BG: OK let's give it a try. This time I will get it right about where the
guides are

Originally this machine had four guides:
(1) one solidly affixed to left of erase head
(2) one on left of record head, but affixed to the transport frame
(3) One spot welded to the right side of the record head
(4) One affixed (with miniature screw) to left side of PB head

The one on the right side of the record head is less than a cm from the
guide on the left of the PB head (PB head guide is effectively missing, not
repairable, mangled)

As far as stability of the tape going across the heads goes, I feel that
the 3 remaining guides will be enough, if they are aligned

The two problems are as follows:

(1) The guide to the left of the record head is affixed to frame and all
other guides must correspond to this one or the tape will not ride smoothly
on the heads.

(2) Seems like the guide to the right of the record head should not effect
the path of the tape over the PB head because it is over the screw that is
not for adjustment (the mounting screw that is tightened and not
adjustable). BUT, it does because I didn't notice the 3rd head when I was
adjusting the azimuth for the record head (I thought it was the playback
head at the time). Turning the azimuth adjustment for the record head
affects the path of the tape over the PB head. I recall seeing the PB
amplitude vary on a scope as the azimuth screw for Rec head was turned.

I hope I have written this in a readable manner.

All I can see is that I should adjust the Rec and PB heads over and over
until hopefully they are aligned.

Any ideas or warnings, BG? Thanks for your help. Your advice has given me
a much needed understanding of this situation. Mark
"bg" wrote in message
...
Just about every deck I've ever seen has a guide on the ingoing side of
the
erase head and a guide on the outgoing side of the playback head, with no
other guides in between. It is also common practise to affix the guides to
the heads, not the chassis. On the chassis there will be posts that hold
the shell in place, they are not tape guides.
I have plenty of time . If you are ready to continue let me know
bg
Marko wrote in message ...
BG: I have reread your post several times and now realize that without
the
guide on the PB head then it is up to me and luck to get it going right.

Unless you have some more advice, thanks much, you've been a great help.
Sincerely, Mark

"bg" wrote in message
...
The heads from left to right are, the erase head, the record head and
the
playback head. Any cassette I've ever seen has a guide attached to the
playback head. If possible, bend the damaged guide back into place.
Usually
this guide is spot welded, therefore the height of the guide might not
have
changed. This guide sets the tracking which usually is not adjustable
because the guide is fixed to the playback head at the factory. On rare
occasions this guide is adjustable.
The tilt of the head sets azimuth which is adjustable on all decks. You
will
have to examine the record and playback heads to see if there is
azimuth
adjustments for both heads. I would expect there is. Head height raises
or
lowers the position of the head gaps on the tape. Azimuth rotates the
gaps
so that they are aligned perpendicular (90 degrees) to the tape.
Azimuth
will have a slight effect on the head height. Another head adjustment
you
might have is zenith. Usually located at the rear of the head, it
tilts
the
face of the head, so that the head is parallel to the tape. This
adjustment
if incorrect, would tilt the top of the head either closer or further
from
the tape than the bottom of the head. It causes uneven head wear and it
causes the tape to scew up and down. As the tape scews, the azimuth and

tracking will also be out of adjustment. The erase head should also
have
a
non adjustable guide affixed to it.
Check to see that you have these guides in place, the azimuth and
zenith
adjustments, and that the adjustments will move the heads. If you can't
physically align the heads, or the guides are bad, there is no sense in
going any further. you will have to replace whatever mechanics are bad.
You might want to sacrafice an old cassette by cutting away the plastic
shell in the area where the heads contact the tape. This will give you
the
abiltiy to see how the tape rides over the heads. If the tape is
visibly
moving up or down, you will have to correct this. It is impossible to
align
a head to tape that moves all over the place. The basic concept is to
set
all guides at the same height so that the tape enters the shell and
leaves
the shell at the same height. Any guides in between should not raise or
lower the tape as it travels thru the shell.
Post back here with your results and we'll determine the next step.
bg


Marko wrote in message ...
BG: I thought I would check for replies just one more time before I
stopped
NG activity for awhile. Glad I did.


I have a signal generator, alignment tape, scope, and HP5210 freq
meter
that
I have used to set the motor RPM with 1KHz test tone.

I haven't checked yet, but I am hoping that

(1) the head on the far right is the play head
(2) the tape monitor switch will allow me to record a test tone (I
will
use
10KHz) and then monitor it with the play head so that I can align the
record
head.
(3) that the tape guide on the PB head (which has been bent out of the
tape
path) is not necessary for proper tape transfer over the heads.

What worries me is that the tape guide is on the record head and I
must
align the playback head first.

I didn't notice the third head at first and aligned the playback with
the
record head adjustment screw. This worked because the tape guide is
on
the
record head.

How do I start out with proper alignment of the two tape guides before
aligning the heads? One guide, the first one, is affixed to the
transport
frame and the second guide is affixed to the record head. I think
this
problem may have been encountered by
whoever worked on it before it was sent to a resale shop. I could see
that
they had disturbed the paint on the screws. It also had two stretched
belts
and a very dirty rec/play switch on the board, so I'm not sure. The
belts
may have stretched and the grease in the switch may have dried from
sitting
on the shelf for years after they encountered the alignment problem.

What do you suggest? Sincerely, Mark (this is a top post)






----- Original Message -----
From: "bg"
Newsgroups: sci.electronics.repair
Sent: Sunday, July 27, 2003 11:46 PM
Subject: Fisher cassette heads


You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback
heads.
I
assume that the one in the middle, the large one, is the record
head.

I have a professional alignment tape. How does one align the
record
head?
There is a tape monitor switch which probably is used to compare
input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of
the
record head) is affixed to the transport frame. The second guide
is
affixed
to the record head. The third tape guide on the playback head is
bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for
adjustment
(sloppy
design). The third tape guide is probably not necessary since it
is
only
about a cm from the guide on the record head. This transport may
be
a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark





"bg" wrote in message
...
You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback
heads.
I
assume that the one in the middle, the large one, is the record
head.

I have a professional alignment tape. How does one align the
record
head?
There is a tape monitor switch which probably is used to compare
input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of
the
record head) is affixed to the transport frame. The second guide
is
affixed
to the record head. The third tape guide on the playback head is
bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for
adjustment
(sloppy
design). The third tape guide is probably not necessary since it
is
only
about a cm from the guide on the record head. This transport may
be
a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark