Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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JonathanM
 
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Default Sony TC-105 Reel-to-Reel Recorder

Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards

  #2   Report Post  
Michael Black
 
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JonathanM () writes:
Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards


Is it supposed to play 4 tracks at a time? I thought 4-track often
meant stereo, in two directions, not 4 tracks at a time. Even
when 4-channel came along in the seventies, they either used a
different scheme or they used encoding (depending on the 4 channel
method).

Michael

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Paul Brooks
 
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"Michael Black" wrote in message
...

JonathanM () writes:
Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards


Is it supposed to play 4 tracks at a time? I thought 4-track often
meant stereo, in two directions, not 4 tracks at a time. Even
when 4-channel came along in the seventies, they either used a
different scheme or they used encoding (depending on the 4 channel
method).

Michael

Yes, 4 track means 2 channel stereo one direction and 2 channel stereo the
other way.
Anyway, the odds are oxidation on the record/playback switch in these old
tape recorders. Switch needs cleaning. Due to being left probably unused for
nearly half a century it's managed to get the contacts oxidised on the
rec/play switch - and if you don't know where to find that and how to clean
it take it in for repair as you are dealing with a bit of history here.

Paul


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Alan R. Betz
 
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"Michael Black" wrote in message
...


Is it supposed to play 4 tracks at a time? I thought 4-track often
meant stereo, in two directions, not 4 tracks at a time. Even
when 4-channel came along in the seventies, they either used a
different scheme or they used encoding (depending on the 4 channel
method).

Michael

Yes, 4 track means 2 channel stereo one direction and 2 channel stereo
the other way.
snip

Paul




The Sony TC-105 is a quarter track mono unit. In normal use the track
selector switch (marked "TRACK EXCH") would first be set to tracks 1,4.
After two passes of the tape, one in each direction, the switch is reset
to tracks 3,2 and two more passes are made. In this way the tracks are
recorded or played in the sequence 1, 4, 3, 2.
Alan.
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Tim Schwartz
 
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Jonathan,

I used to own a TC-105, and it is a mono machine. The switch on the
front will allow you to listen to the left or right channel, assuming a
stereo, 1/4 track tape. So the good news is that there is nothing wrong
with your tape recorder, but the bad news is it will not do what you
want it to do.

Regards,
Tim Schwartz
Bristol Electronics


JonathanM wrote:

Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards



  #6   Report Post  
JonathanM
 
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Thanks, Tim. I am pretty sure that this machine should allow me to
listen to all four tracks. After all, they were taped originally on a
similar machine in the 1970s. I have no doubt of that at all. Might
there still be another reason?


On Thu, 03 Feb 2005 13:25:46 GMT, Tim Schwartz
wrote:

Jonathan,

I used to own a TC-105, and it is a mono machine. The switch on the
front will allow you to listen to the left or right channel, assuming a
stereo, 1/4 track tape. So the good news is that there is nothing wrong
with your tape recorder, but the bad news is it will not do what you
want it to do.

Regards,
Tim Schwartz
Bristol Electronics


JonathanM wrote:

Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards


  #7   Report Post  
JonathanM
 
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Default

Thanks, Paul, I don't suppose, given your UK location, that you'd know
where in the USA I might be able to have it repaired or serviced
responsibly, would you?


On Thu, 3 Feb 2005 06:20:39 +0000 (UTC), "Paul Brooks"
wrote:


Yes, 4 track means 2 channel stereo one direction and 2 channel stereo the
other way.
Anyway, the odds are oxidation on the record/playback switch in these old
tape recorders. Switch needs cleaning. Due to being left probably unused for
nearly half a century it's managed to get the contacts oxidised on the
rec/play switch - and if you don't know where to find that and how to clean
it take it in for repair as you are dealing with a bit of history here.

Paul


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NSM
 
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JonathanM wrote in message
...
Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.


Where does it say "4 Track"? What is the age?
--
N

















  #9   Report Post  
Harvey
 
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Default


JonathanM wrote in message
...
Thanks, Tim. I am pretty sure that this machine should allow me to
listen to all four tracks. After all, they were taped originally on a
similar machine in the 1970s. I have no doubt of that at all. Might
there still be another reason?

