Need help with Nixie (NL-840 tube) clock design

[Phil Nelson]

So, we were out of state visiting relatives during Christmas week, then
returned home to find still more relatives camping out at our place. They
stayed for another week -- O joy :-(

When with drooping eyes we stumbled in from the airport to celebrate the
third (yes, third) Christmas gift opening, I found a handful of radio tube
boxes in my stocking, jumbled around with mints, chocolates, and whatnot.
"Cute -- garage sale crap," I thought, and put them aside.

Today I got around to looking at the handful and discovered six NIB National
NL-840 Nixie tubes, each including a base and matching IC chip.

I guess my brother-in-law's challenge is to make a Nixie clock. (He is an
actual "rocket scientist" -- a grey-haired guidance expert from Florida.)

Also in the stocking, and perhaps these are unrelated stuffers, 10 NIB
Miller coils: eight 3-10 mh (#9060), one 19khz (#1361) and one 38 khz
(#1362).

Anyway, the draggers are drawn. I need an NL-840-based Nixie clock plan, and
I need it now!

The ICs included with the Nixie tubes have the following markings:

DM/SN7441AN
NS8840N 122

Regards,

Phil "doesn't do solid state" Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
To send me email, kindly visit http://antiqueradio.org/contact.htm

 

[Eric Sears]

So, we were out of state visiting relatives during Christmas week, then
returned home to find still more relatives camping out at our place. They
stayed for another week -- O joy :-(

When with drooping eyes we stumbled in from the airport to celebrate the
third (yes, third) Christmas gift opening, I found a handful of radio tube
boxes in my stocking, jumbled around with mints, chocolates, and whatnot.
"Cute -- garage sale crap," I thought, and put them aside.

Today I got around to looking at the handful and discovered six NIB National
NL-840 Nixie tubes, each including a base and matching IC chip.

I guess my brother-in-law's challenge is to make a Nixie clock. (He is an
actual "rocket scientist" -- a grey-haired guidance expert from Florida.)

Also in the stocking, and perhaps these are unrelated stuffers, 10 NIB
Miller coils: eight 3-10 mh (#9060), one 19khz (#1361) and one 38 khz
(#1362).

Anyway, the draggers are drawn. I need an NL-840-based Nixie clock plan, and
I need it now!

The ICs included with the Nixie tubes have the following markings:

DM/SN7441AN
NS8840N 122

Regards,

Phil "doesn't do solid state" Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
To send me email, kindly visit http://antiqueradio.org/contact.htm

Hi Phil
I liked your story about the stocking stuffers! I just get old defunct
cordless telephones etc from my rellies - I got a whole bunch together
with a Motorola bagphone from my sister this year!!

Anyway, I also inherited a bunch of Nixie tubes - I think the same one
you have, together with the same I/C's (I recognise the SN7441) some
years ago. These were together with some pc boards (about 1x1.5inch),
and I THINK some sort of circuit for a frequency counter (not a
clock). I believe the circuit was in about a 1960's or 1970's
"Break-In" magazine (the mag of the NZART).
Unfortunately, as I have just shifted house, finding it in a hurry it
not feasible! But I will have a look around some time - hopefully I
didn't dispose of them when I moved. I also have copies of the mags
back to about 1960, so if I find time I will have a look.

Best wishes

Eric Sears ZL2BMI.