17 September 2011

Project "Emerson/Baird Wondergram"

i bought this thing online and waited a long time for it to ship from halfway around the world. it was a gamble because i know from the seller that the motor on the player spins but the sound doesn't work at all and it would be worthless as a record player if it didn't make any noise whatsoever!

so anyway, this is an Emerson Wondergram made in the 1960's. as you can see it is a battery powered portable record player that plays both 33rpm and 45rpm discs...a 'Wonder' for its time and weighs a 'gram' (ok not really, but see what i did there? hurhurhurhur) it comes with a holder on the top cover for a 45rpm adapter too which is pretty neat.

*EDIT* i totally forgot to mention that this player originates from the UK made by a company called Baird, but sold in the USA under the Emerson brand. the player has the Baird brand on the bottom plate that say "Baird, Made in England, A Camp Bird Product" (what is Camp Bird anyway?)

*EDIT* in case you're wondering the size of this, here's a tissue box for comparison:

when it first arrived, the motor spins but sounded like a jackhammer. when i tried to put the needle on a record, the entire player just ground to a halt. obviously the motor just didn't have the juice and was in need of some restoring.

opening it up isn't hard, just remove all the screws you see on the outer shell and you can lift the innards all out. as you can see from the pictures above, this thing was hideously dirty and dusty inside. the dampening sponges under the speaker and the motor were hardened and flaking debris each time i moved it, in short it was a real mess.

the way the motor runs the records at 33 and 45rpm is a real curious thing as it doesn't 'directly' spin the record like in a normal player. you can see the motor in the picture above and the shaft is touching one of the two rubber wheels. when the motor spins, it turns both wheels as well. the clever bit is that both wheels are set at different distances and this enables it to play records at either 33 or 45rpm.

when you put a 45rpm record that has a smaller diameter than a 33rpm, it would only touch the inner wheel that spins the record faster since the wheel is nearer the center of the record. when you put a 33rpm disc it will touch the outer wheel. since the 33rpm wheel is further from the center of the record, a 33rpm record would not touch the 45rpm wheel at all because that wheel is smaller...ingenious!

after inspecting the circuit, checking for continuity, dry solders, cracked solders, broken wires, etc etc...i spotted this in the picture below:

well there's your problem! the capacitor across the speaker is obviously blown and its guts have leaked out. it needs to be replaced.

as you can see, i have a big thumb. and also this capacitor is 100 micro farads and rated for 6 volts. my brother was kind enough to explain to me what this capacitor is for (to convert a DC signal into an AC one so that the speaker would work) and even drew a diagram out.

the entire circuit in the player only has 3 capacitors. one going to the speaker (100ufF, one on the motor (100uF) and one on the main circuit board (10uF). i decided to change all 3 to modern day equivalents and although that's not the purist way to restore antiques, it is hard to trust 40 year old electronic components to last very long nowadays (if you can find them!).

the picture below shows the difference in size of the original capacitor and its modern day equivalent. i couldn't get my hands on a 6V rated one and got a 16V one (it doesn't matter).

while i was changing the capacitors, i managed to break some wires just by moving the player around my desk. the wires were all corroded and i replaced all the wires (not a lot, about 7 all in all) with new ones.

so its out with the old and in with the new!

the solders in the picture above shows that this machine was obviously assembled by hand. i used new solder for the new wires, and resoldered all the old solders as well just in case there were dry...i figured this would ensure there were no breaks in the circuit and give the player another few decades of life.

the single speaker has the brand 'ELAC', i googled the brand and apparently it's still around today...they must have partnered with Emerson back in the day when this player was produced.

on the left side in the picture above you can see the auto stop mechanism. when the arm reaches the end of the record the mechanism will push away a metal contact, opening the circuit and stopping the player completely.

after resoldering, rewiring and replacing the capacitors, i worked on the cosmetics of the player because it was heinously dirty! a quick polish with the novus plastic polisher (previously used on the westclox alarm clock) and it gave the shell a nice sheen to it. (before and after on the left and right respectively)

ok...granted it's not much of a difference but it'll take ages to buff the scratches away, i'll leave them there for the 'rugged' look.

*EDIT* you can see the Baird brand between the two upper legs in the picture above

i managed to order a new needle online to replace the worn out one that came with the player, no prizes for guessing which is the new and old needle.

in case you're looking for the needle for this machine, it is an electro-voice 51 (ev51). it is a ceramic cartridge and has 2 sapphire tipped LP points (so more bang for your buck because its two needles in one!).

so anyway all that was left was to slap in new fresh batteries (4 x C-sized, in case you're wondering) and test it out...and it works!