Thermostat for incubator

I was wondering if a Ranco or Johnston thermostat would work good for an incubator as i cant afford a herpstat right now or would it be better just to save up and get the herpstat.

For an incubator Id get a Herpastat or a Helix. You want a proportional for the incubator. But remember that in a sence your putting all your eggs in 1 basket.

The 2 best thermostats for any incubator are going to be a basic Herpstat or a Helix Basic. Non proportional thermostats like Ranco and Johnsons will bounce your temps around too much. You want one that's going to keep a steady temp as close to a .5 degree swing as possible.