Rega RB300 turntable...

[Arfa Daily]

Hi all

Anyone happen to know the value of the resistor in the CR network connected
in the synchronous motor feed ? Looks like brown - red - brown so 120 ohms,
but it's well overheated and discoloured, with a nice burn mark right around
the spiral element, right in the centre. Can't get a reading from either end
to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody
think of a reason *not* to use a wirewound rather than the original metal
film type ?

Arfa

 

[N_Cook]

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:Gx7In.61132$6C.51055@newsfe15.ams2...

Hi all

Anyone happen to know the value of the resistor in the CR network
connected
in the synchronous motor feed ? Looks like brown - red - brown so 120
ohms,
but it's well overheated and discoloured, with a nice burn mark right
around
the spiral element, right in the centre. Can't get a reading from either
end
to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody
think of a reason *not* to use a wirewound rather than the original metal
film type ?

Arfa

Wasn't Rega tonearms only?
What sort of vintage is the deck? Is it definitely for use on 240V mains ?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

 

[Adam Sampson]

"N_Cook" <diverse@tcp.co.uk> writes:

Wasn't Rega tonearms only?

No, but the RB300 is indeed a tonearm, rather than a turntable. There
are PDF manuals on vinylengine.com for a bunch of Rega tonearms and
turntables which might help identify what the deck actually is.

It's worth noting that the discussion on the page for the Planar 3
(which would be a plausible turntable to have an RB300 fitted) has some
comments on replacement motor resistor values, with one comment
suggesting 150 ohm 5%:
http://www.vinylengine.com/library/rega/planar-3.shtml

--
Adam Sampson <ats@offog.org> <http://offog.org/>

 

[Arfa Daily]

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:hsr215$lak$1@news.eternal-september.org...

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:Gx7In.61132$6C.51055@newsfe15.ams2...
Hi all

Anyone happen to know the value of the resistor in the CR network
connected
in the synchronous motor feed ? Looks like brown - red - brown so 120
ohms,
but it's well overheated and discoloured, with a nice burn mark right
around
the spiral element, right in the centre. Can't get a reading from either
end
to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody
think of a reason *not* to use a wirewound rather than the original metal
film type ?

Arfa



Wasn't Rega tonearms only?
What sort of vintage is the deck? Is it definitely for use on 240V mains ?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://diverse.4mg.com/index.htm

Well, sort of. I guess that the full deck is probably a Rega Planar 3, but
definitely a Rega-original product. There is a "Grahams HiFi London" tested
sticker on the bottom with a handwritten date of '86 on it. There is a
manufacturer's label on the bottom also saying "rega Made in Britain" and
"Rega Research Ltd"

To the best of my knowledge, it has always been used here in the UK.The
motor is a synchronous type, 4 wire, and marked 110v 50Hz. Two grey wires go
straight to mains neutral. Switched mains live comes back to a small
(original looking) PCB in the motor compartment. It passes through the R in
question to to the motor red wire. There is then a cap, 0.22u 400v
polyester, between the red wire and the blue wire, so I guess that this RC
combination is a phase shift / AC dropper so that the motor is happy at
240v. There is no indication on any of the labels as to the voltage specs,
but the fact that it is a 50Hz synchronous motor single speed deck, and also
that the mains lead is absolutely original and coloured blue and brown,
would suggest that this was built for use in europe on 50Hz mains of at
least 220v ??

Arfa

 

[Arfa Daily]

"Adam Sampson" <ats@offog.org> wrote in message
news:y2ahbm66bmr.fsf@cartman.at.offog.org...

"N_Cook" <diverse@tcp.co.uk> writes:

Wasn't Rega tonearms only?

No, but the RB300 is indeed a tonearm, rather than a turntable. There
are PDF manuals on vinylengine.com for a bunch of Rega tonearms and
turntables which might help identify what the deck actually is.

It's worth noting that the discussion on the page for the Planar 3
(which would be a plausible turntable to have an RB300 fitted) has some
comments on replacement motor resistor values, with one comment
suggesting 150 ohm 5%:
http://www.vinylengine.com/library/rega/planar-3.shtml

--
Adam Sampson <ats@offog.org> <http://offog.org/

Thanks Adam. It is indeed a Planar 3. I had in fact already been on that
site, and seen the reference to the 150 ohm resistor. I suppose it's
possible that there might be more than one value having been fitted over the
life of production, because given 40 odd years of looking at burnt and
discoloured resistor stripes, I definitely would not have said that the
middle one was originally green, but who knows ? (well, hopefully someone on
one of these groups does ! ) I was pretty sure that the first two were
brown and red for 1- 2 - something. I was just concerned that if the final
band was red, or even orange, I didn't want to be putting 120 ohms in there
....

