kungs: 315B; Miniloktals
The schematic notes the following tubes:
DK25 / DF25 / DBC25 (and DL21)
Comparing the pin allocation with data sources the different pin allocations are obvious.
DL21 is ok.
but there are discrepancies for
DK25: pin 5+6
DF25: pin 3+4
DBC25: pin 2+3
On the other hand the given allocations are matching exactly the related but not identical Mini-Loctals (we call them Miniloktals):
At Miniloktals the pins are positioned on a smaller circle of only 15 mm dia. (standard is 17.5 mm).
The center locking pin is also smaller than the standard one.