Rebuild CRT B/W monitor

[MrWifiHifi]

Hi

I recently got 3 5.5" (14cm) crt b/w monitors, but they don't seem to work properly, they work but not like they should
Is there a way, I can somehow build my own CRT b/w tube controleror drive board to use them and display composite video on them (NTSC,PAL) ?

I would like to use these small crt's as a vintage computer monitors, or somthing like apollo terminals 

CRT monitor models:
1.EASTERN EBM-50
2.HS-80
3.EU-5775

I would be really thankful for any help

[Renate]

Wouldn't it be easier to just make them work as originally intended?
What do you mean that they "don't seem to work properly"?
Have you checked the scanning rates?
Photos of screen? Boards?

[strawberry]

B&W CRT not need composite converter for NTSC/PAL/SECAM.. just plug single video wire and watch if framerate is right for a monitor
If you want to connect to regular PC, convert Hsync frequency 24kHz and even higher to 12kHz(otherwise you will get two squeezed pictures on the same monitor or out of sync) for crt then level and sum all Vsync Hsync  and RGB and feed in to regular video input or find where to connect directly
Or buy VGA to Video converter
If the problem is faulty monitor replace elec.capacitors and/or adjust Vsync Hsync H/V size pots...

[Renate]

How about buying a couple of these and putting them on an HDMI output from your PC?
https://www.ebay.com/itm/HDMI-To-RCA-AV-Adapter-Converter-Cable-CVBS-3RCA-1080P-Composite-Video-Audio-US/293583863451