Arfa

 

[Arfa Daily]

"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.05.17.12.09.11@gmail.com...

On Mon, 17 May 2010 09:57:09 +0100, Arfa Daily wrote:

Hi all

Anyone happen to know the value of the resistor in the CR network
connected in the synchronous motor feed ? Looks like brown - red - brown
so 120 ohms, but it's well overheated and discoloured, with a nice burn
mark right around the spiral element, right in the centre. Can't get a
reading from either end to the burn point. Looks at a guess to be rated
about 3 -5 watts. Anybody think of a reason *not* to use a wirewound
rather than the original metal film type ?

Arfa

Did you try a 120 and see what happens (with some current limiting in
place) With things like this I usually clip in a light fuse in case the
resistor was actually 1200 ohms or more

If no closer to a definitive answer by tomorrow, Meat, I'll probably go down
that route.

Arfa

 

[Meat Plow]

On Mon, 17 May 2010 09:57:09 +0100, Arfa Daily wrote:

Hi all

Anyone happen to know the value of the resistor in the CR network
connected in the synchronous motor feed ? Looks like brown - red - brown
so 120 ohms, but it's well overheated and discoloured, with a nice burn
mark right around the spiral element, right in the centre. Can't get a
reading from either end to the burn point. Looks at a guess to be rated
about 3 -5 watts. Anybody think of a reason *not* to use a wirewound
rather than the original metal film type ?

Arfa

Did you try a 120 and see what happens (with some current limiting in
place) With things like this I usually clip in a light fuse in case the
resistor was actually 1200 ohms or more

 

[DaveD]

Arfa Daily wrote:

Hi all

Anyone happen to know the value of the resistor in the CR network connected
in the synchronous motor feed ? Looks like brown - red - brown so 120 ohms,
but it's well overheated and discoloured, with a nice burn mark right around
the spiral element, right in the centre. Can't get a reading from either end
to the burn point. Looks at a guess to be rated about 3 -5 watts. Anybody
think of a reason *not* to use a wirewound rather than the original metal
film type ?

Arfa


Hi Arfa

Just took the cover off a Rega Planar 3 and the board has 5 components
on it.
1 x .22uf 275v ac cap (220nf)
1 x 10k 5% 1-2 watt parallel (physically) to the cap (bn bk or -gold)
1 x 1M 1% 1/4 watt (br bk bk yell -bn)
1 x 3k3 1% 1/4 watt (or or bk bn -bn)
1 x 120nf 400v dc cap
HTH
DaveD

 

[Arfa Daily]

"DaveD" <marday@ihug.co.nz> wrote in message
news:hsriq2$klj$1@lust.ihug.co.nz...

Arfa Daily wrote:
Hi all

Anyone happen to know the value of the resistor in the CR network
connected in the synchronous motor feed ? Looks like brown - red - brown
so 120 ohms, but it's well overheated and discoloured, with a nice burn
mark right around the spiral element, right in the centre. Can't get a
reading from either end to the burn point. Looks at a guess to be rated
about 3 -5 watts. Anybody think of a reason *not* to use a wirewound
rather than the original metal film type ?

Arfa
Hi Arfa
Just took the cover off a Rega Planar 3 and the board has 5 components on
it.
1 x .22uf 275v ac cap (220nf)
1 x 10k 5% 1-2 watt parallel (physically) to the cap (bn bk or -gold)
1 x 1M 1% 1/4 watt (br bk bk yell -bn)
1 x 3k3 1% 1/4 watt (or or bk bn -bn)
1 x 120nf 400v dc cap
HTH
DaveD

Hmmm. Well Dave, I've got to say that that bears no relationship to what's
in this one, at all :-\

It definitely says "Rega Planar 3" at the top front right corner, although
it's hard to see as the letters are just black 'shininess' within the black
satin anodised finish of the cabinet. Underneath, directly under the motor,
is a cover secured by two screws, When this is removed, the motor and a
small PCB are revealed. The PCB has just two components on it - the burnt up
R, which is a large 'film' type, I guess something like about 5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those green MKT
monobloc types. These two components are mounted 'on the slant' on the
board. The mains comes in, and the neutral is joined immediately to two grey
wires from the motor. The live leaves the board again on a white wire which
goes to the on / off switch at the front top left of the deck. Live returns
to the board on another white, and goes to the motor red lead via the burnt
up resistor. The cap is between the red lead and the remaining blue lead.
Doesn't sound much like the example that you're looking at, eh ?

