I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Jimmie

On Fri, 3 Apr 2009 07:34:16 -0700 (PDT), JIMMIE
wrote:

I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Jimmie

You might try reducing the current to the nixies by adding some series
resistance. Those 74141s are going to get hard to get. I made a
clock with nixies in the early 70's and it is still working fine.

W0BF

Yeah, a handful of MPSA42.

If you find a reliable source of 74141, I'm in for some too.

Cheers!

"JIMMIE" wrote in message
...
I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

The 7441 appears to be pin-for-pin compatible, but with a different decode
pattern (one element is always on). It sounds like you might first want to
check the nixie power supply voltage, not just using a voltmeter, but with a
scope to see if it has spikes which might be destroying your driver outputs.
This is much more likely if the counter is using leading zero suppression
and the failed drivers are in the group which often in the blanked state.

HTH,

-NM

JIMMIE wrote:
I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Jimmie
The chips are failing for one of two reasons, over voltage or over
current. Try reducing the supply voltage to the minimum that will light
the nixies. Also try heatsinking the 74141's. They do make clip on
heatsinks for dip packages, but you can just superglue scraps of
aluminum to the top of the chips.

On Apr 4, 9:58*am, ken scharf wrote:
JIMMIE wrote:
I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Jimmie

The chips are failing for one of two reasons, over voltage or over
current. *Try reducing the supply voltage to the minimum that will light
the nixies. *Also try heatsinking the 74141's. *They do make clip on
heatsinks for dip packages, but you can just superglue scraps of
aluminum to the top of the chips.

This has been a problem on two different Systron Donner counters I own
and one we used at work years ago. It was such a regular thing at work
we added sockets to facilitate replacing the chips. I have done
likewise to mine but only as the chips failed. There are still a
couple of origonal chips in it. Mycounters are model 6153. I have
never had a schematic or manual for them and
This makes maintaining them a little difficult but having two of them
helps allowing me to compare signals and swap boards to help isolate
problems. If anyone has a schematic I would greatly appreciate it.

Jimmie

On Apr 3, 10:34*am, JIMMIE wrote:
I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Domestic 74141's are hard to find these days but on E-bay the Russian
equivalent is very common.

Yes, you could build just about anything with a one-of-ten decoder and
some current-sink drivers to do the same.

If the goal isn't nixie tubes but is a working frequency counter, you
could probably put the counter up on E-bay for somebody who wants
nixie tubes, and use the money to buy several superior frequency
counters.

Tim N3QE

On Apr 8, 9:51*am, Tim Shoppa wrote:
On Apr 3, 10:34*am, JIMMIE wrote:

I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.

Domestic 74141's are hard to find these days but on E-bay the Russian
equivalent is very common.

Yes, you could build just about anything with a one-of-ten decoder and
some current-sink drivers to do the same.

If the goal isn't nixie tubes but is a working frequency counter, you
could probably put the counter up on E-bay for somebody who wants
nixie tubes, and use the money to buy several superior frequency
counters.

Tim N3QE

I forgot that the 74141 was also a decoder chip. I was thinking it was
just a driver. That complicates things a bit.
As far as the quality of the counter goes it works just fine and I
still have a few 74141s though my supply is getting low. I may try
some of the Russian chips.


JImmie

JIMMIE wrote:
On Apr 8, 9:51 am, Tim Shoppa wrote:
On Apr 3, 10:34 am, JIMMIE wrote:

I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.
Domestic 74141's are hard to find these days but on E-bay the Russian
equivalent is very common.

Yes, you could build just about anything with a one-of-ten decoder and
some current-sink drivers to do the same.

If the goal isn't nixie tubes but is a working frequency counter, you
could probably put the counter up on E-bay for somebody who wants
nixie tubes, and use the money to buy several superior frequency
counters.

Tim N3QE

I forgot that the 74141 was also a decoder chip. I was thinking it was
just a driver. That complicates things a bit.
As far as the quality of the counter goes it works just fine and I
still have a few 74141s though my supply is getting low. I may try
some of the Russian chips.


JImmie

As I noted in a previous email, the 74141 is still available, but
looking at Mouser, I see they are not exactly cheap...but...it beats
hacking up a piece of equipment and trying to use a completely different
part...here's the link to Mouser's part...

http://www.mouser.com/Search/Refine....yword=nte74141

Scott
N0EDV

JIMMIE wrote:
On Apr 8, 9:51 am, Tim Shoppa wrote:
On Apr 3, 10:34 am, JIMMIE wrote:

I have a Systron Donner frequency counter that uses Nixie tubes. The
counter works fine but I am forever replacing the Nixie drivers
74141s. I started to use it this AM an one was out. Is there a
replacement for the 74141, I couldnt find one, or is there a circuit I
could build on a DIP header to replace them. I could probably design
one but I wanted something tried an tested as I dont want to put my
counter board at more risk than I have to.
Domestic 74141's are hard to find these days but on E-bay the Russian
equivalent is very common.

Yes, you could build just about anything with a one-of-ten decoder and
some current-sink drivers to do the same.

If the goal isn't nixie tubes but is a working frequency counter, you
could probably put the counter up on E-bay for somebody who wants
nixie tubes, and use the money to buy several superior frequency
counters.

Tim N3QE

I forgot that the 74141 was also a decoder chip. I was thinking it was
just a driver. That complicates things a bit.
As far as the quality of the counter goes it works just fine and I
still have a few 74141s though my supply is getting low. I may try
some of the Russian chips.


JImmie


It appears they still make the 74141. Here's a list of suppliers
according to NTE...

http://dilp.netcomponents.com/cgi-bi...1&partnumber2=

Scott
N0EDV