Hello all,
I'm trying to realign this VHS vcr head without any special
equipment. It has three adjustment screws,each on springs.
One in the front, to control the front height, and two at
the back (like a triangular arrangement) to control the
back height / azimuth angle.

I don't think it's critical, not using the mono
sound track.
A problem I'm observing is the 2 to 3 inches of tape
between this head, and the rightmost roller guide.

As the tape is playing, there is not even tension on the tape,
visible here as an occasional "flap" of the tape on the top edge.
The bottom edge of the tape is tight but the top is
comparatively loose.

Not sure if this due to this heads alignment, or possibly
a worn switch roller.

Any tips appreciated.
Dave

davexnet:
The A/C head "tilt" adjustment can straighten out the problem you
described with the apparent slack at the top of the tape; just don't
over do it; make certain that the tape is smooth at both the top and
bottom just before it goes past the A/C head.
And yes, the "pinch roller" (switch roller?) can have a lot to do with
smooth tape handling and proper running past the A/C head, replace it
if the A/C head tilt adjustment is not providing proper results.
electricitym
=


davexnet02 wrote:
Hello all,
I'm trying to realign this VHS vcr head without any special
equipment. It has three adjustment screws,each on springs.
One in the front, to control the front height, and two at
the back (like a triangular arrangement) to control the
back height / azimuth angle.

I don't think it's critical, not using the mono
sound track.
A problem I'm observing is the 2 to 3 inches of tape
between this head, and the rightmost roller guide.

As the tape is playing, there is not even tension on the tape,
visible here as an occasional "flap" of the tape on the top edge.
The bottom edge of the tape is tight but the top is
comparatively loose.

Not sure if this due to this heads alignment, or possibly
a worn switch roller.

Any tips appreciated.
Dave

"davexnet02" bravely wrote to "All" (02 Jan 05 01:57:24)
--- on the heady topic of "how to adjust the staionary control track/mono audio =
head ?"

da From: davexnet02
da Xref: aeinews sci.electronics.repair:5552

da Hello all,
da I'm trying to realign this VHS vcr head without any special
da equipment. It has three adjustment screws,each on springs.
da One in the front, to control the front height, and two at
da the back (like a triangular arrangement) to control the
da back height / azimuth angle.

da I don't think it's critical, not using the mono
da sound track.
da A problem I'm observing is the 2 to 3 inches of tape
da between this head, and the rightmost roller guide.

da As the tape is playing, there is not even tension on the tape,
da visible here as an occasional "flap" of the tape on the top edge.
da The bottom edge of the tape is tight but the top is
da comparatively loose.

da Not sure if this due to this heads alignment, or possibly
da a worn switch roller.

da Any tips appreciated.


Dave, it's never supposed to ride over the edge, only beside it. The
AC head isn't supposed to change top or bottom tension but if the tape
path is wrong then it might. I would suspect wear or an improperly
sitting load arm. Don't mess with the AC unless you are sure the path
is good. I bet you will find it to be okay then.

A*s*i*m*o*v

.... This message transmitted on 100% recycled photons.

On 1 Jan 2005 19:43:02 -0800, wrote:

davexnet:
The A/C head "tilt" adjustment can straighten out the problem you
described with the apparent slack at the top of the tape; just don't
over do it; make certain that the tape is smooth at both the top and
bottom just before it goes past the A/C head.
And yes, the "pinch roller" (switch roller?) can have a lot to do with
smooth tape handling and proper running past the A/C head, replace it
if the A/C head tilt adjustment is not providing proper results.
electricitym
Thank you for your comments.
The pinch roller is bad, unfortunately.
If there's a replacement available for $20,
it's worth doing. Otherwise time for a new vcr.
I'm not sure what the history of sony is regarding
the vcr quality, but this 1995 unit is cheaply made;
it will not eject with out holding open the flap.
Seems to be a bad design..

If you know of a possible source for the pinch roller,
please advise.
Thanks,
Dave

writes:

davexnet:
The A/C head "tilt" adjustment can straighten out the problem you
described with the apparent slack at the top of the tape; just don't
over do it; make certain that the tape is smooth at both the top and
bottom just before it goes past the A/C head.
And yes, the "pinch roller" (switch roller?) can have a lot to do with
smooth tape handling and proper running past the A/C head, replace it
if the A/C head tilt adjustment is not providing proper results.
electricitym

If no one messed with the A/C adjustments, they haven't changed on their
own! First try cleaning the pinch roller very thoroughly. If that seems
to help, replace it.

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Important: Anything sent to the email address in the message header above is
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davexnet02 wrote:
Hello all,
I'm trying to realign this VHS vcr head without any special
equipment. It has three adjustment screws,each on springs.
One in the front, to control the front height, and two at
the back (like a triangular arrangement) to control the
back height / azimuth angle.

I don't think it's critical, not using the mono
sound track.
A problem I'm observing is the 2 to 3 inches of tape
between this head, and the rightmost roller guide.

