Old TV as a ZX80 monitor may not be optimum

[Creator]

I've been trying for some time to get my ZX80 to play properly with my ZX8-CCB (they won't). I know this works well for many & I'm confused why it's not working for me.

After many alterations I've returned the ZX80 back to its original config except R30 which is now 100, R33 5.6k, R31 1k, R32 not populated (sync path is thru R36 5.6k & TR1). This config gives the best image using the original RF modulator.


Attached is some relevant info, I'd appreciate your comments (especially for the ZX8-CCB developer)

img 702 For reference, image thru original rf modulator (dark bar at bottom not actually there)

img 701
ch1 1c2.4
ch2 1c4.4
ch3 output of original rf modulator - nothing connected
ch4 output of ZX8-ccb TV connected thru

img 703 Same data as img 701 - time base expanded

img 710 Same data on screen, image thru ZX8-CCB Best image after adjustments (dark bar not actually there, scope probe disconnected)