Two LTBCs in a row. Is it good, bad or just doesn't matter?

[fabweb]

I have a Canopus ADVC 300 which has a LTBC.

My SVHS also has a LTBC. (JVC HR-S9600)

Should I use only one of them?
Do they enhance each other or do they hinder each other?

[davideck]

Using both should be fine. The JVC will provide the timebase correction and the Canopus should simply lock to the stabilized video from the JVC.

[fabweb]

I made some interesting observation digitizing the same footage with BOTH LTBCs on and with the ADVC LTBC only.

If I have both switched on the there is jitter all the time. If I swith off the JVC LTBC the picture is stable till one point, where it breaks down completely.

(only applies to problematic footage)

I am not sure which sittuation is better, but they do behave differently.

[edDV]

The ADVC-300 has a narrow correction range. I'm not sure it was intended for loose consumer VHS machines.

[davideck]

If I have both switched on the there is jitter all the time. If I swith off the JVC LTBC the picture is stable till one point, where it breaks down completely.

Are you talking about vertical jitter (jumping up and down)?

[fabweb]

Yes. the jitter is up and down.

[davideck]

Then it sounds like the VCR is having difficulty recovering the Vertical Sync Interval off tape and neither TBC can detect it reliably.

Have you tried the Video Stabilizer option on the JVC?

[Wile_E]

I have Canopus ADVC-300 and JVC HR-S9911U S-VHS VCR. I leave the line-tbc enabled on both units and it works fine. No jitter at all.