As the tape is playing, there is not even tension on the tape,
visible here as an occasional "flap" of the tape on the top edge.
The bottom edge of the tape is tight but the top is
comparatively loose.

Not sure if this due to this heads alignment, or possibly
a worn switch roller.

On 02 Jan 2005 10:14:08 -0500, Sam Goldwasser
wrote:

writes:
If no one messed with the A/C adjustments, they haven't changed on their
own!
Obviously. I'm responsible for it being moved, for reasons that
are besides the point. I've got it back into a reasonalbe
position. No tracking problems, and good audio from the mono
head.

First try cleaning the pinch roller very thoroughly. If that seems
to help, replace it.
The pinch roller is shot. I started cleaning it and it's
crumbling before my eyes.
Now, the tape is being driven up slightly by this roller,
resulting in a small tape crease on one of the guides.

Where can I get a new roller. Any sources?
I'll call
http://www.partsolver.com/Default.asp
It looks like they have a bunch of parts for this model
(slv-798hf).

regards,
Dave

On Saturday, 01 Jan 2005 23:00:00 -500, "Asimov"
wrote:


Dave, it's never supposed to ride over the edge, only beside it. The
AC head isn't supposed to change top or bottom tension but if the tape
path is wrong then it might. I would suspect wear or an improperly
sitting load arm. Don't mess with the AC unless you are sure the path
is good. I bet you will find it to be okay then.



... This message transmitted on 100% recycled photons.
Hi A*s*i*m*o*v
thanks for the info.
Video and hifi audio alignment is perfect, the two roller guides
that align around the drum have never been moved.

The main problem I have is actually the rubber pinch roller;
I'll have to find a replacement (any sources appreciated)
I seem to have realigned the A/C head to a reasonable accuracy.
cheers,
Dave

Dave

After replacing the pinch roller, assuming you find one,
then DO set the azimuth accurately for maximum treble
response when playing a pre-recorded tape in mono lo-fi
mode. If the azimuth is out, recordings you make will
sound horrible on other non-hifi machines, and anyway
you can cause the control pulses to be poorly recorded
causing yet more problems.

The tape riding up as you describe is a common symptom
of a ruined pinch roller.

Colin (www.colin99.co.uk)

davexnet02 wrote:

On Saturday, 01 Jan 2005 23:00:00 -500, "Asimov"
wrote:



Dave, it's never supposed to ride over the edge, only beside it. The
AC head isn't supposed to change top or bottom tension but if the tape
path is wrong then it might. I would suspect wear or an improperly
sitting load arm. Don't mess with the AC unless you are sure the path
is good. I bet you will find it to be okay then.



... This message transmitted on 100% recycled photons.

Hi A*s*i*m*o*v
thanks for the info.
Video and hifi audio alignment is perfect, the two roller guides
that align around the drum have never been moved.

The main problem I have is actually the rubber pinch roller;
I'll have to find a replacement (any sources appreciated)
I seem to have realigned the A/C head to a reasonable accuracy.
cheers,
Dave

On Mon, 03 Jan 2005 19:56:09 +0000, Colin McCormick
wrote:

Dave

After replacing the pinch roller, assuming you find one,
then DO set the azimuth accurately for maximum treble
response when playing a pre-recorded tape in mono lo-fi
mode. If the azimuth is out, recordings you make will
sound horrible on other non-hifi machines, and anyway
you can cause the control pulses to be poorly recorded
causing yet more problems.

The tape riding up as you describe is a common symptom
of a ruined pinch roller.

Colin (www.colin99.co.uk)
Thanks for the info Colin,
I will indeed endeavor to properly align the azimuth once
I get the pinch roller replaced.
I've located it at www.partsolver.com for $20 - could be worse.
Cheers,
Dave

On Saturday, 01 Jan 2005 23:00:00 -500, "Asimov"
wrote:

"davexnet02" bravely wrote to "All" (02 Jan 05 01:57:24)
--- on the heady topic of "how to adjust the staionary control track/mono audio head ?"

da From: davexnet02
da Xref: aeinews sci.electronics.repair:5552

da Hello all,
da I'm trying to realign this VHS vcr head without any special
da equipment. It has three adjustment screws,each on springs.
da One in the front, to control the front height, and two at
da the back (like a triangular arrangement) to control the
da back height / azimuth angle.

snip

Dave, it's never supposed to ride over the edge, only beside it. The
AC head isn't supposed to change top or bottom tension but if the tape
path is wrong then it might. I would suspect wear or an improperly
sitting load arm. Don't mess with the AC unless you are sure the path
is good. I bet you will find it to be okay then.

A*s*i*m*o*v

... This message transmitted on 100% recycled photons.
Hi A*s*i*m*o*v
I realigned the A/C as best as I can. I'm observing
reasonable production of the mono audio track, and
no obvious control track errors.

One thing that seems flexible on this head is the absolute height.
Just made a guess on this; I think I left it slightly higher than it
was.

I actually fixed the old rubber pinch roller - at least till I
can get it replaced. I ended up filing it down with a nail file,
until the crud was off and it was even as best as I could get it.

regards,
Dave