What type of cord is this and where can I buy it?

https://imgur.com/a/SRZUy79 - the cord

I'm trying to find the original A/V cable for my Sony Handycam CCD-TRV98 and in the manual it said the A/V went into the A/V OUT a 3.5mm mini jack and the A/V IN was just a yellow and black cord (yellow for video, black for audio) I tried using the typical A/V cord with a 3.5mm mini jack to the yellow, red, and white cords but it resulted in a buzzing noise. I'm assuming this is an old type of A/V that takes the red and white cords and combines them into one black cord. Any help finding this would be appreciated, thank you.
I looked on Ebay and found used Sony Handycam CCD-TRV98s for sale used.

I would guess that it uses a three conductor 3.5mm jack not a four conductor. I would also guess that a standard stereo jack could be tested swapping them into the RCA for video to determine which chanel is video.

Three conductors jacks share a common ground.

If you only have two jacks coming out of mini jack just try flipping the connection and see if you get a picture and sound.  If you have three coming out there are only 9 combinations shouldn't take long to figure out.
BTW the color of the connectors has nothing to do with the signal.  If there are two jacks coming out of it that means there are only two signals to go into it.
I got a 3 conductor 3.5mm jack to 2 rca male and audio now works perfectly. Thanks for all the help.
Walmart would have it 
bring $5 with you