Issues capturing VHS tape over SDI?
 

Hello friends,



I recently purchased a Panasonic AG-6500 Professional VCR for the purposes of capturing/archiving video via SDI. However, I have been unable to properly get a signal and am asking for someone to point out what I am doing wrong.

On first hooking up my Panasonic unit and capture card through SDI cable, I got no signal. I attributed this to the fact that the Panasonic unit has a 50 Ohm SDI output and my Blackmagic Capture Card has a 75 Ohm input (and I was using a 75 Ohm cable). I then purchased a 50 Ohm to 75 Ohm converter hoping this would solve the issue. Still no signal. Thinking that maybe the SDI input on my capture card could be broken, I purchased 3 different SDI to HDMI converters (from three different companies), including BlackMagic. I tried converting it to HDMI, as I knew the HDMI slot worked on my capture card. Still no signal either to the capture card or to a TV.



Can someone tell me what I'm doing wrong? I purchased a SDI to RCA Female adapter, connected it to a monitor, and confirmed that the unit itself is functional. Please let me know if additional photos would be helpful.

Are you sure the AG-6500 has a working SDI output?
SDI = serial data interface, a digital communications standard initially issued in 1989.
As a point if interest the AG-6500 dates to 1988.

It appears to me the AG-6500 only has a composite analog video output.

As a quick test you could try connect the video output you are using to the composite video input on a TV and see what you get. But it sort of sounds like you did that already. Was what you describe as an SDI-to-RCA really a BNC-to-RCA adapter?

Here's a view of the back on the Panasonic unit. I'm using the video outputs in the middle. And yes, on Amazon, the item is listed as BNC to RCA Female.

Here's a view of the back on the Panasonic unit. I'm using the video outputs in the middle. And yes, on Amazon, the item is listed as BNC to RCA Female.

I highly doubt that's a digital output, Video out in the picture is composite, so use your BNC to RCA to connect to your capture device's composite input.

^+1, That would normally be a composite video output, unless someone has gone to a lot of trouble to modify the machine.

SDI terminals normally use a BNC connector, as do video connections on professional and industrial gear. The SDI standard is 75 ohm impedance. (FWIW: many of the Panasonic devices had 50 ohm output impedance on their audio outputs.) The "DOC" terminal may be for related to drop out compensation, but you would have to check the manual on that.

A capture device with composite video input is likely what you need and other threads here make recommendations. If you really want to capture via SDI input you would need a device like the Black Magic Design Analog to SDI Mini Converter.

What make/model capture card and software are you trying to use?

It maybe confusing to some people to why pro gear use the same connection for both old analog composite and new digital SDI but the reason behind it is purely economical, When studios started to convert over to digital, equipment manufacturers decided to use the same BNC connectors to make it easy on them by just swapping the gear and using the same cables, this can saves money on buying new expensive cables and saves time by avoiding complicated installations.

It also boils down to the quality of the resulting connections. Unlike RCA and s-video connectors, BNC do not easily separate accidently providing a secure and are generally a more weather-proof connection. They are better at preserving the impedance of the circuit, important for longer runs.

They are also typically used for component video connections, house sync, and other signals. XLR (Cannon) connectors or 1/4" phone plugs are often used for audio in preference to RCA. RCA's are used in consumer gear because they are a low cost solution.