Pt2399 Delay Time Sync

[jghfslk]

I have been breadboarding a circuit with the hopes of using PT2399 chips in series to get long delay times similar to the Deathklaw, Sagan Delay, etc.  I'm having an issue getting the delay chips to each have the same delay time.  I currently have it set up like the Deathklaw current mirror section of the circuit.  The longer I have the delay time set, the more the delays don't seem to be synced with each other.  If I have a delay time of 300ms at the first chip, I would think I that I should get another 300ms from the second totaling 600ms.  Instead the longer the delay time is from the first delay, the second delay gets much longer than the first delay.  For example, if delay 1 is at 200ms, delay 2 is 300ms totalling 500ms.  If delay 1 is at 300ms delay 2 is at 900ms, totalling 1200 ms.  If delay 1 is at 500ms, delay 2 is at 2000ms totalling 2500ms.  These are guesses of exact delay times but I can't think of a better way to describe my issue.

I have built both the Deathklaw and Sagan delay and neither behave this way which makes me think I'm messing something up but I have checked things over and over and started from scratch and keep getting the same result.

If anyone has any suggestions I would really appreciate them!