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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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28th Jan 2019, 1:10 pm | #1 |
Tetrode
Join Date: Sep 2013
Location: Farnham, Surrey, UK.
Posts: 50
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EMI Emidicta
Hello all
All I have just opened up an Emidicta. Does anybody have a diagram please? It is an early one with 2 off H63 (top cap grids) a B65 and a U70. see photos. Luckily I have found some discs for it. It will be fun to get it going. |
28th Jan 2019, 4:36 pm | #2 |
Octode
Join Date: Aug 2003
Location: Welwyn Garden City, Herts. UK.
Posts: 1,906
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Re: EMI Emidicta
Interesting to see that it has a Collaro turntable motor.
I wonder if other parts of the mechanism were made by them. |
2nd Feb 2019, 10:38 am | #3 |
Nonode
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,364
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Re: EMI Emidicta
Wow, that takes me back. when I was a youngster back in the 1960s I had one of these, broken up for parts long ago. I used to rig it up with a wartime carbon mike, battery and transformer, and fed the amp output to a speaker hidden in the garden hedge. I used it shout into the mike and startle old ladies walking by. Don't try this at home folks! Cheers, Jerry.
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2nd Feb 2019, 11:09 am | #4 |
Octode
Join Date: Dec 2017
Location: Morden, Surrey, UK.
Posts: 1,552
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Re: EMI Emidicta
We used to have various bits for these - my dad worked at EMI at one time. No circuit though.
I don`t think Collaro made anything other than the geared motor, EMI had pretty comprehensive manufacturing facilities. The motor part of the Collaro assembly was the same as many standard Collaro decks, I stripped the assembly and used the coils to fix other units a couple of times. |
25th Feb 2019, 11:06 pm | #5 |
Tetrode
Join Date: Sep 2013
Location: Farnham, Surrey, UK.
Posts: 50
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Re: EMI Emidicta
I still don't have a diagram but I have got it running. I have changed some of the capacitors and it plays quietly. The turntable takes about 4.7 seconds per rev giving a surface speed (variable depending on radius of course) of about 7 ips. I expect they were aiming for 7.5 ips.
The play head consists of a single lamination about 0.5 mm thick. Unfortunately both coils are open circuit with the wires too thin and corroded to attempt a repair. However I found an old four track head and filed away one of the tracks to leave the other track laminations protruding from the rest of the head to simulate the original crude head. To my surprise it works quite well. There is a clever mechanism in the play arm that allows fine tuning of the position of the head to conform to the original tracks on the magnetic sheet record. I am encouraged to order a complete set of capacitors to see if I can fix the low volume. It will never be hi fi but I like curiosities. I need a microphone for it too as it has a six pin connector which is needed to operate a switch that flicks the arm back to the previous turn of the record with a solenoid powered ratchet. Very clever and necessary for a dictation machine. |
1st Mar 2019, 7:02 pm | #6 |
Octode
Join Date: Dec 2017
Location: Morden, Surrey, UK.
Posts: 1,552
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Re: EMI Emidicta
Gordon - I have discovered what I believe is a new Emidicta head, it has been kicking around in a draw for over 60 years but it measures O.K. continuity wise.
Yours if you want it. |
21st Jul 2019, 8:41 pm | #7 |
Tetrode
Join Date: Sep 2013
Location: Farnham, Surrey, UK.
Posts: 50
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Re: EMI Emidicta
Thanks to Barry for his spare NOS head. It works rather better than home filed quarter track that I improvised. Alignment was difficult as the gap has to be aligned to the original recordings on the discs I have and there is no decent adjustment. It is good enough to demonstrate but I still do not have a diagram and have not worked out the microphone and remote switching connections with no mic available.
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