20 May
2003
20 May
'03
12:29 p.m.
Hello,
Probably my best find at the recent Hamvention in Dayton OH was a
stack of nixie tube modules made by HP. In retrospect, I wish that
I had purchased the whole box of them, but I hopefully have enough
to at least make a clock.
I have two variations on the modules, the part numbers are:
HP 05212-6016 series 648
HP 05212-6003 series 415
I have a schematic for the 5212L-4A Series 401 counter which might be
closely related
They both use Borroughs B422 nixie tubes and look like
they may have
an integrated HV supply of some sort.
No. The black plasic block is a latch and decimal decoder (!). It
contains 8 neons (look like NE2s, but the parts list doesn't give
individual parts for this block) which perform the latching function for
the 4 bits and their inverses. The top of the block is a thick film
circuit of LDRs which forms a decoder tree to turn on the apporpriate
cathode of the nixie tube.
I can provide a pinout of the 15 pin card edge, but the signals may not
be too obvious without the complete service manual. Pin 1 is towards the
front (nixie tube) end
1 : -130V
2 :
3 :
4 : +170V
5 : Transfer Input (latch enable)
6 : BCD Output A
7 : Signal Input
8 : Gate Input (Not used?)
9 : BCD Output B
10 : Signal Output to next decade
11 : +20V
12 : Reset Input
13 : BCD Output C
14 : BCD Output D
15 : -15V
I would appreciate if anyone can tell me what HP (or
other) instruments
may have used these modules. I would also like to find a schematic of
Well, the 5245 Counter uses closely related modules (I have one of these
instruments and the full service manual...) Doubtless other instruments
did too...
-tony