Collaro RC457 record deck from 1958

[N_Cook]

In Philco A3762, i have the schematic but mechanical problems
Would there have been a rubber tyre on the rim of the left hand drive
pulley , shown in this pic , half way down
http://www.lencoheaven.net/forum/index.php?topic=11426.0
right hand one is for PTO use.
Perhaps red rubber like the platter mat (I remember replacing a
perished/hard/split BeoGram drive tyre that was red)
The images shown above have a hint of a circular mark set inside of the
rim proper, both sides , as though something was fitted there at one
time. This one has the same marks but no sign of any tyre inside
(someone had been inside under the platter so perhaps they disposed off
remains)
Dated from to 1958 and Blackburn from 2 original Mullard UCL83 coded
mG1
B8B
and perhaps rubber stamp mark , under platter mat of "Ref No. 5809"
I've added a stretched strip of bicycle inner tube over the rim as a
soft rubber tyre, (gum glued and squashed in place) and .5mm
compensation padding washers to get the 45 and 33 rpm speeds working,
previously just the 78rpm working. Otherwise swivel-linkage metalwork
bottoms-out and would not make contact between stepped drive "cone" and
platter rim interior, without added rim or perhaps due to hard rubber
disc shrinkage .Still no 16rpm but no problem with that.
Is there a tutorial somewhere on www for the Auto mechanism as it has
the promise of working but temperamental, sometimes does the reverse of
the selected function

 

I always thought the operation of those was knda funky. The way it detects disk size for example. I don't remember if those were the ones that could actually auto select the speed as well, but that's neither here nor there.

We saw Collaros in Magnavox console stereos over here. Into the 1970s they had a trimmed down version with a lighter arm. I am pretty sure those did NOT auto select the speed, and I can't remember where I saw that, but it is rare as nen's teeth.

With these rim drive turntables you don't have to add any rubber coating to any metal. There were people in the US who would rerubber these idler tires actually. One thing about those tires - the size is not critical to speed.. Of course they must be within spec enough for the mechanism to work, but the diameters that matter are the insside of the drivien surface of the platter and the motor shaft. The only issue is making sure it engages and disengages.

Have fun with it.

 

[N_Cook]

On 21/04/2014 10:15, N_Cook wrote:

In Philco A3762, i have the schematic but mechanical problems
Would there have been a rubber tyre on the rim of the left hand drive
pulley , shown in this pic , half way down
http://www.lencoheaven.net/forum/index.php?topic=11426.0
right hand one is for PTO use.
Perhaps red rubber like the platter mat (I remember replacing a
perished/hard/split BeoGram drive tyre that was red)
The images shown above have a hint of a circular mark set inside of the
rim proper, both sides , as though something was fitted there at one
time. This one has the same marks but no sign of any tyre inside
(someone had been inside under the platter so perhaps they disposed off
remains)
Dated from to 1958 and Blackburn from 2 original Mullard UCL83 coded
mG1
B8B
and perhaps rubber stamp mark , under platter mat of "Ref No. 5809"
I've added a stretched strip of bicycle inner tube over the rim as a
soft rubber tyre, (gum glued and squashed in place) and .5mm
compensation padding washers to get the 45 and 33 rpm speeds working,
previously just the 78rpm working. Otherwise swivel-linkage metalwork
bottoms-out and would not make contact between stepped drive "cone" and
platter rim interior, without added rim or perhaps due to hard rubber
disc shrinkage .Still no 16rpm but no problem with that.
Is there a tutorial somewhere on www for the Auto mechanism as it has
the promise of working but temperamental, sometimes does the reverse of
the selected function

http://www.diverse.4mg.com/corrola1.jpg
Red "A" mark the gound surfaces that mate with the sintered metal
cylinder attached to the platter. Between them is the cast metal surface
, recessed back a few thou/mil with a countersunk hole and then a tapped
hole inside. Some sort of closure to keep oil inside but bleed out to a
missing felt pad ? I don't think the hole passes through to the core
that carries the mult-disc changer linkage, ie sealed to oil seepage to
the interior

 

[N_Cook]

On 21/04/2014 16:04, jurb6006@gmail.com wrote:

I always thought the operation of those was knda funky. The way it detects disk size for example. I don't remember if those were the ones that could actually auto select the speed as well, but that's neither here nor there.

