Hi everyone,
I recently pulled my GMC-320S out of storage after not using it for almost two years, and I’m noticing that the CPM readings seem slightly higher than what I used to get in the same environment. Before I assume the tube is drifting, is there a reliable method to verify whether the CPM readings are still accurate?
For example:
Is there a recommended low-cost check source or calibration reference for home users?
Does long-term storage affect the M4011 tube’s baseline readings?
Should I perform any internal reset or firmware check before testing accuracy?
Thanks in advance for any guidance! |
Checking GMC-320S accuracy after long storage
Posted - 11/21/2025 : 23:21:49
