#Targa+ to Panasonic 7750
23 messages in this thread
I'm having trouble with flicker/distortion in the upper right hand corner of
the screen when I play a tape. This tape was made with my Targa+ and Panasonic
7750. If I turn on the TBC in the 7750 the problem goes away. All my equipment
was bought in Sept 1991 and was wondering if maybe the Targa needs to have a
tune-up.
Thanks for any help you might be able to provide, I would like to fix the
problem before it becomes critical.
Regards………….Rick – Technical Animations
Rick,
>> I'm having trouble with flicker/distortion in the upper right hand corner of
the screen…. <<
Sounds like your AG-7750 needs a tune up not your Targa. This could be a
tracking problem or tape alignment problem, that the TBC is correcting for.
John
John,
>>Sounds like your AG-7750 needs a tune up not your Targa. This could be a
tracking problem or tape alignment problem, that the TBC is correcting for.<<
When I play back an older original tape I have no problems and changing the
tracking while watching a tape with a problem provides no help either. I
thought maybe the Targa had a problem with its sync signal. I suppose the
AG-7750 could have a problem on the record side, but not the play back side,
what do you think?
Regards……….Rick – Technical Animations
Rick,
It probably would be easier to put the Targa on a scope and check its black
burst etc. I'd go through and clean the pinch rollers and guides on your
AG-7750. Check the cable connections. Sometimes the wieght of the cables can
cause some of the solders to become weak on the Targa cables, especially if
they've been swapped around. Check the connections of the Diaquest, if that's
what you're using. Double check the switch settings on the AG to make sure
they're in the right position. How long have you been using this deck and
Targa combination? If its been awhile and you know this equipment well, then
your assessment is probably correct.
John
John,
I've been using this combination for 3 years now. I'm the only one that uses
it, therefore swapping of the cables does not happen very often. Maybe 10-15
times in the 3 years. I'm using the BCD-5000 controller in my system.
Thanks for the help. I think what your saying is check and clean everything I
can think of first then spend some money <BG>.
Regards………Rick – Technical Animations
Rick,
>> check and clean everything…. then spend some money <BG>. <<
That's correct. <g> With the thought that checking out the Targa is fairly
straightforward. If you can get access to a Waveform monitor and hook up the
output sync, you can see whether or not its in spec. before you ship it out.
After 3 years its a good bet your AG-7750 needs a tune-up anyway.
Hope you get lucky, 🙂
John
John,
When you say clean the connections, do I need some kind of spray cleaner or
will just reseating all the connectors suffice?
Thanks for your interest!!
Regards………….Rick – Technical Animations
Rick,
Typically, I'd do a visual inspection of all the connections. Pull off the
cables look at the core pin, reseat etc. In the case of Targa cables I'd take
off the covering and look at the solder joints, if you can. If anything
required cleaning, I'd use a can of WD-40, its great on electrical parts, and
remains conductive. I doubt your problem is in this area but it never hurts to
check. Especially the sync cable, which if anything is the most likely culprit.
Hope this helps.
John
John,
Thanks for your input, it always good to have another view of the problem. See
my message to Paul Minni if you have time, I'm thinking that the BCD-5000 video
controller might be the problem.
Regards………….Rick – Technical Animations
Rick,
You may be onto something. All things considered, not the worst thing that
could happen. Unfortuneately, I have little to no experience with the BCD, they
were pretty popular several years ago. I used Lyon Lamb in that time frame. If
it comes to repairing it you might just be better off buying SoftVtr or
Animation Commander at about half the price. Course you hang around here long
enough and someone will try to talk you into buying a PAR. Not me, I still like
tape but I've been known to use one. <g>
John
John,
I talked with BCD and they said it could not be in their equipment, but they
recommended someone who works on their 7750. BCD is just across town from me,
thats one reason why I bought their equipment. I should get my 7750 back this
afternoon, they are performing an editing & servo alignment. The bad thing
about all this is they can't tell if they have fixed the problem, since they
don't have system to test it in. I'll have to pick it up and test it myself,
then on to the next step if its not right.