We saw Collaros in Magnavox console stereos over here. Into the 1970s they had a trimmed down version with a lighter arm. I am pretty sure those did NOT auto select the speed, and I can't remember where I saw that, but it is rare as nen's teeth.

With these rim drive turntables you don't have to add any rubber coating to any metal. There were people in the US who would rerubber these idler tires actually. One thing about those tires - the size is not critical to speed.. Of course they must be within spec enough for the mechanism to work, but the diameters that matter are the insside of the drivien surface of the platter and the motor shaft. The only issue is making sure it engages and disengages.

Have fun with it.

I think the record size determination is the little metal "semaphore"
arm that sticks inwards from the large post. If it leaves the arm
untouched then a single, if 12 inch then it moves the arm down and that
cross-links to the tonearm-drop mechanism, 78s don't know , perhaps
manual for them, 1950s anyway not 1930s. I don't think there is a
cross-link to the speed change system.
The original rim surface of the drive disc is too rough for driving the
platter, I would have thought, perhaps originally it was as smooth as
the PTO one but breaks up in use like cassette tape pinch wheels, or
tyred of course.

 

[N_Cook]

The info here
http://www.vintage-radio.net/forum/showthread.php?t=68177

http://www.vintage-radio.net/forum/showthread.php?t=46456&highlight=collaro+conquest

is very similar model.

 

On Monday, April 21, 2014 5:15:00 AM UTC-4, N_Cook wrote:

In Philco A3762, i have the schematic but mechanical problems

Would there have been a rubber tyre on the rim of the left hand drive

pulley , shown in this pic , half way down

http://www.lencoheaven.net/forum/index.php?topic=11426.0

right hand one is for PTO use.

Perhaps red rubber like the platter mat (I remember replacing a

perished/hard/split BeoGram drive tyre that was red)

The images shown above have a hint of a circular mark set inside of the

rim proper, both sides , as though something was fitted there at one

time. This one has the same marks but no sign of any tyre inside

(someone had been inside under the platter so perhaps they disposed off

remains)

Dated from to 1958 and Blackburn from 2 original Mullard UCL83 coded

mG1

B8B

and perhaps rubber stamp mark , under platter mat of "Ref No. 5809"

I've added a stretched strip of bicycle inner tube over the rim as a

soft rubber tyre, (gum glued and squashed in place) and .5mm

compensation padding washers to get the 45 and 33 rpm speeds working,

previously just the 78rpm working. Otherwise swivel-linkage metalwork

bottoms-out and would not make contact between stepped drive "cone" and

platter rim interior, without added rim or perhaps due to hard rubber

disc shrinkage .Still no 16rpm but no problem with that.

Is there a tutorial somewhere on www for the Auto mechanism as it has

the promise of working but temperamental, sometimes does the reverse of

the selected function

I've had some luck on occasion stretching an O ring onto the rim. As Jurb has already said size doesn't matter, (although I might add at least not in this case). You might have to go to an auto parts store, a plumbing supply or a transmission rebuilder for such a ring though, and it may have to be glued in place if the rim has no shoulders. Lenny

 

[N_Cook]

On 22/04/2014 05:20, captainvideo462009@gmail.com wrote:

On Monday, April 21, 2014 5:15:00 AM UTC-4, N_Cook wrote:
In Philco A3762, i have the schematic but mechanical problems

Would there have been a rubber tyre on the rim of the left hand drive

pulley , shown in this pic , half way down

http://www.lencoheaven.net/forum/index.php?topic=11426.0

right hand one is for PTO use.