Mind you, dunno about you, but I find this all the time with 'high-end'
gear. Guts that are nothing like what the the service manuals say they
should be, poorly done mods involving extra components stuck across boards,
bog-standard cheap as chips lasers fitted to CD players costing thousands,
metalwork that fits where it touches, holes drilled in wrong places,
inappropriate screw types and sizes - the list is endless.

I know that these things are often hand-built, which I guess is what
attracts the people with more money than sense to them, but when I look at
some items, I wonder how the companies that made them, and then stuck the
multi-thousand pound price tags on them, sleep at night. I guess I've just
got too much of a conscience ...

Anyways, I think tomorrow that I am going to fit a 5 watt 150 ohm wirewound
that I have to hand, and then bring it up gently on the variac, and see what
happens. I guess it's got two chances ...

Arfa

 

[Geo]

On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily" <arfa.daily@ntlworld.com>
wrote:

It definitely says "Rega Planar 3" at the top front right corner, although
it's hard to see as the letters are just black 'shininess' within the black
satin anodised finish of the cabinet. Underneath, directly under the motor,
is a cover secured by two screws, When this is removed, the motor and a
small PCB are revealed. The PCB has just two components on it - the burnt up
R, which is a large 'film' type, I guess something like about 5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those green MKT
monobloc types. These two components are mounted 'on the slant' on the
board. The mains comes in, and the neutral is joined immediately to two grey
wires from the motor. The live leaves the board again on a white wire which
goes to the on / off switch at the front top left of the deck. Live returns
to the board on another white, and goes to the motor red lead via the burnt
up resistor. The cap is between the red lead and the remaining blue lead.
Doesn't sound much like the example that you're looking at, eh ?

How about this version from mine - looks like a 15k 5% (old 2-5w carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

 

[Arfa Daily]

"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...

On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily" <arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner, although
it's hard to see as the letters are just black 'shininess' within the
black
satin anodised finish of the cabinet. Underneath, directly under the
motor,
is a cover secured by two screws, When this is removed, the motor and a
small PCB are revealed. The PCB has just two components on it - the burnt
up
R, which is a large 'film' type, I guess something like about 5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those green
MKT
monobloc types. These two components are mounted 'on the slant' on the
board. The mains comes in, and the neutral is joined immediately to two
grey
wires from the motor. The live leaves the board again on a white wire
which
goes to the on / off switch at the front top left of the deck. Live
returns
to the board on another white, and goes to the motor red lead via the
burnt
up resistor. The cap is between the red lead and the remaining blue lead.
Doesn't sound much like the example that you're looking at, eh ?

How about this version from mine - looks like a 15k 5% (old 2-5w carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same configuration. It's
actually a different motor in yours, but the supply still goes to the red
via the resistor, and the cap still appears to be between red and blue, and
the same value, although a different type. Based on that, I think I'm going
to start with 15k now, and see if the motor runs, and if it does, if it has
enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy. Appreciated.

Arfa

 

[DaveD]

Arfa Daily wrote:

"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily" <arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner, although
it's hard to see as the letters are just black 'shininess' within the
black
satin anodised finish of the cabinet. Underneath, directly under the
motor,
is a cover secured by two screws, When this is removed, the motor and a
small PCB are revealed. The PCB has just two components on it - the burnt
up
R, which is a large 'film' type, I guess something like about 5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those green
MKT
monobloc types. These two components are mounted 'on the slant' on the
board. The mains comes in, and the neutral is joined immediately to two
grey
wires from the motor. The live leaves the board again on a white wire
which
goes to the on / off switch at the front top left of the deck. Live
returns
to the board on another white, and goes to the motor red lead via the
burnt
up resistor. The cap is between the red lead and the remaining blue lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same configuration. It's
actually a different motor in yours, but the supply still goes to the red
via the resistor, and the cap still appears to be between red and blue, and
the same value, although a different type. Based on that, I think I'm going
to start with 15k now, and see if the motor runs, and if it does, if it has
enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy. Appreciated.

