That should work, but you may run into an issue finding perfect cap values to replace them with.
Let me run a simulation real quick… (time passes)
This is directly from the Cadet IV’s schematic (The H-rate section). The trimmer (R1) is for adjusting the ramp’s peak to exactly 1V.
If I change the sync rate from 15.734KHz to … 33.75kHz, then a cap of about 22nF to 24nF results in close to a 1V peak. 24nF is about the highest you should use since the tolerance of any given ceramic cap might be 10- or 20% higher.
Tayda has 18nF and 22nF ceramic caps, so it should be easy to find one that fits. The trimmer, R1, should let you trim it to 1.0V even if you’re use the 18nF cap.
Changing the cap is the easy part. Getting the HD sync pulses on a 14-pin ribbon cable will be more difficult. @joem may be working on this though.
The timing cap will still work. You will just be limited by fewer bars. Changing the cap with the ratio we used above should get you fixed up.
EDIT:
I corrected the H-rate pulse width in my simulation to 525nS as listed in the LMH1980 datasheet. This changed the perfect cap value closer to 27nF. 18nF should still work since the R1 trimmer allows for such a wide range of attenuation.
