How do I remove white streaks?

[fusebuster]

I am converting some old tapes with a newly purchased ADVC-300. I am getting intermittant horizontal white streaks on the output that I would describe as comet shaped. There is no pattern even on a redo. I am using a fairly new, good quality, 4-head playback machine with self-cleaning heads. I do not have this problem with new tapes.

I found a post in a video forum that says these streaks are caused by either dust or holes in the tape's emulsion. I have cleaned the tapes, and since the steaks don't have any pattern, I don't believe it is due to holes. The post said that "drop-off compensators" are used to fill in the missing data. Further reading says that TBC should be doing the same thing.

So...I am wondering...should the 300's TBC be correcting these white streaks if they are due to drop-off? Also...are there settings in the software panel that will remove these? If not...then how can I remove the streaks?

[Markus K.]

Could you post a screenshot?

[GrassValley_BH]

One thing to check first... Do you have a loop in the signal? In other words, VCR Out -> ADVC In
ADVC Out -> VCR In

Sometimes this can cause signal timing problems.

[fusebuster]

No loop...my setup is VCR out (RCA) > ADVC IN > Firewire out to computer > Scenalyser capture utility. I am using shielded cables...and...none of the signal cables are in contact with power cables.

I have pointed to two of the "comets." They move left to right on a horizontal path. They are also much brighter than I was able to capture. If this doesn't give a good look at them, I can crop in closer if that would help. I have been able to eliminate most of them with post-processing noise filters...but not enough. I am thinking that TBC should be doing the correcting?

I will add here that I am using a newly purchased 300. I upgraded from the 100, and didn't see these streaks there...using the same original tape. The quality of the 300's output is significantly better in terms of color depth and detail, however.

[antonsvideo]

these are tape dropouts

only some TBC's are equipped with Drop Out Compensation

The Best DOC and TBC is built into the Sony SVO 5600 and 5800 S-VHS/VHS player models, maybe you can hire one for a day

if tape format is other than VHS, let me know and I suggest something

[GrassValley_BH]

I agree with Anton - definitely looks like tape dropouts.

[fusebuster]

antonsvideo...many thanks. I have both PAL and NTSC VHS tapes, and these Sony's seem to be NTSC machines. I didn't see anything in the Sony line that appeared to be multi-format...so I am welcome to any suggestions. Also, I am using a Samsung SV-5000W multisystem machine...and I am wondering if I could feed the signal through one of these Sony machines to clean the signal? I didn't see anything in the specs one way or the other about this.

I also tried to find a standalone TBC/drop off "black box." Any suggestion here would be also appreciated. I am not having any luck with the search engines.

It sounds like drop off compensationn works in fundamentally the same way that TBC does, and so I am also wondering if there is anything in the Canopus line designed for drop outs?

Grasping at straws here...I am also wondering if a cheaper 2-head VHS player might not be sensitive enough to pick up the drop offs?

[Tobe]

if you look for "drop-out compensator" you'll have better luck. Most stand-alone Time Base Correctors have this feature built in...maybe you can rent one for the job. they will only clean up a certain amount of "drop out"...depends on how bad the tape surface is.
Tobe

[antonsvideo]

in order for a standalone TBC to really detect a dropout, it needs to be connected to a tape machine with RF off tape connector

I have the Sony-SVO5800P (Pal) for VHS or S-VHS capture, nothing beats this machine (I don't know any VHS machine suitable)

if you can get an NTSC and Pal model on ebay, get it, most users are selling them cheap due to digital technology

also, I assume you use Edius, try a small amount of motion blure after capture, this may hide the dropouts

[fusebuster]

Anton...I will be on the lookout for the Sony SVO-5800P.

Could you explain a little more about the comment "in order for a standalone TBC to really dtect a dropout, it needs to be connected to a tape machine with RF off tape connector"?

[7hbg]

Could you explain a little more about the comment "in order for a standalone TBC to really dtect a dropout, it needs to be connected to a tape machine with RF off tape connector"?

The simplest explanation is that analog video on tape is recorded on a RF carrier. While playing the tape, when a VTR encounters a dropout, that carrier is not present (gone). If that information (RF carrier) is available to the TBC, then it knows that at that precise point it should substitute the picture with something to cover the dropout. It is a necessary part of the ‘dropout detection’.

[antonsvideo]

exactly as Rob said!

[fusebuster]

The explanatilon about the RF carrier signal makes sense. I am a little confused about the last part though about "a tape machine with with RF off tape connector."

Does this mean that there are VTR's that have an "extra" port where a "raw" RF carrier signal is output?

[7hbg]

Does this mean that there are VTR's that have an "extra" port where a "raw" RF carrier signal is output?

Yes it does (BNC connector on the left):



But don’t confuse it with the old style ‘RF output’ (CH2/3 in US) 'F' connector.

[fusebuster]

Thank you for posting the pic...it's worth a thousand words!