Arfa


Hi Arfa

Further info. The data I supplied earlier was from the Planar 3 upgrade
motor assembly.
I have just pulled out the old motor and PCB.
It has only 2 components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa.
1 x 12k 2-3 watt resistor, 8.5mm dia x 25mm long.
The resistor is a mid brown body colour and the bands are quite hard to
read but measurement confirms 12k 5% (as in brown red orange gold) The
brown and orange are hard to differentiate
The motor is a Philips 110v 50hz 250 rpm (12NC 990411131613) date of
manufacture 1985 with the same colour leads
I would suggest going with what you have in the 12 - 15k ~ 5 watt
resistor. Check that the voltage to the motor is in the region of 110v
under load and it should be good to go
Cheers
DaveD

 

[Arfa Daily]

"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...

Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner,
although
it's hard to see as the letters are just black 'shininess' within the
black
satin anodised finish of the cabinet. Underneath, directly under the
motor,
is a cover secured by two screws, When this is removed, the motor and a
small PCB are revealed. The PCB has just two components on it - the
burnt up
R, which is a large 'film' type, I guess something like about 5mm
diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those
green MKT
monobloc types. These two components are mounted 'on the slant' on the
board. The mains comes in, and the neutral is joined immediately to two
grey
wires from the motor. The live leaves the board again on a white wire
which
goes to the on / off switch at the front top left of the deck. Live
returns
to the board on another white, and goes to the motor red lead via the
burnt
up resistor. The cap is between the red lead and the remaining blue
lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same configuration.
It's actually a different motor in yours, but the supply still goes to
the red via the resistor, and the cap still appears to be between red and
blue, and the same value, although a different type. Based on that, I
think I'm going to start with 15k now, and see if the motor runs, and if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3 upgrade
motor assembly.
I have just pulled out the old motor and PCB.
It has only 2 components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa.
1 x 12k 2-3 watt resistor, 8.5mm dia x 25mm long.
The resistor is a mid brown body colour and the bands are quite hard to
read but measurement confirms 12k 5% (as in brown red orange gold) The
brown and orange are hard to differentiate
The motor is a Philips 110v 50hz 250 rpm (12NC 990411131613) date of
manufacture 1985 with the same colour leads
I would suggest going with what you have in the 12 - 15k ~ 5 watt
resistor. Check that the voltage to the motor is in the region of 110v
under load and it should be good to go
Cheers
DaveD

Many thanks Dave. That's it exactly. I just had a look, and I haven't got a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer (he's
already put up with me being away on holiday for 2 weeks !), I'm going to
put three of those in parallel as there's plenty of room. Thanks again, all.

Arfa

 

[N_Cook]

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:FfsIn.24657$Lg1.16488@newsfe17.ams2...

"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...
Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner,
although
it's hard to see as the letters are just black 'shininess' within the
black
satin anodised finish of the cabinet. Underneath, directly under the
motor,
is a cover secured by two screws, When this is removed, the motor and
a
small PCB are revealed. The PCB has just two components on it - the
burnt up
R, which is a large 'film' type, I guess something like about 5mm
diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those
green MKT
monobloc types. These two components are mounted 'on the slant' on
the
board. The mains comes in, and the neutral is joined immediately to
two
grey
wires from the motor. The live leaves the board again on a white wire
which
goes to the on / off switch at the front top left of the deck. Live
returns
to the board on another white, and goes to the motor red lead via the
burnt
up resistor. The cap is between the red lead and the remaining blue
lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same configuration.
It's actually a different motor in yours, but the supply still goes to
the red via the resistor, and the cap still appears to be between red
and
blue, and the same value, although a different type. Based on that, I
think I'm going to start with 15k now, and see if the motor runs, and
if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3 upgrade
motor assembly.
I have just pulled out the old motor and PCB.
It has only 2 components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa.
1 x 12k 2-3 watt resistor, 8.5mm dia x 25mm long.
The resistor is a mid brown body colour and the bands are quite hard to
read but measurement confirms 12k 5% (as in brown red orange gold) The
brown and orange are hard to differentiate
The motor is a Philips 110v 50hz 250 rpm (12NC 990411131613) date of
manufacture 1985 with the same colour leads
I would suggest going with what you have in the 12 - 15k ~ 5 watt
resistor. Check that the voltage to the motor is in the region of 110v
under load and it should be good to go
Cheers
DaveD

Many thanks Dave. That's it exactly. I just had a look, and I haven't got
a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer (he's
already put up with me being away on holiday for 2 weeks !), I'm going to
put three of those in parallel as there's plenty of room. Thanks again,
all.

