Yashica Electro 35 Simulation 

This Simulation shows effect of main capacitor & battery voltages.




The graph above shows the simulator output for a Cx of 2.2uf and battery voltage of 6v.
The circuit used for the simulation is shown below:-

Why Simulate?
My yashica 35G camera was not working correctly, it was found that the main capacitor needed replacing.
The original 5.6V battery presented a problem since this was no longer available.

Due to these reasons I needed to find the effect of different battery voltages to see e.g. if a 6V
replacement was suitable. Also a correct value for the main capacitor was needed, the original
value was not available as a single component.

Description of the circuit:- The chain of resistors provides the aperture control functionality.
Here the Rf resistor (15k) is charging the main capacitor C1, battery voltage is 6V.
This design is based on the original Yashica 35G schematic with the shutter / transistor arrangement
being more modern as probably found in the GSN.


Table showing relationship of the main capacitor Cx and battery voltage.
Cx
5.6v (original)
6V
4V 
1uf
1/74
1/72
Not tested
2uf
1/37
1/35
Not tested
3uf
1/25
1/24
1/29
4uf
1/18
1/18
1/22
CONCLUSION
Choosing a replacement tantalum (10%) capacitor @ 6V  Shutter Speed (Simulated) Comments
2uf 1/35
2.2uf 1/32 Best option, but test with a shutter tester!
2.7uf 1/26

Information provided here is to the best of my knowledge assuming the simulation was correct :-)
no account for mechanical delay has been included in these results so take them for what they
are, a guide at best. No two cameras are the same, so it is best to check with a shutter tester
if you suspect the main capacitor is faulty.