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!










34 comments:

  1. Thank you very much for this repair-report! For me it was very helpful, because I`m going to repair my old Wondergram.

    Best Regards from Berlin, Germany,
    Anton

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  2. you're most welcome! i'm no expert in this machine, but i'm glad that this guide has helped you!

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  3. my dad gave me one in 1958 or 59 when we were in Spain ( Barcelona) can you tell me any thing about this. thanks John Cruz

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  4. hello! what would you like to know? for starters i already listed these out in the post but i shall list them out here again:

    - it is able to play both 45rpm and 33rpm records
    - it uses the Electro-Voice 51 (ev51) stylus or equivalent (if any)
    - it uses 4 C-sized batteries

    if you have one that doesn't work it might be just a bad capacitor and you should replace all of them with modern ones. if the motor isn't running well you should give the rubber record grips a good cleaning and oil the thin shaft of the motor as well.

    i will be happy to help if you have any other questions!

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  5. Hi, my wondergram doesn't work too but the shop said the 2 transistors are blown out. I was just wondering if you know the equivalent transistor part we can use to replace. Your help will be much appreciated.

    also my email ad is jet8823jp@yahoo.co.jp

    Will wait for your response, thanks!

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    Replies
    1. i asked that same question before to the owner of the Mister Transistor website (http://www.wylie.org.uk/technology/semics/GEC/GEC.htm)

      the wondergram uses two GEC S1 transistors and one GEC-GET 114 transistor and was wondering what are the modern day equivalents to these in the event they breakdown and need to be replaced and this was his answer:

      "Peter

      I have found no data on the S1 but I know it's a germanium PNP type. I would think almost any audio-frequency OC type would work.

      regards
      Andrew"

      OC being a brand of transistors if i'm not mistaken...anyway i couldn't find any data on that either but i'm hoping that should lead you in the correct direction.

      while you can find datasheets on GET114 online (http://www.datasheetarchive.com/GET114-datasheet.html) i can't seem to find any for the S1's...so that would be the main problem.

      you are certain the problem lies with the transistors though? those things tend to last quite long and it is usually the capacitors that die first in most devices from this era.

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    2. OC is not the brand, but rather the start of the device code. e.g. OC71, OC72
      http://www.mammothelectronics.com/GT-OC71-p/100-gt-oc71.htm

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  6. I live in New York if you know a place I can buy needle and parts. thanks John

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    1. hi john you replied exactly after i replied to Anonymous!

      if you're looking for spares, the capacitors can be bought from most electronic hobby shops. i'm not sure where in New York but you'll have to google them (radio shack?)

      as for the needle (EV-51) i found mine on eBay. they tend to pop up every now and then so just keep searching. these things are rare so you must really hunt them down!

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  7. any luck on transistors or schematics????

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    1. hey, unfortunately no..this player is rare and I guess anything regarding it would be hard to find now. are you trying to restore one?

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  8. hi i am from uk and just found one of these in my uncles loft have they any value

    thanks amanda

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    Replies
    1. it depends on the condition, and whether it still works or not. go take a look on ebay, both past and present bids (if any) and you should get a good idea of the going rate nowadays.

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  9. Hi
    hope you can help have a similar problem there is noise from speaker and vinyl moves but as soon as needle is placed on record it stops. noticed capacitor at back of motor leaking so replaced but still same do the other capacitors have any relation to this problem . on your photo i see a capacitor on speaker but o mine there is none, there is one similar size as one on motor but silver not blue on the circuit board. any help appreciated

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    1. hello, from my experience there are 2 possibilities that make the motor stop when the needle is put on the record. One is that the part of the motor shaft that touches the rubber wheels is dirty and slips too much, and the other being that the batteries are put in the wrong way (happened to a few people who emailed me privately).

      If you think the shaft is clean and has a good grip then try to swap the batteries (polarity) the other way around.

      there should be a capacitor across the speaker..does it look like there used to be one soldered there before? or is it just missing? or could it be on the circuit board instead of across the speaker. you mentioned that the capacitors are of a different kind from mine...perhaps someone made a modification previously?

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  10. Hi
    thanks for that yes turned batteries round works, one more question play but sound a bit crackly . will this be a problem with speaker if so can you get replacements easily. many thanks

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  11. Hi
    forgot a bit, no there is no evidence of a capacitor on speaker no solder residue . if it is on circuit board would not know which it was. the player came from someone who had it from new and don't think any modifications have been carried out.

