MOTM

>a) who said *I* was soldering it? :)
>
>b) for all the folks that wanted Nixies and gas tubes (in German, just
<scroll and look at photos):
>
>http://www.jogis-roehrenbude.de:80/Leserbriefe/Bruegmann-Digital-Roehren-Cl
ock/Digital-Roehrenuhr.htm
>
>Paul S.


a) I see, you'll just command your hoards of solder slave minions to descend
upon it? ;-) 

b) wow, that looks like even more work! Some reasonable translation efforts
can be done at http://babelfish.yahoo.com/ Here's a sample:


Digital Nixieröhrenuhr
of Friedhelm Bruegmann

To the readers:
Some readers will already already know my project. For well one year one
could pursue here the building progress. I have myself to revise and try
completely again united with Joachim on it, after the equipment was now
finished, my presentation, you readers the technical details and perhaps
also the emotional reasons, which let this project develop, a little obtain.
In a Posting in the forum the question was to read “what induces one to
building such equipment? To answer not easily, this question. Surely it is
the glowing passion, which pursues me since my childhood. At that time I was
fascinated of the fact that one could operate a EF80 with approximately
15-20 V of filament voltage like a lamp and all filigranen details in the
sharp red light appeared. That took so 10 minutes, then was she. Which sin,
these many EF80, which I brought at that time “over Jordan”. The cellar of
my parents filled watching with television and radio chassis of the check
garbage. An almost inexhaustible source of these so beautifully glowing
“lamps”.
There it gave also different “lamps”, those was me too largely, there could
one not clean-look, like that something like AL4, AF7, ECL11 etc. Those were
then placed on the pavement and shot with the Zwille drauf. I spider, that
was not like that. Fast however the pure tube collecting passion developed.
I built the first tube amplifier with 19 years. There I went still to the
teachings and to the teachers with my questions on the spirit went. This
Stereoverstärker with 2x EL34 in Gegentakt Ulralinearschaltung was
completely revised of me before a few years and is today still my stereo
system.
The tube collecting passion continued until today. There some accumulated
already in such a way. Now did the question, which you make with these many
tubes, arise to me? Thus me the idea came to build with tubes somewhat
completely strange and perhaps also unique what at all no commercial value
has, actually only stood and one cannot operate it permanently, because the
electricity bill becomes otherwise too high.


!! A DIGITAL CLOCK!!



The concept
upward
The original concept
When the idea was born 1998, I had to make thoughts over it, as begin myself
I best. The difficulty for me consisted now of converting a standard TTL
Uhrenschaltung in tube technology. Thus I looked after suitable literature
again and collected myself all information necessary for me together. I made
myself a small mother board also to a few tube versions and began to
experiment.


Did not stand firmly for me from the outset, it should semiconductors in the
equipment to find be and it should also no “tube IC's” give. I mean with it
the counting tubes like for example the well-known E1T. Also cold-cathode
tubes, which found use in former times gladly in ring counters (organs,
etc.), were not intended. The counting stages should be developed only with
completely classical flip-flop stages. The 1-second pulse should be won most
simply from the frequency and be responsible for the current supply a tube
power pack. For indicator decoding relays were intended at the beginning. I
regarded and on the necessary number of tubes analyzed each functional
module separately. From these first considerations I designed then the
chassis. The following picture however already shows it with an extension at
the left and right side. Whereupon I later still return.

If we exclude ourselves these extensions times, we see the regular power
pack for the operating voltages under the left transformer. The necessary
tensions result from the circuit concept. The tensions +170V, +75V, -100V
and an unsettled tension are needed of 250V. 170V is übrigends a typical
operating voltage for tube digital technique. In the center eight divider
stages are to be recognized, whereby from right seen only the first three
divider stages are equipped.
Beginning from right first the two decade scalers, which produce the
1-second pulse, follow then the units position for the seconds display.
Later the further stages were then taken in enterprise. Under the right
Trafo 100Hz-Generierung with low-pass and Schmittrigger is arranged. That
was the original concept. The following two pictures show the wiring
suitably to the upper picture from the year 2002.



The entgültige concept
Fast noticed I, which represented the decoding of the counting stages for me
into a decimal announcement the largest problem and I had to reject the
original idea to use relays. Also experiments to want to replace the relays
by opto couplers failed fast because of the characteristics of the tube
technology. Also a classical project should remain finally. Thus nothing
else remained for me to likewise make decoding with tubes. I experimented
again with different circuit concepts, which I gained. A goal was at the
same time also a minimization of the necessary tubes.
At the end I developed a concept, which an extension of the chassis on the
right as well as left side made necessary. Left I had to extend the chassis
around 11 tubes and right around 12 tubes.
Now, the entgültige concept planned still another small change. Left I had
to likewise still bore the 12te hole and for two further tubes on still free
spaces was accommodated, so that I needed 26 double triodes for decoding
altogether of the type 5963.
The following picture shows the entgültige chassis. Among other things the
boreholes not equipped yet are to be seen, those still come of the first
concept. A few few holes to remain unbestückt, which I will then lock with
laminated paper plates. Down übrigends the six holes are to be seen, which
were intended ursrünglich times for the digital indicating tubes ZM1040.
There I will install a small built base, on which then these tubes place
find, in order to be able to emphasize her somewhat.