Arfa

Is there a fuseable resistor function to the original ? ie 2 watts of
dissipation from stalled motor and the R blows rather than the motor. Would
not some 1/2 watt resistors together giving 12K be better?

 

[Arfa Daily]

"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.05.18.11.48.35@gmail.com...

On Tue, 18 May 2010 10:40:49 +0100, N_Cook wrote:

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:FfsIn.24657$Lg1.16488@newsfe17.ams2...

"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...
Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner,
although
it's hard to see as the letters are just black 'shininess' within
the black
satin anodised finish of the cabinet. Underneath, directly under
the motor,
is a cover secured by two screws, When this is removed, the motor
and
a
small PCB are revealed. The PCB has just two components on it -
the burnt up
R, which is a large 'film' type, I guess something like about 5mm
diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those
green MKT
monobloc types. These two components are mounted 'on the slant' on
the
board. The mains comes in, and the neutral is joined immediately
to
two
grey
wires from the motor. The live leaves the board again on a white
wire which
goes to the on / off switch at the front top left of the deck.
Live returns
to the board on another white, and goes to the motor red lead via
the burnt
up resistor. The cap is between the red lead and the remaining
blue lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same
configuration. It's actually a different motor in yours, but the
supply still goes to the red via the resistor, and the cap still
appears to be between red
and
blue, and the same value, although a different type. Based on that,
I think I'm going to start with 15k now, and see if the motor runs,
and
if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3
upgrade motor assembly.
I have just pulled out the old motor and PCB. It has only 2
components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa. 1 x 12k 2-3 watt
resistor, 8.5mm dia x 25mm long. The resistor is a mid brown body
colour and the bands are quite hard to read but measurement confirms
12k 5% (as in brown red orange gold) The brown and orange are hard to
differentiate The motor is a Philips 110v 50hz 250 rpm (12NC
990411131613) date of manufacture 1985 with the same colour leads I
would suggest going with what you have in the 12 - 15k ~ 5 watt
resistor. Check that the voltage to the motor is in the region of
110v under load and it should be good to go Cheers
DaveD

Many thanks Dave. That's it exactly. I just had a look, and I haven't
got
a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer (he's
already put up with me being away on holiday for 2 weeks !), I'm going
to put three of those in parallel as there's plenty of room. Thanks
again,
all.

Arfa



Is there a fuseable resistor function to the original ? ie 2 watts of
dissipation from stalled motor and the R blows rather than the motor.
Would not some 1/2 watt resistors together giving 12K be better?

He has a point.

I wouldn't have said that there was an 'implicit' fusible function to the
resistor, but I suppose that you could argue it as a secondary function. The
plate on the bottom of the deck claims that the power requirement is 4
watts, so given that the primary function of the resistor is that of a
dropper for the 110v motor, you would have to say that this equates to
around 2 watts dissipation in the motor, and the other two in the resistor.
As the original resistor is rated at around 4 watts, that would sort of
indicate that it had been dimensioned to be able to stand up to its job
without burning out. I'm not actually sure what happens to the current that
a synchronous motor draws if you stall it, but I wouldn't think that it
ramps in anything like the same way as that of a DC motor, or any kind of
brushgear AC motor ??

Arfa

 

[Meat Plow]

On Tue, 18 May 2010 10:40:49 +0100, N_Cook wrote:

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:FfsIn.24657$Lg1.16488@newsfe17.ams2...

"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...
Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right corner,
although
it's hard to see as the letters are just black 'shininess' within
the black
satin anodised finish of the cabinet. Underneath, directly under
the motor,
is a cover secured by two screws, When this is removed, the motor
and
a
small PCB are revealed. The PCB has just two components on it -
the burnt up
R, which is a large 'film' type, I guess something like about 5mm
diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of those
green MKT
monobloc types. These two components are mounted 'on the slant' on
the
board. The mains comes in, and the neutral is joined immediately
to
two
grey
wires from the motor. The live leaves the board again on a white
wire which
goes to the on / off switch at the front top left of the deck.
Live returns
to the board on another white, and goes to the motor red lead via
the burnt
up resistor. The cap is between the red lead and the remaining
blue lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same
configuration. It's actually a different motor in yours, but the
supply still goes to the red via the resistor, and the cap still
appears to be between red
and
blue, and the same value, although a different type. Based on that,
I think I'm going to start with 15k now, and see if the motor runs,
and
if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3
upgrade motor assembly.
I have just pulled out the old motor and PCB. It has only 2
components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa. 1 x 12k 2-3 watt
resistor, 8.5mm dia x 25mm long. The resistor is a mid brown body
colour and the bands are quite hard to read but measurement confirms
12k 5% (as in brown red orange gold) The brown and orange are hard to
differentiate The motor is a Philips 110v 50hz 250 rpm (12NC
990411131613) date of manufacture 1985 with the same colour leads I
would suggest going with what you have in the 12 - 15k ~ 5 watt
resistor. Check that the voltage to the motor is in the region of
110v under load and it should be good to go Cheers
DaveD