Perhaps red rubber like the platter mat (I remember replacing a

perished/hard/split BeoGram drive tyre that was red)

The images shown above have a hint of a circular mark set inside of the

rim proper, both sides , as though something was fitted there at one

time. This one has the same marks but no sign of any tyre inside

(someone had been inside under the platter so perhaps they disposed off

remains)

Dated from to 1958 and Blackburn from 2 original Mullard UCL83 coded

mG1

B8B

and perhaps rubber stamp mark , under platter mat of "Ref No. 5809"

I've added a stretched strip of bicycle inner tube over the rim as a

soft rubber tyre, (gum glued and squashed in place) and .5mm

compensation padding washers to get the 45 and 33 rpm speeds working,

previously just the 78rpm working. Otherwise swivel-linkage metalwork

bottoms-out and would not make contact between stepped drive "cone" and

platter rim interior, without added rim or perhaps due to hard rubber

disc shrinkage .Still no 16rpm but no problem with that.

Is there a tutorial somewhere on www for the Auto mechanism as it has

the promise of working but temperamental, sometimes does the reverse of

the selected function

I've had some luck on occasion stretching an O ring onto the rim. As Jurb has already said size doesn't matter, (although I might add at least not in this case). You might have to go to an auto parts store, a plumbing supply or a transmission rebuilder for such a ring though, and it may have to be glued in place if the rim has no shoulders. Lenny

The pulley here is just a 2mm thick hard rubberdisc, so the only way of
tyring it , is to pre-stretch , over night, some inner tube and then fit
it over the edge, draped over each face, holds quite well but glued for
reassurance

A B&O I dealt with sometime weighed the record to set what size it was.
This one , going by the vintage audio thread ref'd elesewhere here.
The bod wiht the jammed and broken main bearing. Just the sort of damage
I could expect from a short countersunk 6BA screw working loose and
getting jammed in that central area. So hippocratic fashion and do no
harm. Not knowing what went in there and its function. As the tapped
hole does connect through to the axis, I'll fill with hotmelt glue as a
bung and pack grease in the gap space.

 

[N_Cook]

I don't know how many times I've picked up this deck, but it must have
been always the same way round. Until this morning and on the other side
of the main stem is an exactly similar countersunk hole with a small
screw in it. Must be for fixing 2 cylindrical parts together. Other than
checking for tightness I don't think I'll fix a screw in the other side
, as there is perhaps a liklihood of them loosening over time, unless it
turns out that it gives the mechanism a malfunction with only 1 fixing

 

[N_Cook]

All that mechanical rat's nest is now working, except for 16RPM and have
not tried stacking records (I've only one single for test purposes) but
the hold and drop mechanism works for one and clamping arm, last record
height sensing, for final eject works.
Now to fit 3 core earthed cable, someone previously had connected record
deck metalwork to mains neutral, not just the isolated lowside
(theoretically if house wiring is standard) amp chasis

 

[N_Cook]

Deck run off the mains at near enough correct speed (shaded pole type)
counting revs in a minute.
Try with the amp and very sluggish. Looks as though the deck could never
have worked as is. The schematic shows 160V ,.1A motor used as a dropper
for 2x 40V valve heaters and 3.5V pilot bulb for 240V mains. Perhaps
someone changed the motor back in history to the present 240V, 14W one
and gave up.
The only way to run this is add a dropper for the heaters and rewire the
motor direct off 240V

 

[N_Cook]

Small output impedance matching transformer for 7W output, DC resistance
of primaries measuring 746 and 350 ohm , inductance 1.95uH/2.1uH, would
that amount of winding resistance disparity be expected?

 

[N_Cook]

On 08/05/2014 14:53, N_Cook wrote:

Small output impedance matching transformer for 7W output, DC resistance
of primaries measuring 746 and 350 ohm , inductance 1.95uH/2.1uH, would
that amount of winding resistance disparity be expected?

Must be normal. Distortion, partial half-wave , due to a failing
coupling cap, replaced the TCC Plastiseal rod caps that look like waxed
caps and all ok. Removed the speaker to have a look at the Calibri
Electrostatic HT64 speaker, working order to above 12KHz, just curious
,not seen one before