Project "His Master's Voice Gramophone Model 102 Disassembly"

i have been noticing that most of the people stumbling upon this blog are actually looking for information about the HMV 102 gramophone i did up a few months ago...today i decided to do a short instructional on how to strip the entire thing down. (please click on the pictures to get a much bigger image!)

you will obviously need a flat head screwdriver, remove all the screws at the side and the two on the tonearm clip. remove the three screws on the tonearm base as well as having the tonearm out of the way would ensure you don't accidentally wreck it while moving the thing around. remove the circlip on the turntable and lift the whole thing off the gramophone.

while doing all this, make sure you put all the screws and loose bits into a container of some sort as 50 year old screws are somewhat quite hard to find nowadays in the event one of them drops somewhere and disappear forever.

once all the screws are..er..unscrewed, remove the whole bottom portion (i call this the motorboard) out of the 'briefcase' portion and put the 'briefcase' somewhere safe (put a cloth below as it might be pretty dirty and oily). the next step is to unscrew the four biggest screws left on the motorboard (the ones with the washers on them) and now the motor will fall (gently) out of the motorboard.

turn the motor upside down and you'll see three nuts that need to be removed. use either a small spanner or a pair of pliers and keep these in your safe place.

the bottom plate of the motor comes right off, but be careful at this point as the spring might/should have some power left uncoiled and might jump slightly if you're not careful (fingers beware).  the spring is kept inside the round container you see in the picture below, you would notice that my spring container has white tape all over it, and i'll explain why later.

the spring container can be removed by simply pulling it upwards off the center shaft. the container is kept shut by a retaining wire that is hard as hell to remove, and once removed, hard as hell to put back without accidentally ruining it (which is what i did). the last time i opened this was to install a new spring, and it looks okay so i won't be showing how to remove it in this blog post (it's a b*tch, but it can be done with lots of patience and/or cussing).

this part of the motor shown in the picture below is the governor and this is what ensures the spring doesn't uncoil all at once with a bang. how it works is that as the spring unwinds, the governor spins and the three metal weights you see would move outwards due to centrifugal force. as they move outwards, they move the disc towards the stopper (the black piece resting on the disc in the picture). the stopper restricts the distance the disc can move and the governor weights can't move any further and can't spin any faster either, thus giving you the desired speed. i realize i can't put it nicely in words so i provided a video for your better understanding.

so, now to put back everything together! starting with the spring container, if and when you manage to get the retaining wire back into the little groove that originally held it in place, it will probably be out of shape and spring out of position the moment you let go and that's where the tape comes in!

put the spring back onto its shaft. put the baseplate back on the motor. screw the nuts back onto the baseplate. put the motor back into the motorboard, and you will get to the picture below (whew!). now, to calibrate the speed of the motor so that it spins at 78rpm when the speed selector is set at..well..78rpm, you'll have to physically move the speed selector by hand as shown below. moving the speed selector to your right would make your speed selection faster, and moving it to the left would make everything slower...you'll have to do it for yourself to know what i mean.

you can check your speed by using a strobe disc with the same hertz as your power mains. as i am in singapore, this would be 60hz. turn on some lights and shine them on the disc while the turntable is spinning. if the lines at the 78rpm mark are stationary then you know you're at 78rpm! takes some trial and error but you'll eventually get there!

that's about it, i tip my hat (if i had one) to the engineers at HMV who designed this simple yet complex machine!

here's 'diamonds are a girl's best friend' by jo stafford:





(link to page 1/3 of HMV restoration)

Project "His Master's Voice Gramophone Model 102" (3/3)

restoring this gramophone took a good 3 months, although most of the time spent during that period is waiting for spare parts to arrive from overseas. i think it took around a full week of man-hours to scrub out most of the rust and fine tune the motor.

here's a picture (not well taken) of when i first got it:

the leatherette was falling apart at the corners, there was a huge mound of dust underneath the motorboard, and the motor didn't even work to begin with. i started off by spraying every metal part with WD-40 (my new best friend) to loosen the rust and scrubbed with a metal brush. the tonearm is originally chrome with a mirror finish, unfortunately corrosion has eaten away most of the chrome right down to the brass(?) piping. i did the best i could but it is far from how it is originally supposed to look like.

the motor was badly clogged with dust and congealed oil. i removed everything (gears, spring, etc) and again...cleaned with WD-40.

before:

after:

this gramophone was designed to play 78rpm records which are pretty rare nowadays. when i mean rare, i mean records with songs that i know and would like, there are hundreds and hundreds of obscure artists and songs on 78's records that i have found but dare not buy because i might not like them. i go around looking for records that are more 'popular'...but sadly those are set at a 'non-popular' price.