Many thanks Dave. That's it exactly. I just had a look, and I haven't
got
a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer (he's
already put up with me being away on holiday for 2 weeks !), I'm going
to put three of those in parallel as there's plenty of room. Thanks
again,
all.

Arfa



Is there a fuseable resistor function to the original ? ie 2 watts of
dissipation from stalled motor and the R blows rather than the motor.
Would not some 1/2 watt resistors together giving 12K be better?

He has a point.

 

[DaveD]

Meat Plow wrote:

On Tue, 18 May 2010 13:03:20 +0100, Arfa Daily wrote:

"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.05.18.11.48.35@gmail.com...
On Tue, 18 May 2010 10:40:49 +0100, N_Cook wrote:

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:FfsIn.24657$Lg1.16488@newsfe17.ams2...
"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...
Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right
corner, although
it's hard to see as the letters are just black 'shininess'
within the black
satin anodised finish of the cabinet. Underneath, directly under
the motor,
is a cover secured by two screws, When this is removed, the
motor and
a
small PCB are revealed. The PCB has just two components on it -
the burnt up
R, which is a large 'film' type, I guess something like about
5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of
those green MKT
monobloc types. These two components are mounted 'on the slant'
on
the
board. The mains comes in, and the neutral is joined immediately
to
two
grey
wires from the motor. The live leaves the board again on a white
wire which
goes to the on / off switch at the front top left of the deck.
Live returns
to the board on another white, and goes to the motor red lead
via the burnt
up resistor. The cap is between the red lead and the remaining
blue lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo
Yes, that's closer - although still not quite the same
configuration. It's actually a different motor in yours, but the
supply still goes to the red via the resistor, and the cap still
appears to be between red
and
blue, and the same value, although a different type. Based on
that, I think I'm going to start with 15k now, and see if the
motor runs, and
if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3
upgrade motor assembly.
I have just pulled out the old motor and PCB. It has only 2
components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa. 1 x 12k 2-3
watt resistor, 8.5mm dia x 25mm long. The resistor is a mid brown
body colour and the bands are quite hard to read but measurement
confirms 12k 5% (as in brown red orange gold) The brown and orange
are hard to differentiate The motor is a Philips 110v 50hz 250 rpm
(12NC 990411131613) date of manufacture 1985 with the same colour
leads I would suggest going with what you have in the 12 - 15k ~ 5
watt resistor. Check that the voltage to the motor is in the region
of 110v under load and it should be good to go Cheers DaveD
Many thanks Dave. That's it exactly. I just had a look, and I haven't
got
a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer
(he's already put up with me being away on holiday for 2 weeks !),
I'm going to put three of those in parallel as there's plenty of
room. Thanks again,
all.
Arfa



Is there a fuseable resistor function to the original ? ie 2 watts of
dissipation from stalled motor and the R blows rather than the motor.
Would not some 1/2 watt resistors together giving 12K be better?
He has a point.
I wouldn't have said that there was an 'implicit' fusible function to
the resistor, but I suppose that you could argue it as a secondary
function. The plate on the bottom of the deck claims that the power
requirement is 4 watts, so given that the primary function of the
resistor is that of a dropper for the 110v motor, you would have to say
that this equates to around 2 watts dissipation in the motor, and the
other two in the resistor. As the original resistor is rated at around 4
watts, that would sort of indicate that it had been dimensioned to be
able to stand up to its job without burning out. I'm not actually sure
what happens to the current that a synchronous motor draws if you stall
it, but I wouldn't think that it ramps in anything like the same way as
that of a DC motor, or any kind of brushgear AC motor ??


I thought you should cover all bases as Cook did. Not really knowing
what the pwr supply capability was I thought it at least worth looking
into. Have you an idea why the original failed?

