![](https://i0.wp.com/scenario.org/wp-content/uploads/2023/03/B4BAF505-C72A-48BD-86EF-0CB67B8A8662.jpeg?resize=359%2C478&ssl=1)
Here’s the first tube. The glass is a perfect fit! I only had green fishing line on hand but this is proof that a more detailed internal structure will glow and breathe. Shown here powered at 4V. The size is 7mm diameter and 32mm long.
![](https://i0.wp.com/scenario.org/wp-content/uploads/2023/03/528E2833-B447-411B-8664-0F16179C6840.jpeg?resize=474%2C632&ssl=1)
Here is it powered at 12V. I will install eight of these inside Ronaldo’s two HIWATT amplifier heads.
![](https://i0.wp.com/scenario.org/wp-content/uploads/2023/03/4B668952-5F7D-4216-9276-F488D8941357.jpeg?resize=474%2C267&ssl=1)
Here are the unpowered placeholder bulbs Ronaldo is using.