Pre-war CRT in Dr Röntgen's rays

[LENINGRAD T2]

Today's commercially available vacuum pumps allow you to obtain a vacuum at least three levels deeper. The ion pump can be connected for several days. I am optimistic that this will eliminate the need to heat the picture tube and use an induction heater. Of course, this requires testing and then observing the picture tube over time. As I mentioned earlier, I have over 100 new guns with a cathode without activation. They come from the 1970s. I do not know the current condition of the cathodes. This also requires investigation. Shortly before the pandemic, I rebuilt several picture tubes in Russia. At that time, it was probably the last operating workshop of this type in the world. The new electron guns undoubtedly came from the 1960s and 1970s and were probably not stored in special conditions. The cathodes therefore lasted a long time. I checked all the picture tubes and showed good emission. For geopolitical reasons, contact with the workshop was interrupted.

[LENINGRAD T2]

Can a pure nitrogen atmosphere be used for the work, with expert breathing via airlines?

There are special chambers for working with inert gases. Unfortunately, their dimensions are usually small for laboratory needs. A CRT, especially a pre-war one, will not fit easily.

[LENINGRAD T2]

The cathode is activated in a vacuum and is spoiled immediately as it's exposed to air.

Personally, I have high hopes for using H/C sets from a working CRT. During such work, the activated cathode will of course be exposed to contact with air. There is no clear data on how much time (seconds? minutes? hours?) is needed for irreversible destruction of the cathode and significant loss of its emission. At least I have not found such studies. Certainly, a very dry environment will slow down this process - slower hydration. In the glory days of electron tubes, such phenomena were not thoroughly studied, I think, because they had no practical use. Rebuilding the CRT consisted of installing a new gun taken from the shelf, not transferring it from another. The first experience with the CRT that I have planned will be the elimination of the vacuum and its quick restoration without manipulating the electron gun. Emission control after such a test will be interesting.