Just another bit of info for what it is worth.
The DC resistance of the motor windings are
grey to red = 4k49
grey to blue = 4k49
red to blue = 8k99
grey to motor case greater than 20Meg
as read on my oldish dvm
The 220nf cap should be o/c also

Now I am curious as to what you find. If it is the motor, it might be
worth your customer getting the motor upgrade kit if it still available.
http://www.rega.co.uk/html/upgrade_kits.htm
Cheers
DaveD

 

[Meat Plow]

On Tue, 18 May 2010 13:03:20 +0100, Arfa Daily wrote:

"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.05.18.11.48.35@gmail.com...
On Tue, 18 May 2010 10:40:49 +0100, N_Cook wrote:

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:FfsIn.24657$Lg1.16488@newsfe17.ams2...

"DaveD" <marday@ihug.co.nz> wrote in message
news:hstcbg$lgv$1@lust.ihug.co.nz...
Arfa Daily wrote:
"Geo" <hw9j-s5hw@dea.spamcon.org> wrote in message
news:t7v2v5tt1gdnhv1k1pdmb3ntajhinru5rm@4ax.com...
On Mon, 17 May 2010 17:28:20 +0100, "Arfa Daily"
arfa.daily@ntlworld.com
wrote:


It definitely says "Rega Planar 3" at the top front right
corner, although
it's hard to see as the letters are just black 'shininess'
within the black
satin anodised finish of the cabinet. Underneath, directly under
the motor,
is a cover secured by two screws, When this is removed, the
motor and
a
small PCB are revealed. The PCB has just two components on it -
the burnt up
R, which is a large 'film' type, I guess something like about
5mm diameter
and 20mm or so long, and the 0.22u 400v cap, which is one of
those green MKT
monobloc types. These two components are mounted 'on the slant'
on
the
board. The mains comes in, and the neutral is joined immediately
to
two
grey
wires from the motor. The live leaves the board again on a white
wire which
goes to the on / off switch at the front top left of the deck.
Live returns
to the board on another white, and goes to the motor red lead
via the burnt
up resistor. The cap is between the red lead and the remaining
blue lead.
Doesn't sound much like the example that you're looking at, eh ?
How about this version from mine - looks like a 15k 5% (old 2-5w
carbon?)
http://www.8zero.co.uk/planar.jpg


--
Geo

Yes, that's closer - although still not quite the same
configuration. It's actually a different motor in yours, but the
supply still goes to the red via the resistor, and the cap still
appears to be between red
and
blue, and the same value, although a different type. Based on
that, I think I'm going to start with 15k now, and see if the
motor runs, and
if
it does, if it has enough torque to drive the platter.

Thanks very much for taking the trouble to post me the piccy.
Appreciated.

Arfa
Hi Arfa
Further info. The data I supplied earlier was from the Planar 3
upgrade motor assembly.
I have just pulled out the old motor and PCB. It has only 2
components on it.
1 x 220nf 250v ac X rated cap manufactured by Rifa. 1 x 12k 2-3
watt resistor, 8.5mm dia x 25mm long. The resistor is a mid brown
body colour and the bands are quite hard to read but measurement
confirms 12k 5% (as in brown red orange gold) The brown and orange
are hard to differentiate The motor is a Philips 110v 50hz 250 rpm
(12NC 990411131613) date of manufacture 1985 with the same colour
leads I would suggest going with what you have in the 12 - 15k ~ 5
watt resistor. Check that the voltage to the motor is in the region
of 110v under load and it should be good to go Cheers DaveD

Many thanks Dave. That's it exactly. I just had a look, and I haven't
got
a
high power 12 or 15k in stock, but I have got some 47k 2 watt film
resistors, so to save time and get the item back to the customer
(he's already put up with me being away on holiday for 2 weeks !),
I'm going to put three of those in parallel as there's plenty of
room. Thanks again,
all.

Arfa



Is there a fuseable resistor function to the original ? ie 2 watts of
dissipation from stalled motor and the R blows rather than the motor.
Would not some 1/2 watt resistors together giving 12K be better?

He has a point.