PAR, Oh I wish I had the time to play golf.<G>
Regards…………Rick – Technical Animations
<<<I'm having trouble with flicker/distortion in the upper right hand corner of
the screen when I play a tape… All my equipment was bought in Sept 1991 and
was wondering if maybe the Targa needs to have a tune-up. >>>
Does this occur with other video sources(bars, camera, etc.) or just
with the T+? If it does, this maybe an early sign of VTR head wear.
If the heads are new or have low usage hours, maybe a recent change
in tape stock could be causing excessive wear.
Just a thought,
Paul
Paul,
>>Does this occur with other video sources(bars, camera, etc.) or just
with the T+? If it does, this maybe an early sign of VTR head wear.
If the heads are new or have low usage hours, maybe a recent change
in tape stock could be causing excessive wear.<<
I tried hooking up my camcorder for an input then grabbing images from it. I
still had a similar problem, yet it was exactly the same. I suppose that kind
of eliminates the Targa+. The only other possibility could be the BCD-5000
video controller, maybe? I have always used Fuji H471S tapes.
I just purchased all the service manuals a month ago for the Panasonic AG-7750
and found out how to get the "Drum on total time" and "Capstan in total time",
they are 530 hrs and 245 hrs. I'm going to clean the heads and if that don't
help then I will take it in for further testing.
Thanks Paul for the help, I know very little about the video side of this
business and any help is greatly appreciated.
Regards……………Rick – Technical Animations
Rick,
<<<I tried hooking up my camcorder for an input then grabbing images from it. I
still had a similar problem, yet it was exactly the same. >>>
Does this problem occur without going through the T+ (connecting the camcorder
directly to the VTR and recording)? If so, does the problem follow to another
VTR upon playing the tape in a different machine? If it does the problem could
be isolated to the record head. If it doesn't, it may be the playback head on
the "original" VTR.
<<<The only other possibility could be the BCD-5000 video controller >>>
It's highly unlikely that the BCD has anything to do with it…
<<< I have always used Fuji H471S tapes. >>>
Maybe Fuji changed tape formulation. This could hard to find out, though. But
it does happen…
<<<I'm going to clean the heads and if that don't help then I will take it in
for further testing. >>>
Not to sound condesending, but you know how to clean video heads? They
are very delicate. A good lint-free cloth, like Texwipes, and freon
are a good choice. 97% Isopropyl Alcohol works well and is more economical.
Avoid the Q-tip method for general cleaning. A damp cloth applied with slight
pressure while manually turning the scanner will do the trick and is
potentially less damaging.
Another possibility comes to mind. I used to work with JVC VHS editors at
university and in these particular machines the had a brush assembly
that "contacted" to the scanner assembly. The brush looked like metal
"fingers" that touched the center spindle of the scanner. This spindle is like
an axle and the head assemblies on the scanner revolve around it like a wheel.
Basically, an induction motor. Anyway, after much use
the brush fingers would become phyiscally shorter and make poor contact
with the spindle and "brush noise" would be the result. Changing the brush
assembly would correct this problem. Something like this could be what you are
seeing.
In a nutshell, I think you have the right idea by having a service tech check
the VTR out.
Paul "Not a real Engineer, 'just play one at a TV station" Minni 😉
Paul,
I cleaned the heads with a Wetswab from Texwipe, this was of no help. I know
you doubt that the BCD could be the problem, but I'm beginning to suspect the
BCD-5000 video controller.
Tests done w/BCD (frame by frame) and all have a problem:
* Laid images to tape using Targa S-VHS input to the 7750.
* Laid images to tape using Targa VHS input to the 7750.
* Grabbed images using camcorder as input to the 7750.
Question, would the problem be on all Targa outputs?
Test done w/o BCD (not frame by frame) with NO problems:
* Copy tape played in Panasonic Ag-1960 to 7750 using the video insert mode.
