P896B night vision tube

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fxchampion
Posts: 1
Joined: 19 Sep 2018, 14:43
Location: Sthlm

P896B night vision tube

Post by fxchampion » 19 Sep 2018, 20:38

Hello,
This is my first post to this forum and hopefully I have come to the right place.
I am planning to build myself a night vision setup and I have just recently bought a P896B tube (see image link).
However I can not find anywhere what kind of voltage I need to power this thing up, nor how to connect cables.
Any help would be much appreciated!
https://imgur.com/a/7xdHJmX

Cheers!

Lambda
Posts: 22
Joined: 31 Oct 2017, 17:41
Location: Den Haag, NL

Re: P896B night vision tube

Post by Lambda » 05 Oct 2018, 10:24

Hi.

Here is the datasheet of your tube (p. 675-677 of the pdf document):

http://www.anifur.com/ebay/eev.pdf

It seems that you need to feed the tube with an H.V. oscillator providing around 2.7 kV at 1.2 kHz.

Such hypothesis is based on reading the following citations coming from the description of this tube:

"The electrostatically focused modules are encapsulated in silicone rubber
together with an e.h.t. multiplier circuit to form a rugged, compact, lightweight
device
".

e.h.t. multiplier circuit is normally designed to be fed by an A.C power supply or oscillator, to deliver, after voltage multiplications and rectification, a D.C. High voltage.

and
"note 4":

"4. A very compact oscillator, with a suitable socket for the tube, can be
supplied
. This unit operates from a 6.75V d.c. supply; since the current
required is only a few milliamperes a mercury cell is suitable
."

See also the figure from the datasheet indicating an "oscillator input connector".

It seems that EEV was able to provide (on demand) this tube with an external oscillator configured to be fed with a simple DC power supply of 6.75V. The oscillator feeding in turn the e.h.t. multiplier of the tube. This would lead to a system similar to the P8079HP, concerning electrical supply requirement. The difference being that in the P8079HP, the oscillator is already build in.


So basically, if your tube is naked and corresponding to the description of the datasheet and illustrative photo, there is a big chance you need to:

- build an H.V. oscillator (2.7 kV at 1.2 kHz, modulo the tolerance indicated in the datasheet) able to deliver few dozen of mA, to be in peace and sure to be well dimensioned and "confortable". and to connect the output of this oscillator to the connecting pin of the tube ("ground" of the oscillator being connected to the "ground" of the tube (should correspond to the metallic ring surrounding the entrance fiber glass window.)

But perhaps, contacting EEV for asking? perhaps they have some archive and still available informations?

Hoping it will help you.

Good luck.

Lambda

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