I wouldn't have said that there was an 'implicit' fusible function to
the resistor, but I suppose that you could argue it as a secondary
function. The plate on the bottom of the deck claims that the power
requirement is 4 watts, so given that the primary function of the
resistor is that of a dropper for the 110v motor, you would have to say
that this equates to around 2 watts dissipation in the motor, and the
other two in the resistor. As the original resistor is rated at around 4
watts, that would sort of indicate that it had been dimensioned to be
able to stand up to its job without burning out. I'm not actually sure
what happens to the current that a synchronous motor draws if you stall
it, but I wouldn't think that it ramps in anything like the same way as
that of a DC motor, or any kind of brushgear AC motor ??

I thought you should cover all bases as Cook did. Not really knowing
what the pwr supply capability was I thought it at least worth looking
into. Have you an idea why the original failed?

 

[Arfa Daily]

<snip>

Just another bit of info for what it is worth.
The DC resistance of the motor windings are
grey to red = 4k49
grey to blue = 4k49
red to blue = 8k99
grey to motor case greater than 20Meg
as read on my oldish dvm
The 220nf cap should be o/c also

Now I am curious as to what you find. If it is the motor, it might be
worth your customer getting the motor upgrade kit if it still available.
http://www.rega.co.uk/html/upgrade_kits.htm
Cheers
DaveD

Thanks for the link Dave. Do you know what the reasoning was behind the
'upgrade' ? Did they have a lot of trouble with motors failing ? I would say
that this is the original motor, coming up on 25 years old. I fitted the 3 x
47k combination, and the motor runs normally. It has plenty enough torque to
shift the heavy glass platter, and according to my strobe disc, the speed is
spot on. Voltage across the motor measured at 98v, which would seem right,
given that the 47k combo comes to 15.6k against the original value of 12k.
In the circumstances, I'm prepared to call 98v on a 110v nominal motor, a
draw.

I s'pose it wouldn't be a bad idea to just check the winding resistances
before it goes back, but I don't think I'll be expecting to find a problem,
as it does run correctly, without anything catching fire.

As to why the original resistor failed, anyone's guess. About 1 1/4 turns of
the spiral element have charred, right in the middle. The resistor looks as
though it has been pretty warm over its lifetime, but again, it is nearly 25
years old, so has worked hard. Could just be that it had started to go high
and suffered a cumulative cascade failure. Might have been a voltage thing.
Some of these resistors, particularly considering its age, are not rated
especially well, working voltage-wise. I suppose that over it's lifetime,
it's had around 130v RMS across it all the time that the motor was running.
Could have been a slight manufacturing defect such as the spiral being
'nicked', that has degraded down the years, to the point where it became a
failure. Endless possibilities ...

Arfa

 

[Meat Plow]

On Tue, 18 May 2010 16:50:28 +0100, Arfa Daily wrote:

snip



Just another bit of info for what it is worth. The DC resistance of the
motor windings are grey to red = 4k49
grey to blue = 4k49
red to blue = 8k99
grey to motor case greater than 20Meg as read on my oldish dvm
The 220nf cap should be o/c also

Now I am curious as to what you find. If it is the motor, it might be
worth your customer getting the motor upgrade kit if it still
available. http://www.rega.co.uk/html/upgrade_kits.htm Cheers
DaveD


Thanks for the link Dave. Do you know what the reasoning was behind the
'upgrade' ? Did they have a lot of trouble with motors failing ? I would
say that this is the original motor, coming up on 25 years old. I fitted
the 3 x 47k combination, and the motor runs normally. It has plenty
enough torque to shift the heavy glass platter, and according to my
strobe disc, the speed is spot on. Voltage across the motor measured at
98v, which would seem right, given that the 47k combo comes to 15.6k
against the original value of 12k. In the circumstances, I'm prepared to
call 98v on a 110v nominal motor, a draw.

I s'pose it wouldn't be a bad idea to just check the winding resistances
before it goes back, but I don't think I'll be expecting to find a
problem, as it does run correctly, without anything catching fire.

As to why the original resistor failed, anyone's guess. About 1 1/4
turns of the spiral element have charred, right in the middle. The
resistor looks as though it has been pretty warm over its lifetime, but
again, it is nearly 25 years old, so has worked hard. Could just be that
it had started to go high and suffered a cumulative cascade failure.
Might have been a voltage thing. Some of these resistors, particularly
considering its age, are not rated especially well, working
voltage-wise. I suppose that over it's lifetime, it's had around 130v
RMS across it all the time that the motor was running. Could have been a
slight manufacturing defect such as the spiral being 'nicked', that has
degraded down the years, to the point where it became a failure. Endless
possibilities ...

I hate endless possibilities.