rusty, but we left that alone. The sound-box is rather interesting; more on that later.
Removing the tone arm & the actual
motor board revealed the horn. The round tube that fits – a bit loosely,
actually – into the base of the tone arm becomes of square section when it gets
inside the horn mouth. It then curves round with the same width, while its
height gradually increases. The sound is released & travels back through
the outer horn. What compromise – if any – has been made in order to fit the
horn into the available space I don’t know, and freely admit I know nothing of
acoustic horn systems.
Oddly, there are no less than seventeen
holes, or incipient holes, that secure the tone arm base onto the motor board!
It is difficult to understand why this should be, as the tone arm has no stop –
it can rotate 360° in its base. In other words, the three holes required
can be anywhere. One at the front and two at the back would be the obvious way
forward, not seventeen. 8^)
Here is the underside of the tone arm base. It is threaded, and it is presumed that the outlet is in the form of a flange which screws in. No attempt was made to dismantle it; it already rotated fairly freely, and oiling it from the top made it freer still.
At first we were puzzled by two holes underneath the back section of the tone arm. They were tapped, presumably 4 BA. It then dawned on us that they were the attachment for an arm that would operate the auto-stop mechanism, which had been removed for some reason.
In order to fit the mains dropping device, it was necessary to remove the horn, which was fixed in the corner of the box by four screws. On the side of the box, the above pencil inscription was revealed. S12 8? Or is the ‘S’ a monogram?
Now reassembly could begin. The mains dropper unit was fixed in place using, I reluctantly admit, modern ¾″ chipboard screws. These are too long; so washers were improvised from plastic IKEA nail-on feet, sorry! (Out of sight, out of mind…) Then the horn could be replaced.
The bakelite moulding (which was the switch, but is now simply used as a connecting block) was replaced. It is secured by two short 4BA bolts from the other side. Incidentally, either when the thing was first assembled, or more likely later when it was being worked on, one of the two wires from the motor had been trapped between the motor and the base plate. The top wire is supposed to be above the base plate, and the lower wire below it, as you see here. As found, both were either below it or above it – I forget which – and so the insulation of one wire had been badly pinched. I think this push-on insulation was called ‘systoflex’; but in any event, it had not worn through, a tribute to its durability!
So: the ‘motor board’… no, that can’t be right! The motor board is the wooden one, right? So what shall we call this metal thing? Ah – I have it: the motor chassis, of course! This is now ready for screwing down. At this point, it’s worth mentioning the auto-stop mechanism. I did not dismantle & clean it, since we’re not using the electric switch. However, the mechanism works perfectly in any case. You ‘prime’ the mechanism with the lever at the left. When the sound-box traverses the run-off groove, the (missing) actuator on the underside of the tone arm pushes against the bush ‘S’. It only needs to travel ⅛″ and the brake mechanism trips. Excellent stuff! There is also an interesting linkage ‘L’, which I have temporarily installed upside down for this shot. This is a strip of metal with a spring clip at each end to hold it in place over two short bushes. The bushes are part of the shorter arms. To remove the linkage, you just prise up the clip with a screwdriver and it disengages & can be swung out of the way. This makes it easier to change the belt on this machine; or perhaps Garrard were in the habit of using such linkages anyway? In any case, it is an elegant system.
Here is the adjustment panel of the mains dropper unit in its proper place.
…and here is the machine merrily playing a record. Mind you, I don’t want to pretend that the whole thing works properly – not a bit of it! When you first switch it on – or rather plug it in, because there is no switch! – the motor is rather reluctant to start, so you have to give it a few helping pushes. Then it needs to ‘warm up’, so you leave it running for a few minutes. After all, when you’re nearly 80 years old, anybody needs to warm up, correct? But when it is warmed up, I’m happy to tell you that the 80 rpm setting on the speed control is indeed almost exactly 80 rpm to this day. True, when you play a record, it drops to 79 rpm, but what’s a single rpm between friends? 8^) By the way, there is a record-carrying flap in the lid of the machine, to be clearly seen in this shot. It is made out of stained & polished wood, but curiously, is concave & so is thinner at the bottom than at the top – not a terribly good idea? Notice also that the left-hand retaining hook is bent. I took pliers and straightened it several days ago – but it’s bent again! More on this below…
As we said, the anonymous sound-box is of some interest, though whether it belongs to the tone arm is unknown. The stylus bar suspension seems to be a piece of spring steel fastened to the very substantial gasket-securing ring by the upper pair of bolts. The stylus bar is connected to this spring suspension by the lower pair of bolts. Unfortunately the rear connecting tube (pot metal) is broken, and the sound box was fixed in place with plastic tape when we acquired the machine. This is not a problem at all, as one might easily hazard £5 on a slightly damaged sound-box of commendable design, even were it not attached to a rather interesting gramophone that was ‘thrown in’ with it for the fiver!
There is another problem with the design of this machine, namely the geometry of the arm and turntable, as you can plainly see above. Generally speaking, we want our needle (and indeed our stylus on modern machines) to come about half an inch in front of the turntable spindle. This arm, alas, comes nearly an inch behind it. This is not so good; but overall, it remains a very interesting machine! Lastly (for the time being)…
…you will see that the gap between the turntable and its chassis is quite big – about ⅝″. This is, of course, because the turntable has risen up over the years, the rubber suspension bushes having perished & so become thin. It is also the reason that the left-hand lid-tray retaining hook bent again after I had straightened it – it’s fouling the turntable when you close the lid. Also, there is some perceptible noise while the motor is running.
The answer to this is a visit to B&Q to buy some tap-washers, to replace these bushes. Also, it would be rather interesting to do some electrical measurements. Possibly the reluctance of the motor to start is due to insufficient voltage? Some of those resistances wound on the mica strips you saw long ago got overheated some time in the past, and their resistance has increased? I don’t know much about resistance wire, but ordinary carbon resistors, if overheated, usually increase in value. So we will need to measure the voltage at the motor terminals, to see if it really is between 40 & 50 volts. Also, measuring the current will be useful. As you know, amps x volts = watts (should these units have capital letters?) so that will tell us the power consumed by the motor, while it’s playing a record of course. Also, the input power from the mains would be useful, because we can then calculate the efficiency of the system. We predict that it will be low, because as was pointed out, much power is wasted as heat to get 240 volts down to 40 or 50. When the gramophone was reassembled, it was left to run for an hour or so. We wanted to find out how hot it would get. The rear right of the motor board, which is directly above the mains dropper assembly did get quite warm, or even mildly hot; but I don’t think there would be much chance of this machine transforming itself into a sort of Flame-Phone * …
More later!
* The Flame-Phone was a gramophone, from the 1920s I think, in which the output from the sound-box was used to modulate an array of gas flames, and so produce amplification of the sound. You might think I’m joking, but I’m not; there really was such a machine. It is obviously very obscure as I cannot find it on Google; but just because it isn’t on Google doesn’t mean that it didn’t exist, honest!
Page written 14/15th September 2009.
Expanded 22nd September
2008.