Portable record player amplifier question

[j***@yahoo.com]

I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

[Steven Dinius_]

I found one like this last week at the auction house. Chances are it's solid
state and much like a GE Wildcat. It had 4 speeds (16, 33, 45 and 78) and
was a changer much like a BSR/MacDonald or remotely like a Garrard (a
Garrard is light years away from these tables). Did you get a chance to play
it or was the needle "worn out" (real or manager-wise)?

Post by j***@yahoo.com
I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

[Gary Tayman]

I'm not familiar with this particular model, but I'd expect the amp to be a
simple one. Seems to me that some phonos of the late 50's had only one tube
in them. With this one I'd expect to see as many as four tubes, only
because it's stereo. Possibly less, with a dual triode and two outputs.
Rectifier probably is one of those smelly things. Caps are probably molded.

Personally I wouldn't think it would be that much trouble to fix, even
without a schematic. But then, have you even checked it out? Probably you
could replace that selenium thing, maybe add a dropping resistor, and be
done with it. If one side of the amp is bad, you have another one right
next to it that you can use to compare voltages.
--
Gary E. Tayman/Tayman Electrical
Sound Solutions For Classic Cars
http://www.taymanelectrical.com

Post by j***@yahoo.com
I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

[Bill Sheppard]

'El Cheapo' tube stereos of this sort often used a high output crystal
cartridge driving a pair of 50EH5s (occasionally 50C5s) directly, with
B+ supplied by one of those smelly things.
Bill(oc)

[nesesu]

Well, the last of the tube ones had 1 tube [50EH5] for each channel.
There was either a 50V tap on the phono motor winding for mono sets or
20V dropping resistor in series with both tubes in a stereo. The 50EH5
is a higher sensitivity 50C5 and can be driven directly with a ceramic
phono cart. Silicon diode for B+.

Neil S.

[Phil B]

Could be tube or SS. Find a screwdriver take a look.

Phil B.

Post by j***@yahoo.com
I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

[M]

I believe the SS version possibly says solid state in the upper right
corner. That would kill it, I'm almost certain.

Post by Phil B
Could be tube or SS. Find a screwdriver take a look.
Phil B.

Post by j***@yahoo.com
I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

[William Sommerwerck]

Post by j***@yahoo.com
I found an old Westinghouse record player at the local thrift store.
It's a turntable with speakers attached with hinges to either side -
about the size of a small piece of luggage. Does anyone know what kind
of amplifier circuits these type units have in them - assuming it's a
tube unit? The is a grill in the back, but without a flashlight I
couldn't see what was inside. I"ve never seen a schematic for a unit
like this.

"What kind of amplifier circuits?"

If it's tube -- and you can tell because it doesn't come on immediately --
it will be single-ended amplfication with an output transformer and direct
connection to the line -- no power transformer. Probably two tube sections
per channel -- one to kick up the signal from the ceramic pickup, the other
the output tube.

[Bill Sheppard]

Probably two tube sections per channel
-- one to kick up the signal from the
ceramic pickup, the other the output
tube.

The really low end stuff used only one tube per channel (typically a
50EH5). With 3V of signal driving it, there was oodles of volume but
pretty lousy fidelity, obviously.
The cheapo ceramic cartridge was a trade-off of fidelity for high
output.
oc

[j***@yahoo.com]

Thanks for the answers. I'll go the the store tomorrow with a
flashlight to see if there are any tubes in it. If it's a 50EH5 I
wouldn''t have any interest in it. It didn't say SS anywhere.

[Jeff, WB8NHV]

Some older tube-type phonographs used a one-tube amplifier, the one
tube being a 117Z3--the tube was designed to operate directly from the
AC line. The tube filament was wired in series with the phono motor,
which was usually a 90-volt (more or less) component. One major
drawback of these phonos was if the 117Z3 filament burned open, the
turntable motor would stop as well--a dead giveaway that the tube was
bad and needed replacing. (I'm not sure what happened with this system
if the tube filament shorted to the cathode; probably blew the line
fuse, as the tube was operated directly from the power line.) I don't
know the vintage of this system, but it seems to me it was used
possibly in inexpensive portable phonographs of the late 1940s. I can't
shed any light on the vintage of the unit you're describing, though. If
it uses 50-volt tubes in series in the amplifier, I'd place it
somewhere in the 1950s as a wild guess. A selenium rectifier in the
power supply would put it, again I'm guessing, in the late '50s or
early 1960s (I have a Zenith radio made in 1963 which has a selenium
stack rather than a tube rectifier).

