GM Tubes - Sov Tube Purchase

As I'm not familiar with forums, this forum, or where everything goes, this may be off topic here, but here goes.
The SBT-11A puzzles me. It has 4 segments, yet there are only 3 anode pins. With 2 ground pins, it should only need 2 anode pins to give connection combinations. Or, so it seems.
Not to put too fine a point on the resistive distribution, shorting the 3 anode pins and using 1 resistor should give the same balance of current to all segments; but I'm no electrical engineer... grin.

You mentioned getting duds. Have you ever ruptured the mica window and traced the internal segments and their connection pins?
Thanks for the replies and purchase link.

I have poked around inside a broken one, and I have a circuit diagram. There are four segments which could also be considered four GM tubes.
There are indeed only three positive connection pins - the outer two pins belong to the outer two segments and the inner pin is connected to the inner two segments.
The two negative connection pins are...joined together inside.
It's all a little odd really.

The specs give a current range of 0.3 to 1.5 uA per segment so, when open to a strong radioactive source, all the segments are firing like crazy, you may end up with a voltage drop ( and a drop in counts) due to a lack of current if you use only one resistor. You could use only one resistor of a lesser resistance to overcome this, but then there is a risk of damaging the tube at low counts....
...and maybe it's just like splitting hairs

Thanks for that clear description of the insides of an SBT-11A.
Also, thanks for giving the current rating.
I see the point regarding the resistors. Perhaps I'll find time to experiment with one later.
Still waiting for my ham tech buddy to cut a rectangular hole in the ABS box so I can wire up a little probe for my GK+4.

I have an aluminium minibox designed to house an LND7317, but I'm considering mounting two SBT-11A's in the space over the round hole and SS mesh. A cheaper alternative. Last time I bought an LND7313-3 pre-paid, including UPS delivery, it cost me $240. Canadian for a $150 tube. Then, UPS stiffed me for an additional $62. brokeridge fees and taxes. The SBT-11 is a much less expensive alternative.

Say, don't you split hares before cooking them? Grin.