Sockets vs PCB-mounted socket pins

[gregebert]

Has anyone had problems, notably cracking around nixie tube pins, using socket-pins soldered to a PCB, rather than using an actual tube socket ?

I'm doing my pcb design right now, and I'm hoping that I can avoid pin-stress if I put the socket pins on the tube, then solder in-place. I will not be physically switching tubes between sockets, though I may occasionally insert/remove a few times during final assembly.

Actual sockets might be an option, but space is pretty tight.

This clock has fourteen IN-18 tubes, so I want to protect my investment.

[David Forbes]

Stress on the pins is a result of the pins not fitting properly into the
sockets. It has been known to break the glass seal around the pins. Real
tube sockets have floating pins to solve this problem. That's one reason
that they are so tall.

Some people have used connector pin inserts such as the ones used on D
serial connectors. The height of the contact allows it to flex a bit
when installing the tube. However, this is not any shorter than a tube
socket.

Others have used oversized machined-pin socket pins, which have enough
room inside to accommodate some misalignment of the tube pin. The
contacts tend to have a wide diameter acceptance range, so this trick is
feasible. There are hundreds of different socket pins available from
Mill-Max via Digikey and Mouser. They are pricey, but so are IN-18 tubes.

Whatever pins you choose, make sure that the pins are straight when you
install the tubes.

--
David Forbes, Tucson AZ

[Dekatron42]

If you use the pins sold on Ebay which have a wider middle piece to secure them inside DSUB contacts you can also do a sandwich design with at least three pieces of PCB on top of each other where the middle layer has a somewhat bigger hole to accommodate the wider piece and the top and bottom pieces have smaller holes so that the pins doesn't fall out. You can the solder flexible wires to the pins underneath and easily push the Nicie down onto the pins with as little stress as on other sockets. If you use sockets you should solder flexible wires to keep the flexing of the pins, using to hard wires will not let them flex enough.

I've use the sandwich design successfully on 26 & 27 pin Trochotron / Dekatron sockets, it takes some time to solder the wires to the pins but you get flexible pins that work like a charm. I also made a design where I used more PCB layers on top so the the upper part of the pin was hidden completely so that it was easier to push down the Trochotrons (BX-1000 & BX2004) onto the pins, this also protects the pins from bending to much when the tube is pressed down on top of the pins.

I tried to attach photos but it didn't work right now for some reason.

/Martin

[gregebert]

The pins I bought on Ebay have 3 distinct regions:

• There's the contact area that slips over the tube's pin, and it's springy enough to require several grams of force to remove (I'm unable to measure it, but it seems adequate). I intend to see how many pins are needed to support the weight of the tube, so that will give me an idea of the retention force.
• Midsection, about 1.6mm diameter. I was planning to solder this into the PCB. I just need to be very careful no solder wicks into the region that contacts the tube-pin.
• Tail-end, approximately 0.5mm diameter. I was planning to snip this off after soldering.

I've thought about having a friend 3D-print a shell to hold the pins, but it's probably overkill. Everything below the tube base, including the PCB, will be hidden inside the case.

Fortunately this clock will sit on a shelf, and never moved, so it's not necessary for the nixies to be tightly gripped. 

[Tidak Ada]

Hi Martin,

 

Great news!
Can you send me a PM with the photo's? My provider allows at least 10MB for attachments, but less as 15MB.

I am already looking long to make sockets for my EZ10A dekatrons with self adjustable bushings.

Please also ad an eBay number for these pins.

 

Thanks,

 

eric

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42
Sent: vrijdag 26 juni 2015 23:11
To: neoni...@googlegroups.com
Subject: [neonixie-l] Re: Sockets vs PCB-mounted socket pins

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[Tidak Ada]

Soldering the contacts directely in the PCB makes a quite stressfull connection for tubes with a high number of pins, because of designe tolerances. Therefore tube sockets for tubes with glass sealed pin feed-throughs alsways have loosly mounted socket contacts.

That's just what Dekatron42 describes.

 

eric

 

 

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of gregebert
Sent: vrijdag 26 juni 2015 23:41

To: neoni...@googlegroups.com
Subject: [neonixie-l] Re: Sockets vs PCB-mounted socket pins

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[Dekatron42]

I hope these photos work as an attachment now.

/Martin

[Tidak Ada]

Do you have a photo of a single contact? I need contacts for 0.9 - 1.0 mm Ø Do yours meet these specs?

 

eric

---

From: neoni...@googlegroups.com [mailto:neoni...@googlegroups.com] On Behalf Of Dekatron42
Sent: zaterdag 27 juni 2015 0:30

To: neoni...@googlegroups.com
Subject: [neonixie-l] Re: Sockets vs PCB-mounted socket pins

I hope these photos work as an attachment now.

/Martin

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[JohnK]

They look beautiful - I bet you 'feel good' when treating your Trochos so well !   I usually resort to pushing "blue links" onto tube pins when experimenting. [Blue links - common name for those rolls of wire with a sleeved connector pin crimped on every few inches. I first ran across them jumpering backplanes of DG computers.]

 

John Kaesehagen

Australia

----- Original Message -----

From: Dekatron42

To: neoni...@googlegroups.com

Sent: Saturday, June 27, 2015 7:59 AM

Subject: [neonixie-l] Re: Sockets vs PCB-mounted socket pins

I hope these photos work as an attachment now.

/Martin

--

[Dekatron42]

I'm not sure what size my pins are as I bought them from different sellers on Ebay and none had any specification that agreed with the pins they delivered, it varied a lot!

So if you buy a bunch of pins you'll have to make the PCBs fit for just those pins, but that is an easy thing to do in the PCB program.

/Martin

[Dekatron42]

Yes, it feels good to push down the 26 pin Trochotrons on those sockets, but the force needed is quite a lot, but not more than new original sockets. Soldering all of the wires however is a different story as it takes a lot of time (just as with original sockets).

I've tried those female jumper cables popular for Arduino projects, where a female contact is crimped onto the end of a cable and a male (or female) contact is crimped on the other end, but the quality is quite poor on those, I've had several contacts fall off without even pulling on them. So before I would use those I would check each and every cable pulling on the contacts. What you don't get with those is a proper socket that you can screw onto something, you just get a lot of loose wires and a loose tube. Unfortunately the contact part is too high up into the plastic sleeve that you can't use them on the other side of a single PCB as the pins are very short on the Trochotrons (Dekatrons like the Z572S have longer pins, but the GSA10G has too short pins).

One thing most sellers of the "Nixie pins" I used for the socket didn't say is that the thin pin which you can solder onto a PCB is not centered on the cheaper ones, it is slightly off to the side so you'll have to turn all pins in the holes to get the correct diameter, or bend each pin slightly so that the pin gets centered. The wider part of the pin just below the widest part is centered on all that I bought.

/Martin

[coggs]

I use  these socket pins
 https://octopart.com/1-5380758-1-te+connectivity-39734153

For my B7971x4 board <shameless plug>
http://www.cogwheelcircuitworks.com/zc/index.php?main_page=product_info&cPath=1&products_id=11&zenid=justp84h5skidnn21o3foojcm4

Initial insertion needs to be done with care, but I've yet to lose a B7971 during insertion.
..c