the old spring had issues maintaining a proper speed. it kept fluctuating between 76-79 rpm which is close enough if you think about it, but the variations in speed meant that the pitch of the song changes as well. it is kind of irritating to listen to a song that way, but thankfully the new spring solves that problem and maintains a steady 78rpm give or take a puny decimal place.

while searching online, i found an ingenious way of checking the turntable's speed with the use of a strobe disc. it is basically a circle of lines that are equally spaced apart and when the turntable is moving at 78rpm the lines would seem to be standing still. i fine tuned the motor speed selector until it registered 78rpm and left it at that.


the original soundbox that came with the gramophone turned out to be a cheap replica made in india. apparently it was extremely common with gramophones that were bought in south-east asia and were a standard issue. i looked online for an authentic soundbox and found a HMV 5b that was in need of repair and i had it shipped over. when it arrived, it was missing a rubber connector and had a hole in the diaphragm that affected the sound output.


i bought a rubber connector and a new diaphragm, but the 'new' diaphragm came with a hole as well and i got a refund for it. unfortunately that still left me with a leaky diaphragm and i couldn't find any new ones online (at least for now).

i ended up gluing some aluminium foil over the hole which seems to be a good fix. it won't sound 100% as good but it was much better than leaving the hole there for all the sound to leak out of.

i use modern needles bought from a guy in the US to play my records. although i do have some old needles left over from the original owner of the gramophone, i try not to use these as i trust the modern needles would do less wear and tear on the records, but i did manage to buy an original needle tin just for the sake of completing the collection!

needle tins are a collector's item as they come in thousands of designs and varieties. some claim that their needles are able to play hundreds of records before needing to be replaced, but modern science discovered that each needle is only good for one, at the most two, plays before a new needle is needed otherwise the worn out tip would gouge out the grooves of a record. this tin that i have states that each needle is good for 20 plays which is a lie! sure it'll play for 20 plays, but the record would sound like crap after awhile when the grooves are all gone. rare needle tins have sold for more than 100++ USD, this one that i have is a pretty common one but could still be worth something in the future so i'll be holding on to it for some time.

well the awesome thing now is that the gramophone works...it might not sound as good as it is supposed to sound but it is good enough for me. maybe one day i'd come across someone who is selling the diaphragm and i'll be able to hear the songs like how they're supposed to be, until then i'll be happy with what i have!

and in case you didn't know, this is a portable gramophone that folds up nicely into a suitcase to carry around.

and finally here's a video of it in operation, playing sundown boogie by bill haley and his comets.

(link to page 2/3)

Project "His Master's Voice Gramophone Model 102" (2/3)

the gramophone mainspring FINALLY arrived in the mail from the netherlands. i ordered it before christmas and it took nearly 3 weeks to arrive. must have took so long because of all the backlog of gifts and crapola the mail people must clear...

anyway so it arrived and i unpacked it, and it looked harmless enough...just a coil of metal, waiting to be crammed into a small container like so:

i removed the cableties and slowly removed the metal wire holding the spring together, and when i remembered: "hey, don't coiled springs have a lot of stored power?", the spring exploded outwards in 360 degrees. i got a nice mark on my arm as a reminder not to be stupid next time.

took me nearly 30 minutes to cram the new spring into the container, whereas the old spring took me only 5...all i can say is that this new spring is definitely able to store more force than the old one.

so there, it's done...i finally managed to fix this antique, i will take a video of it in action and post it up soon.

(link to page 1/3)

(link to page 3/3)

Project "His Master's Voice Gramophone Model 102" (1/3)

i obtained this gramophone from my girlfriend's family a few months ago. i do not own it, they just lent it to me on a long term loan due to my fascination with old stuff. i decided to clean it up and restore it as well as i can. i did take a few pictures before starting and it was in a really bad state.

i removed the soundbox from the tonearm as it was rusted beyond repair.

this has definitely seen better days.

the motorboard housing, with every metal part rusted and every corner/hole clogged with dust

the spring motor, badly rusted and congealed grease

the round object at the end of the arm that is covered in rust is the soundbox, which is the means and ways of how the gramophone produces sound in the first place...and it...is...an absolute write off...

work is still in progress on this machine, which i have been told by an online forum that it was produced in 1954, which makes this gramophone nearly 60 years old. so far it refuses to stay fixed, with some other part failing once one other part has been fixed, but i will be very satisfied once it is restored to a respectable working order.

(link to page 2/3)