Looking at this picture of one here
http://www.oaktreeent.com/web_photos...corder_web.jpg ,
it looks like a standard *stereo* four track tape machine. That is, it plays
two tracks on one side of the tape, and two on the other.

The tape you have was recorded on a 4-track multitrack recorder, which would
look something like one of these - http://www.electrofix.com/teac3440.HTM
and allows all four tracks to be recorded/played at the same time.




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NSM
 
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"Harvey" wrote in message
...

Looking at this picture of one here

http://www.oaktreeent.com/web_photos...corder_web.jpg ,
it looks like a standard *stereo* four track tape machine. That is, it

plays
two tracks on one side of the tape, and two on the other.


I sure don't remember any reel to reel recorder that let you flip the tape
over (or run it backwards) for extra storage. Were there any more like this?
--
N




















  #11   Report Post  
Bill Renfro
 
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I sure don't remember any reel to reel recorder that let you flip the tape
over (or run it backwards) for extra storage. Were there any more like

this?
--
N


Almost all of them did. The only ones that didn'e were pro level
multitracks. If you play a tape recorded on a multitrack on a standard 1/4
track machine you only will hear 2 of the tracks, and if you trun the tape
over you will hear the other 2 tracks but backwards. The tc-105 is a 1/4
track machine not a multitrack. It will play only 2 of the 4 tracks at any
one time.


  #12   Report Post  
Buck Frobisher
 
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"Bill Renfro" wrote in message
...
over you will hear the other 2 tracks but backwards. The tc-105 is a 1/4
track machine not a multitrack. It will play only 2 of the 4 tracks at
any
one time.


Close: it's 4 track mono. You can play only ONE of the 4 tracks at a time.
The "exchange" switch lets you choose which one on a given side.


  #13   Report Post  
NSM
 
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"Buck Frobisher" wrote in message
...
"Bill Renfro" wrote in message
...
over you will hear the other 2 tracks but backwards. The tc-105 is a

1/4
track machine not a multitrack. It will play only 2 of the 4 tracks at
any
one time.


Close: it's 4 track mono. You can play only ONE of the 4 tracks at a

time.
The "exchange" switch lets you choose which one on a given side.


Interesting. I fixed a lot of Sony's and others but never anything like
that.
--
N

















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WEBPA
 
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Don't think you never will get 4 simultaneous audio channels from a Sony TC-105
or '105A. They are 4-track, 2 channel machines. In 1/4 inch tape parlance this
means: 4 linear tracks (with guard bands) consisting of a stereo pair for each
direction.

A hint about the machine's number of tracks is: How many VU meters are on the
front panel? Two or Four. That's how many tracks it can record and play at the
same time.

Greetings --

This is a unit I have bought on eBay recently. It functions reasonably
well almost in every sense but one: I can hear only two of four
tracks. Would anyone know a reason for this? If repair is necessary,
where? I live in the Washington, DC area.

Thanks and regards





webpa

  #15   Report Post  
Buck Frobisher
 
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"WEBPA" wrote in message
...
Don't think you never will get 4 simultaneous audio channels from a Sony
TC-105
or '105A. They are 4-track, 2 channel machines. In 1/4 inch tape parlance
this
means: 4 linear tracks (with guard bands) consisting of a stereo pair for
each
direction.

A hint about the machine's number of tracks is: How many VU meters are on
the
front panel? Two or Four. That's how many tracks it can record and play
at the
same time.


Dude, it's a MONO machine. ONE VU meter. On each side of the tape the
"track exchange" switch allows you to select which of the available tracks
on that side you can play. Then you flip the tape over and have the same
choice on the other side.

In other words, -no- stereo playback. Or record, for that matter.

--
"Stay strong. Be brave. Wait for the signs."

Regards,

Frank Johansen
Aurora, Ontario




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Asimov
 
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"Buck Frobisher" bravely wrote to "All" (05 Feb 05 10:33:43)
--- on the heady topic of " Sony TC-105 Reel-to-Reel Recorder"

BF From: "Buck Frobisher"
BF Xref: aeinews sci.electronics.repair:9526

BF "WEBPA" wrote in message
BF ...
Don't think you never will get 4 simultaneous audio channels from a Sony
TC-105
or '105A. They are 4-track, 2 channel machines. In 1/4 inch tape parlance
this
means: 4 linear tracks (with guard bands) consisting of a stereo pair for
each
direction.

