The Juke-Boxes
4. The Ditchburn Mk2R Music Maker 30 Part 2
PART 2:  Karl Dawson’s  MK2R Music Maker 30 Serial Number 2594
This   Machine   first   started   its   life   as   a   MK2   16   selection   78   RPM   machine,   at   some   point   after   1955   it   was   returned   to   the   Dock Road   factory   in   Lytham   and   converted   to   a   30   play   45   RPM   machine,   the   original   mechanism   was   built   in   the   UK   under license   from   the   USA   company   Wurlitzer,   but   the   30   Play   conversion   kit   was   designed   totally   by   Ditchburn,   as   far   as   we   know Wurlitzer never made a 30 play 45 rpm mechanism. As   mentioned   in   the   last   section   of   part   1,   I   decided   that   a   strip   down   was   required   as   a   lot   of   the   parts   were   coated   in   old solidified grease and needed to be cleaned and lubricated.  First   i   started   with   the   credit   units   The   first   is   the   original   credit   unit   that   was   modified   a   credit   removal   coil   and   relays   this   unit adds   1   credit   for   every   6d   inserted   and   every   time   a   record   is   selected   a   credit   is   removed.   this   unit   also   was   modified   with     relays to switch the motor run and the amplifier mute circuits. also additional capacitors had been fitted to de-bounce the coils. All   the   capacitors   needed   replacing   as   they   were   old   type   electrolyte   caps   and   were   showing   signs   of   aging   and   failure,   also the   relays   were   replaced   as   the   contacts   were   in   bad   in   a   bad   state,   you   can   see   that   the   back   relay   that   mutes   the   amp between   plays   has   a   burnt   contact,   that   is   because   the   original   relays   were   not   rated   at   300vdc   and   the   Valve   HT   took   its   toll over time.  
Add and Deduct a Credit Unit  
Front   ( before restoration )  
Back   ( before restoration )  
Photo Ref: DB301  Courtesy of Karl Dawson.
Photo Ref: DB303  Courtesy of Karl Dawson.
Front   ( after restoration )  
Back   ( after restoration )  
Photo Ref: DB302  Courtesy of Karl Dawson.
Photo Ref: DB304  Courtesy of Karl Dawson.
All   the   mechanical   parts   were   removed   and   cleaned,   the   star   wheel   was   lubricated   using   a   fine   Graphite   powder   do   not   use   oil as   this   will   cause   dust   to   stick   to   the   shaft   and   will   prevent   the   wheel   free   running.   the   caps   were   replaced,   and   the   relays were replaced with higher rated and sealed units.  
3 plays for 1 Shilling Unit  
This   Unit   provides   3   pulses   to   the   credit   unit   above   on   insertion   of   a   shilling,   This   unit   took   a   bit   of   work   to   restore   it   uses   a GPO   uni-selector   that   has   a   wiper   contact   that   moves   1   position   for   every   pulse   on   the   step   coil   and   on   insertion   of   a   shilling   it will   step   across   the   25   positions   from   start   to   finish.   some   of   the   contacts   had   dirt   and   corrosion   on   them   so   it   took   a   bit   of work   to   clean   them,   the   unit   uses   two   capacitors,   both   these   needed   replacing,   the   first   one   acts   as   storage   for   the   coil   and the   second   capacitor   prevents   the   credit   coil   on   the   unit   above   from   dropping   out   as   it   steps   between   the   25   individual contacts, these units fit onto the side of the cabinet.
Photo Ref: DB305  Courtesy of Karl Dawson.
Photo Ref: DB306  Courtesy of Karl Dawson.
( before restoration )  
( after  restoration )  
Photo Ref: DB307  Courtesy of Karl Dawson.
The Turntable  
The   Rubber   turntable   mat   had   over   time   become   hard   and   brittle   and   lost   its   grippy   surface,   I   thought   it   was   going   to   be difficult   to   find   a   replacement,   but   i   noticed   that   the Ami   R84   mat   was   very   similar   and   thought   it      may   need   some   trimming   to fit   but   when   it   arrived   i   found   it   was   identical   in   size   to   the   original,   but   the   bottom   had   fixing   protrusions,   so   it   was   a   simple process   of   slicing   these   off   flush   with   the   surface   and   gluing   the   mat   to   the   turntable,   i   cleaned   the   platter   and   hub   chrome   with metal polish and it was as good as new.
Photo Ref: DB308  Courtesy of Karl Dawson.
Photo Ref: DB309  Courtesy of Karl Dawson.
Photo Ref: DB310  Courtesy of Karl Dawson.
Photo Ref: DB311  Courtesy of Karl Dawson.
Photo Ref: DB312  Courtesy of Karl Dawson.
The Record Stack  
The   record   stack   had   become   stiff   over   time   due   to   the   oil   and   grease   solidifying,   so   i   decided   to   strip   down   the   stack   and clean   and   polish   each   tray,   the   grease   was   difficult   to   remove   but   underneath   the   chrome   was   still   top   quality   so   only   metal polish   was   used   to   bring   back   the   shine   on   each   stack,   on   reassembly   i   used   a   few   drops   of   3in1   oil   between   each   washer and tray and also in the spring linkage. the trays were exceptionally free moving after this.
Photo Ref: DB313  Courtesy of Karl Dawson.
Photo Ref: DB314  Courtesy of Karl Dawson.
Photo Ref: DB318  Courtesy of Karl Dawson.
Photo Ref: DB319  Courtesy of Karl Dawson.
Photo Ref: DB320  Courtesy of Karl Dawson.
Photo Ref: DB321  Courtesy of Karl Dawson.
The   end   of   record   trip   switch   and   the   cam   cycle   start   switch   was   in   bad   condition,   so   replaced   the   trip   switch   with   a   new sensitive micro-switch, these switches are used in coin slots so take very little tracking pressure to activate the contacts. and the cycle start switch was replaced with a heavy duty micro switch
Photo Ref: DB322  Courtesy of Karl Dawson.
Photo Ref: DB323  Courtesy of Karl Dawson.
Photo Ref: DB325  Courtesy of Karl Dawson.
Photo Ref: DB326  Courtesy of Karl Dawson.
The Tonearm  
The Tonearm   trip   assembly   was   stripped   down   the   solidified   grease   was   removed   and   the   bearings   made   free,   and   some   light oil   was   applied,   the   supports   and   mount   were   cleaned   and   re-painted   black.   a   tag   strip   was   added   to   the   support   using   a spring clip to allow for easy servicing. and the unit reassembled and tested with the start and trip positions on the record.
Photo Ref: DB327  Courtesy of Karl Dawson.
Photo Ref: DB340  Courtesy of Karl Dawson.
Photo Ref: DB341  Courtesy of Karl Dawson.
The Final Test  
Before   putting   the   Mech   back   into   the   cabinet,   i   decided   to   first   test   the   mech   on   the   trolley,   connecting   everything   together.   it also allowed me to set up the record start and end trip positions easily. 
Photo Ref: DB333  Courtesy of Karl Dawson.
The Videos  
Thank you for watching, there’s another restoration starting soon.