* Used camcorder as input to 7750 while in the video insert mode.
* Targa out to the 7750 and recording in the video insert mode.
****************FROM PREVIOUS MESSAGE*****************
Rick – I'm going to clean the heads and if that don't help then I will take it
in for further testing.
Paul – Not to sound condesending, but you know how to clean video heads?
I do, I did. Did you read the message?? <GD&R>
Regards………….Rick – Technical Animations
Rick,
<<<I do, I did. Did you read the message?? <GD&R>
I did, but I've read so messages lately… forgive me (g)
Well, it does seem the BCD is part of the equation. Refresh my memory, I
haven't work with one since my school days, does the BCD require an external
sync signal? If it does, what are you feeding it?
<<< Question, would the problem be on all Targa outputs? >>>
If the T+ is in external genlock mode and the sync signal is *funky*
then T+ would most probably show the problem on both video outputs(comp. &
S-VHS).
It's difficult to judge what's really happening without looking at a
waveform monitor. When you playback the tape can you *see* the problem on your
waveform. Is it limited to just the color portion of the signal? Does the
colorburst do strange things at the edit point(ie. become unstable)?
Also, what happens when you use the BCD to record several seconds of video in a
single edit(If I remember correctly, the BCD came with a BASIC-like program
that would allow you to do this).
Without seeing it on the 'scope, ya got me stumped,
Paul
Paul,
>>Refresh my memory, I haven't work with one since my school days, does the BCD
require an external sync signal?<<
It takes video in/out, but not a single cable specifically for sync.
>>When you playback the tape can you *see* the problem on your waveform. Is it
limited to just the color portion of the signal?<<
I don't have a waveform monitor, I wish I did. I think its in the horizontal
area between frames and not in the color portion of the signal. BCD called the
problem "flagging".
>>Also, what happens when you use the BCD to record several seconds of video in
a single edit.<<
I think its ok then, well maybe its not the BCD.
I have taken the 7750 in and they are going to perform a editing & servo
alignment, then I will have to bring it home and test it to see if that fixed
the problem.
Regards…………Rick – Technical Animations
Rick,
<<<I have taken the 7750 in… then I will have to bring it home and test it
to see if that fixed the problem. >>>
So how did you make out?
Paul
They found a service bullentin that looked like it would fix my problem with
the VTR. They performed the update and cleaned the tape path, but that didn't
help. Next they came out to my office with their waveform monitor and vector
scope etc. They think that it has something to do with the erase head timing.
The Targa is definitely OK, that was good news because Truevision wants $250
and 2-3 weeks to recalibrate. Thats where I'm at now, just waiting for them to
give me a call to pick up the VTR.
Thanks for asking how things are going, I will let you know if it works when I
get it back.
Regards……………..Rick – Technical Animations
Rick,
Sorry to hear you've had a time of it with your VTR, but it does sound like
you've got some competent people working for you. I'd like to know how it is
finally resolved as well.
John
<< They think that it has something to do with the erase head timing. >>
Makes sense. Hopefully that's it and the parts are in stock…
Once again, Good Luck,
Paul
Paul,
Thanks for the good luck wish, I will let you know what the final outcome
is….. when it happens.
Regards…………Rick – Technical Animations
Paul & John,
I got the Panasonic back and ran the usual test, which this time it seems to be
fixed….huraaah!
This is what they did the 2nd time in the shop:
* Performed a complete edit servo alignment (they stopped last time when they
found the service bulentin).
* Minor adjustment to the servo PG phase shifter.(What ever that is?)
* TBC lock phase adjustment.
* They suggested that I do edits 3 frames at a time, but only increasing the
editin point by one. This will give a cleaner signal at the exit of the frame
I'm editing.
If you remember they came out to the house for 2 hours then took the VTR in for
the above service. They only charged me additional $27.50, not bad at all I
thought. The total charge was $110.
Thanks for hanging in there and giving me your suggestions, it was very much
appreciated.
Regards……………….Rick – Technical Animations