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    1. sorry i did not see your comment, anyway the crackling could be due to a variety of reasons as well...are you playing a mono record? because i've had better sound with mono records than with stereo ones (very loud crackling). also the speaker itself is really old and you can't expect pristine sound out of it sadly..

      i'm not sure if the player will work without the capacitor...but you can easily find a suitable one (100uF 6V) for the one at the speaker and solder it there yourself.

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  12. Hi there...
    I wrote from Brazil. Nice post!
    I got my Wondergram today...i buy online on same situation as yours.
    I opened and cleanup already. Its work, but crakling a lot. I needs a new needle and some adjustments.
    Your post will be very helpfull.
    Thanks,
    The Corsario.

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    Replies
    1. thanks for your comments! I'm glad my post would be of help to you! unfortunately the needle would be a bit hard to find right now.. I've been checking every now and then for spares but none are showing up.. good luck with getting it to work!

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  13. Thanks my friend!
    I found needles...they will cross all over the world!
    Take note:
    http://www.styli.co.nz/stylus-049.html
    http://www.surplustronics.co.nz/products/3114-stylus-electro-voice-ev51-power-point-red-lplp
    Know i looking for one Sony PS-F5 or F9 to buy...if you see some around, please advice: thigomaio@hotmail.com. Tks!
    The Corsario

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  14. Does polarity matter with the capacitors?

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    Replies
    1. yes the capacitor polarities definitely do matter and you may not have any sound if you wire them the wrong way

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  15. Hi! I search for my wondergram original or similar cartridge.Thanks!

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  16. P are you still monitoring this Re-build thread? Have a few questions.

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    1. yes, i am still active but i turned off notifications for comments due to the mass of spam messages i receive, ask away and i'll see if i can help you out! reply directly to this and i will get a notification mail

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    2. Hi, i'm italian and you article is very interesting. I bought this turntable and Initially the turntable went perfectly, but then suddenly we turned back and the disk rotates very slowly. I tried changing the batteries, but nothing has changed. Can you help me please?

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  17. Hi, I just bought a wondergram, havent got it yet but was planning on doing a bt of work on it anyway and this has been quite useful. For those who are interested I did find a schematic for it here: http://www.radiomuseum.org/r/emerson_uk_wondergram.html

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    Replies
    1. thanks for that, would be useful for those who need it :D

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  18. This comment has been removed by the author.

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  19. pladespiller vil ikke starte når tone armen trækkes ud, hvad er der galt

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  20. will not start have gone through everything.
    Is there anyone who can do this for me.
    Please contact me here
    Best regards S.

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  21. Cut some cardboard strips from a cereal pack 1/8 inch wide and clean the leaf switch along the back of the PC board. There are two places to clean as there are 3 leaves. Move the arm to put pressure between the contacts you are cleaning.There will be pressure on one pair at one end of the arms travel and on the other pair at the other end of the arms range of movement. Spray a cleaning fluid on the cardboard after you get it into the switch. You have to work from the front as there is a fourth leaf of the switch which is vertical and is in the way. It is important that you understand how the switch works before you start. There is a dimple on the vertical leaf and half of it has been filed away to leave a straight line cut. This leaf in sprung towards the others. When you swing the arm away from the player the 3 leaves are forced down towards the deck. The vertical leaf has to put its dimple cut over the top leaf to hold the three of them down. It latches them down. Then when the record is finished, the little grubscrew gives the vertical leaf a poke, and the latch is released. Have a play with the arm a few times and watch this in action. It is very clever! But its also a bit tricky if you need to adjust it. Might have to do it a few times before you succeed. I did! I dod NOT need to adjust the screw. Anyway, to clean the contacts, while the cardboard is damp with a NON RESIDUE type cleaning fluid, and the contact leaves grabbing the cardboard, move it to and fro to polish the contacts. The card strip may come out with a black stripe. Try not to bend the contacts while doing this. After I got mine going, replaced the capacitors,roughened and cleaned the drives, I now think I have a bad motor. When I short the 11 ohm resistor it goes quite a lot better but a bit slow and speed varying. I suspect the motor may have a governor at the pulley end and commutator at the terminal end. Either of these is contacts that may have tarnished. I dont yet know if I can pull the motor to bits without destroying it.

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  22. Hi, I just found one of these in my aunts attic. Motor seems to work fine but one of the wheels covered in rubber (the one to the bottom left of the player) has lost its rubber which I'm guessing would cause problems/ the records are not getting up to speed. Any ideas who I could new rubber on the wheel?

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