A hint about the machine's number of tracks is: How many VU meters are on
the
front panel? Two or Four. That's how many tracks it can record and play
at the
same time.


BF Dude, it's a MONO machine. ONE VU meter. On each side of the tape
BF the "track exchange" switch allows you to select which of the
BF available tracks on that side you can play. Then you flip the tape
BF over and have the same choice on the other side.

BF In other words, -no- stereo playback. Or record, for that matter.

BF --
BF "Stay strong. Be brave. Wait for the signs."

BF Regards,

Frank,

I have a small MONO portable German made machine with track switching
similar to that. It is a SABA TK125. When it was given the person said
it was used by a missionary in Africa, whatever... Anyways, there is
only one output tube and only one speaker but it plays back 2 tracks
at a time in MONO. There is a switch to select between 1-2 or 3-4.

The only odd thing is the DIN speaker socket has both speaker I and II
labeled. BUT it is MONO, no doubt about it. After cleaning all the
axles and relay contacts it works nicely now. It is very
pre-transistor 50's looking, in modern green plastic not bakelite.

A*s*i*m*o*v

.... That was a fascinating period of time for electronics

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NSM
 
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"Asimov" wrote in message
...

Frank,

I have a small MONO portable German made machine with track switching
similar to that. It is a SABA TK125. When it was given the person said
it was used by a missionary in Africa, whatever... Anyways, there is
only one output tube and only one speaker but it plays back 2 tracks
at a time in MONO. There is a switch to select between 1-2 or 3-4.

The only odd thing is the DIN speaker socket has both speaker I and II
labeled. BUT it is MONO, no doubt about it. After cleaning all the
axles and relay contacts it works nicely now. It is very
pre-transistor 50's looking, in modern green plastic not bakelite.


I assume that 2 or 4 track heads became available and the Japanese, as is
their wont, came up with odd designs to take advantage of them.
--
N

















  #18   Report Post  
 
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Asimov wrote:
I have a small MONO portable German made machine with track switching
similar to that. It is a SABA TK125. When it was given the person

said
it was used by a missionary in Africa, whatever... Anyways, there is
only one output tube and only one speaker but it plays back 2 tracks
at a time in MONO. There is a switch to select between 1-2 or 3-4.

The only odd thing is the DIN speaker socket has both speaker I and

II
labeled. BUT it is MONO, no doubt about it. After cleaning all the
axles and relay contacts it works nicely now. It is very
pre-transistor 50's looking, in modern green plastic not bakelite.

A*s*i*m*o*v

... That was a fascinating period of time for electronics



Most 4 track mono reel to reels have a selector switch labelled 1-4,
3-2 and PAR (parallel). Position 1-4 (or 3-2), does *not* mean you hear
both track 1 and 4 (or 3 and 2) together. It means that track 1 and 3
are the two tracks you use on side one, and after turning the reels
over you still have 4 and 2 to use on the other direction. (On a stereo
model, 1 would be left and 3 right. same for 4 and 2 on the second
side).

Labelling of the positions can be different depending on manufacturer
(grundig for example, often used the terms 1-2 and 3-4, but in reality
they meant tracks 1-4 and 3-2, same quarter track system but i think
they just simplified the names a bit for the end-user)

Quarter track r2r is not like cassette, there is a grerater space width
between the heads:
_______________
Track 4
Track 3 --Head
Track 2
Track 1 --Head
_______________

Unlike the stereo decks, It is not generally possible to record on both
1 and 3 at once on a mono deck as there is only one set of recording
circuitry, which was coupled to either the upper or lower head
depending on track selector position.

However, On playback, if the switch is set to PAR, it will feed the
upper and lower head signals to the head amp, and hence play both
tracks 1 and 3 (or tracks 2 and 4 if we're talking about side 2 of the
tape). It is thus possible to hear left and right (together!) of a
stereo tape on a mono quarter track deck.

Many mono decks had more than one speaker output, depending on how
beefy their amps were. I have some mono tandbergs like that. Some also
had a "free head output" which was an unamplfied signal from whatever
head was not being fed through the deck's internal amp at the time,
theoretically enabling you to connect an auxiliary second head amp (and
power amp, speakers etc) and get stereo.

hope some of that made sense ;-)
Ben

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