Lifespan Breakdown

• Datasheet Rating: ~5,000 hours minimum (conservative manufacturer specification from the Soviet era).
• Real-World Use: 15,000 to 25,000+ hours (often translating to 5 to 10 years or more of normal service).
• The Mercury Advantage: IN-14 tubes are mercury-doped (identifiable by a slight violet/purple tinge when lit), which classifies them as "long-life" tubes and helps them resist degradation better than undoped models

Common Factors Affecting Longevity

• Cathode Poisoning: Unused digits can develop a coating that prevents full illumination. Good clock circuits prevent this by periodically cycling or "slot-machine scrubbing" through all the numbers. 
• Operating Current: Running tubes at a lower cathode current extends their life significantly, as wear increases exponentially with higher current. 
• Age and Handling: Because these are New Old Stock (NOS) manufactured decades ago, microscopic cracks in the glass-to-pin seal can occasionally cause slow air leaks, leading to premature failure regardless of use hours. 

It's when a tube stays on the same number for months and that number gets dim. Our clocks automatically cycle through all digits every few minutes to prevent it.

No matter how long you have the clock I will take care of you. I send instructions if you want to change anything. You will have my phone number and email for questions.

Up to 90 days you have a problem you send back I will fix it and pay postage back to you.

Up to 6 months you send back. I will fix, you pay for, at cost, parts and you pay postage back.

Rarely does anyone have to send a clock back. I stand by my product. 

I don't take returns or do exchanges. If you like another clock I will sell it to you at a discount for being a repeat customer.

Since I became disabled in 2015. I've made over 2000 clocks for happy customers.