Late production 4P1L tubes

[mcandmar]

Picked up these tubes recently and was surprise to see the date of manufacture was Nov 1986, i never knew they were manufactured so recently.  They also have very minimal getter material on the sides of the glass so you can actually see inside them, rather pretty little tubes when glowing away

1986 vintage http://www.ebay.co.uk/itm/182004110963

On the other end of the spectrum, the same seller has 1961 vintage tubes which have a very heavy coating of getter material the point almost all of the tube has a mirror finish.

1961 vintage http://www.ebay.co.uk/itm/182021807307

I thought they were interesting enough to be worth mentioning...