Converting PAL CCTV to output NTSC - Page 1
Forum section: electronics / projects

author: mklivoslov
author_rank: Newbie
timestamp: March 21, 2025, 10:48:39 pm
content: Greeting to all,I'm having struggle figuring how to converting the wholesale PAL CCTV to output NTSC CVBS signal for a US lab equipment.Background: The camera in a chem lab meter outputs giberish after sitting in storage for about a decade. Since there would be a quote on the camera from the manufacturer, along with the 1-month delivery delay (not to mention crumbersome customs), I've decided to just source a replacement locally after gathering enough information about how that camera works.So I bought these used CVBS PAL camera from a wholesaler (no premium of free e-waste here), and extracted only the camera board. Luckily it had the same footprint as the camera in the equipment.Searching for the datasheet for the main IC (big one underneath the sticker, P/N: NVP2020), I found one: this processor can output PAL or NTSC, as long as:- The correct crystal is used;- And I flip that one NTSC bit to one.Salvaged an NTSC crystal (it's really rare!), managed to desolder the EEPROM and program that NTSC bit without knowing its part number (L16 or 8003W or whatever, only that it can store 2 banks of registers for the processor or 0x200 bytes in size), the equipment could now show the signal without flickering.Just one problem: There's a ghosty band on top of perfectly good image!I've spent few hours trying to erase this: changing some registers to default; should I change the horizontal timing; cloning some more defect registries; etc.It's a rut, and there're many things I don't know about:- How these registers affects timing, what unit is it on?- What are defects?I even desoldered the CCD to get its P/N (ICX409AK) to get the timing, but banging my head against the wall here.I really hope to know:- There're any references on these digital processing?- How can I map these values to delete that ghost bar?I think the PCB can only hold so much desoldering...73,Maurice.P.S. Some images attachedP.S.S. I got the processor datasheet here:https://www.fscctv.com.tw/blog/CCD_DSP/Nextchip_NVP2020.pdf.But just in case, I've also attached it.

author: Benta
author_rank: Super Contributor
timestamp: March 21, 2025, 11:36:39 pm
content: I'm sorry, but I think you're into wishful thinking here.The IC will support NTSC or PAL CCTV cameras.It will NOT transcode between the two formats. So if the camera chip is PAL format/timing, it will stay that way.

author: mklivoslov
author_rank: Newbie
timestamp: March 22, 2025, 03:05:43 am
content: OK, I just did another round of datasheet reading.So the processor does support NTSC, but I have to replace the CCD sensor to NTSC type as well... but one can hope.At least now it no longer flickers when used with the equipment, and miles better than that dead one originally.Really hope that the processor has line clipping function though.73,Maurice.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 26, 2025, 05:58:32 pm
content: Try out the nasty little analog to HDMI, HDMI to analog boxes, one of each as found on Ali, amazon etc. CAD10 to try that out.Drop "Black Box" a line and see if they think a pair ofhttps://www.scan.co.uk/products/blackmagic-mini-converter-updowncross-hdrunning back to back will work. They ough to.Other analog/ SDI converters ar available of course.Analog video scan converters and scalers are a thing of the past but you never know. "Seamless switcher" may still be the answer.To my shame, I can admit that I binned quite a few (medical grade no less) units. I've still got my trusty Kramer SP-10DCheck ebay for "video standards converters".Maybe Drop Extron etc a line and let them exsanguinate you.