Cassette Speed Adjustment Test Tape

[mcp6453]

I need a cassette alignment tape, actually for speed adjustment. Anybody
know where I can find one? I don't have a deck that I trust enough to
make my own.

 

[NSM]

I need a cassette alignment tape, actually for speed adjustment. Anybody
know where I can find one? I don't have a deck that I trust enough to
make my own.

Use a good quality pre recorded tape?

N

 

[Ken Weitzel]

Use a good quality pre recorded tape?

N

Hi...

Must be that I'm missing something here... how is an
alignment tape used to check speed?

Think I'd prefer a tape recorded on a known good (speed)
machine with a nice say 5k tone on it; then look at it on
the suspect machine with a freq counter?

Or the quick and easy way... take a commercial tape, with
song lengths printed on the label... choose the longest
song on it... play it; timing it with a stop watch and
see how close it comes

Take care.

Ken


Ken

 

[Ray L. Volts]

Hi...

Must be that I'm missing something here... how is an
alignment tape used to check speed?

I'm sure he must have been referring to a head azimuth alignment tape --
which would have at least one steady tone on it. ASTI Magnetics offers (or
at least used to offer) the more costly, single-purpose variety. Or he
could get one of the popular all-in-one tapes for $20:
http://www.electronix.com/catalog/default.php/cPath/14_222

 

[N Cook]

I need a cassette alignment tape, actually for speed adjustment. Anybody
know where I can find one? I don't have a deck that I trust enough to
make my own.

Checking the play speed of a cassette recorder.
Requirements: a 1KHz test tape or a recording of an accurate
1KHz tone made on a known good tape unit and played back on that machine
to check, and an audio signal generator
with a fully floating output ie no dc reference if not then de-couple the
output
with a couple of capacitors.Parallel together one channel of the phones
output of the tape and the output of the sig.gen. and a set of headphones
in mono (L and R connected).With approximately equal sound levels
you should get unmistakeable beat note .Reduce the beat to a minimum by
changing the speed regulation of the cassette unit motor.

Diverse Devices, Southampton, England
other electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[mcp6453]

I'm sure he must have been referring to a head azimuth alignment tape --
which would have at least one steady tone on it. ASTI Magnetics offers (or
at least used to offer) the more costly, single-purpose variety. Or he
could get one of the popular all-in-one tapes for $20:
http://www.electronix.com/catalog/default.php/cPath/14_222

No, not necessarily. There are tapes made specifically for determining
the speed of a cassette machine. They are typically 3.150 kHz. Play the
tape, measure the frequency of the tone with a frequency counter, and
adjust the speed accordingly. A commercial version is available at
http://www.jrfmagnetics.com/basftapes.html, but quite a few other
companies used to make them. I just cannot find one of those companies,
although the source suggested above may be a good one. The descriptions
on the tape do not tell what other tones are available, but I assume
that the speed test would be one of them. Thank for the pointer.

 

[mcp6453]

Checking the play speed of a cassette recorder.
Requirements: a 1KHz test tape or a recording of an accurate
1KHz tone made on a known good tape unit and played back on that machine
to check, and an audio signal generator
with a fully floating output ie no dc reference if not then de-couple the
output
with a couple of capacitors.Parallel together one channel of the phones
output of the tape and the output of the sig.gen. and a set of headphones
in mono (L and R connected).With approximately equal sound levels
you should get unmistakeable beat note .Reduce the beat to a minimum by
changing the speed regulation of the cassette unit motor.

Diverse Devices, Southampton, England
other electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

This is certainly a viable technique, but it is not as accurate as a
test tape with a frequency counter. Thanks for reminding me!

 

[JR North]

Easy to make. Produce a tone with an analog signal generator. Say 8K HZ
about 1-4 mA. Pipe it into a known good deck. Play the tape in the unit
to be adjusted into a scope. The difference in HZ is the spindle error.
JR

 

[NSM]

Must be that I'm missing something here... how is an
alignment tape used to check speed?

Think I'd prefer a tape recorded on a known good (speed)
machine with a nice say 5k tone on it; then look at it on
the suspect machine with a freq counter?

Or the quick and easy way... take a commercial tape, with
song lengths printed on the label... choose the longest
song on it... play it; timing it with a stop watch and
see how close it comes

Or get a friendly musician to listen to it and tell you if the pitches are
high or low.

N

 

[Andy Cuffe]

Easy to make. Produce a tone with an analog signal generator. Say 8K HZ
about 1-4 mA. Pipe it into a known good deck. Play the tape in the unit
to be adjusted into a scope. The difference in HZ is the spindle error.
JR

This method works very well IF you can find a known good tape deck.
When I used to work on a lot of tape decks, I don't think I ever saw
two that were even close to the same speed (usually they were too
fast). Many were off enough so that it was obvious when listening to
music. Even the two sides of double decks were rarely both the same
speed. Expensive decks also varied a lot.
Andy Cuffe

[email protected] <-- Use this address until 12/31/2005

[email protected] <-- Use this address after 12/31/2005

 

[NSM]

This method works very well IF you can find a known good tape deck.
When I used to work on a lot of tape decks, I don't think I ever saw
two that were even close to the same speed (usually they were too
fast). Many were off enough so that it was obvious when listening to
music. Even the two sides of double decks were rarely both the same
speed. Expensive decks also varied a lot.

Somewhere I have / had a cleaning tape with a built in strobe disc. Try
dollar stores?

N

 

[John T]

Hi Ken,

Or the quick and easy way... take a commercial tape, with
song lengths printed on the label... choose the longest
song on it... play it; timing it with a stop watch and
see how close it comes

Problem is the running times printed on those labels are often highly
inaccurate


John

 

[N Cook]

This is certainly a viable technique, but it is not as accurate as a
test tape with a frequency counter. Thanks for reminding me!

f counter is a bit OTT, I've never come across a cassette tape player that
is consistently within 1 c/s of beats at 1 KHz of test tape.
Perhaps something with huge motors and flywheels but not ordinary domestic
kit.

Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/