Current arrangement has 7 bullet cameras, which will increase to 9 shortly. Checked he current drawn from the 7 cameras yesterday and its 770mA. The current linear regular power supply delivers about 9.5V. The output voltage is adjustable and the cameras work fine at this voltage.
http://www.cameras-cctv.com/Bullet_camera_21EH-R43
Cameras are all this type.
Bought one of these as I wanted fused outputs
Weishuo 12V 10A DC 9 Output Power Supply Box Switch Mode CCTV Camera Distribution Power Supply https://www.amazon.co.uk/dp/B07SV1W15G/ref=cm_sw_r_apan_glt_i_S7XGRA3XDTYD0EY14KC0?_encoding=UTF8&psc=1
Interference is worse with new supply.
Also was thinking about powering two PIR 12 volt security lights from this supply. However, I reckon that the jolt to the power supply of switching in/out in a 1 Amp/12v security lights will cause Interference with the cameras, if it all comes from the same psu. Will check this in the coming days.
Thanks for the recommendation of psu supplier. They are US based and I am EU based. On this side of the pond it is CE mark.