Found: 15GP22 (I think)

[oldradio99]

First of all I am not a TV guy. I am a radio guy. I know enough to generally just get me in trouble.

Purchased some radio related items and found this. I knew enough that I knew portal tubes were generally collectible. But that was my limit.

After I got it home and started dusting and doing some research I discovered this may be a 15GP22 that was used in a RCA CT-100.

In speaking with the seller, this tube may never have been installed in a set. Her dad was always bringing home prototypes.

I know that good tubes are better than non working.

So how can I get this tested? And how do I verify that this is a rarer color portal tube and not just some black and white portal cheapie?

Thanks