Jeff, WB8NHV (mailto: ***@ameritech.net)
Fairport, Ohio USA

[Brenda Ann]

Post by Jeff, WB8NHV
Some older tube-type phonographs used a one-tube amplifier, the one
tube being a 117Z3--the tube was designed to operate directly from the
AC line.

Perhaps your memory is faulty.. I know mine gets that way from time to time.

A 117Z3 is a rectifier, so wouldn't do much as an amplifier..

I have seen phono setups as described using a 35L6 or 35C5.. using the phono
motor as the filament dropping device (a 70-75 volt two-pole synchronous
motor). The phono cartridge was a very high output crystal cartridge that
could directly feed the control grid of the power amp tube..

[Bill]

Post by Brenda Ann

Post by Jeff, WB8NHV
Some older tube-type phonographs used a one-tube amplifier, the one
tube being a 117Z3--the tube was designed to operate directly from the
AC line.

Perhaps your memory is faulty.. I know mine gets that way from time to time.
A 117Z3 is a rectifier, so wouldn't do much as an amplifier..

I suspect the tube being mentioned might be the 117L7/M7/N7 which is a
crazy thing with rectifier and audio amp in the same envelope. This is
the type of application they were made for.

-Bill

[Brenda Ann]

Post by Bill

Post by Brenda Ann

Post by Jeff, WB8NHV
Some older tube-type phonographs used a one-tube amplifier, the one
tube being a 117Z3--the tube was designed to operate directly from the
AC line.

Perhaps your memory is faulty.. I know mine gets that way from time to time.
A 117Z3 is a rectifier, so wouldn't do much as an amplifier..

I suspect the tube being mentioned might be the 117L7/M7/N7 which is a
crazy thing with rectifier and audio amp in the same envelope. This is
the type of application they were made for.
-Bill

Most likely, but those didn't use the motor for filament dropping. The ones
as I mentioned normally used small selenium rectifiers, and probably came
out shortly after the ones you refer to.

[Bill]

Post by Brenda Ann
Most likely, but those didn't use the motor for filament dropping.

Good point.

-Bill

[Jim Mueller]

Post by Bill

Post by Brenda Ann
Most likely, but those didn't use the motor for filament dropping.

Good point.
-Bill

As usual, there were variations. I have a GE mono portable from the 60s
that has 2 tubes, a 35W4 and a 35EH5. The tube heaters are in parallel
with each other and the pair is in series with an 85V motor.

BTW, the motors used in these things are induction motors. Synchronous
motors were too expensive. At light loads induction motors run at a
fairly constant speed, at least they're constant enough for a mass-market
record player.

[Bill Sheppard]

Post by Jeff, WB8NHV
Some older tube-type phonographs used
a one-tube amplifier, the one tube being
a 117Z3--the tube was designed to
operate directly from the AC line. The
tube filament was wired in series with
the phono motor, which was usually a
90-volt (more or less) component.

The OP stated that the unit has speakers (plural) that swing out. That
would pretty well mark it as stereo. If it's tube type, it'd have to use
at least two power tubes.
I've never seen one with the heaters in series with the
motor, although there might've been such. Usually the motor was tapped
as an autotransformer to give the required heater voltage.
Bill(oc)

[norml]

117Z3 is a half-wave rectifier--mostly used in 3-way portables.

One tube phonos usually used something like a 25L6 with the heater in
series with the motor field and a selenium rectifier.

Norm Lehfeldt

Post by Bill Sheppard

Post by Jeff, WB8NHV
Some older tube-type phonographs used
a one-tube amplifier, the one tube being
a 117Z3--the tube was designed to
operate directly from the AC line. The
tube filament was wired in series with
the phono motor, which was usually a
90-volt (more or less) component.

The OP stated that the unit has speakers (plural) that swing out. That
would pretty well mark it as stereo. If it's tube type, it'd have to use
at least two power tubes.
I've never seen one with the heaters in series with the
motor, although there might've been such. Usually the motor was tapped
as an autotransformer to give the required heater voltage.
Bill(oc)