Recently on the Facebook Nixie Clocks Fan Page, Peter asked if anyone had a design for a Z1000 tube mounting board. I did something for a friend who had a box of Z1000 tubes, and didn't have the possibility to design boards himself.
Here is the KiCad archive (design files and Gerbers, in the "CAM" directory):
ZM1000 6 digit display board, without separators
This clock was kindly supplied by Millclock for review, so many thanks to them for sending the clock to me. Previously we reviewed one of the simpler clocks produced by Millclock (the IN-12 Walnut clock) and this time we're looking at the other end of the range.
The Nixie Six is a six digit IN-14 clock with compact digits and a whole load of features. The version I have comes in a formed black acrylic case, with a sturdy transparent base plate, neon separators, and an external 12V power supply. The appearance is pleasing:
The power supply has a slightly smaller than usual jack, but is a standard DC jack, and has quite a short lead, but I'm sure that you can find a supply with a longer lead if you need it. For most purposes, the lead supplied will be adequate.
The unit has GPS time synchronisation, meaning that it keeps good time. The GPS antenna unit has a very long lead on it, meaning that you can easily and unobtrusively mount the antenna in the vicinity of a window, which is a pre-requisite for good time synchronisation.
Whereas the IN-12 clock gave the impression of being a pre-production unit, the Nixie Six is very definitely a mature production design. There are no rough corners or loose ends, and everything fits properly and clearly a lot of time has gone into making it a polished unit. Indeed, the clock version number, printed on the bottom of the PCB is v2.0.1, again with the slightly strangely motto "properly assembled in UKRAINE". I do understand why Millclock is trying to say with this motto, and I do know that I am being somewhat facetious, but in English it just sounds a bit strange. I wonder what the difference in assembly would be if it was "improperly assembled". Would that mean that it is assembled by children? Or by slaves? Or perhaps by adults, but with their trousers down? Or all three? I know that Millclock are trying to say "assembled in the UKRAINE with care and attention, using state of the art technology and tools, great quality control and an eye for detail", but somehow "PROPERLY ASSEMBLED IN UKRAINE" has a better right to it,
The pitch of the tubes is quite tight, with only about 1mm between adjacent tubes in the digit pairs. This gives the clock a very "upright" appearance, especially because of the relatively large base height. The mixture of the black acrylic and transparent acrylic base work well. One slight improvement that I would suggest to Millclock: It would be good to have some rubber feet on the bottom of the acrylic base: acrylic scratches easily and the beautiful finish will deteriorate quickly if it is left as a raw acrylic on any hard, rough surface.
The clock arrived very quickly and was well packed,with no damage to the unit at all, and with very little risk of being damaged, even given the fragile nature of the IN-14 tubes and the fairly large size of the assembled clock. The box it came in was a sturdy "Ukraine Post" official box, and priority postage was used. Note that the cost of the postage is in the price.
The first thing to say about the Nixie Six is that it works well, keeps time reliably, and is in no way "needy". I have been using it for a couple of months, and it has never put a foot wrong. It's totally silent in operation, and has been a "fit and forget" experience. The GPS unit means that it tells the right time and you won't need to fiddle or adjust the clock at all. Even changes to Daylight Savings Time (DST) are automatic if you are in Europe or the US, or in a country that follows either of these DST change standards.
The GPS time is backed up by a battery powered Real Time Clock (RTC), and so the clock can run even there is currently not any GPS signal available. As with all GPS devices, it can take a couple of minutes to sync the time the first time, because the inbuilt GPS receiver has to understand where it is, and which of the GPS satellites are in the sky above it.
If you don't have the GPS version, there is the possibility to fine adjust the RTC unit, in units of about 5 seconds per day. RTCs are usually very accurate, but even these can drift over time or under certain circumstances, and the adjust feature allows you to correct this.
The manual is much longer and more detailed than with the very simple IN-12 4 digit clock, covering five A4 pages, and the specifications and the usage of the clock are covered. The main "settings" are laid out in an easy to use table, and the clock has three buttons ("menu", "+" and "-"):
A feature that I do like, is that the neon colons flash can be set to one of seven different modes:
1 - slow flash: One second on, one second off
2 - fast flash: 0.5 second on, 0.5 second off
3 - fast burst flash: two rapid flashes at the beginning of each second
4 - medium burst flash: two medium flashes at the beginning of each second
5 - "ping pong right": both separators on, but the brightness switches between the left and right separator (right colon mostly bright)
6 - "ping pong left": both separators on, but the brightness switches between the left and right separator (left colon mostly bright)
7 - "ping pong alternate": As "ping pong" but the bias changes each second (alternating between left and right bias).
This clock won't give you "feature overload", the ones the clock offers will cover the vast majority of user wishes, and you won't have to get exasperated by wading through the manual to fine what you want. It is mostly very intuitive.
Millclock didn't know that I was going to tear the clock down, but I think it is worth having a look inside it to see what you are getting. In general, if you are scared to have your clock torn down, then don't send it in!
The case comes apart quite easily and non-destructively, meaning that it will be a fairly simple task to change the RTC battery if you need to in the future. The clock itself is a two board design, one board housing the driver, and the other board holding the tubes, the separators and the RGB back lights.
The internals are really clean and professional. The board is well laid out, logically divided and neat and tidy. The tubes are all perfectly aligned, and have been clearly inserted using a jig, or by someone with a good level of skill.
The clock uses an STM32F103C8 controller, which is a powerful ARM Cortex-M3 device with 64kB of flash and a maximum clock speed of 72MHz, but in the case of this clock, it is using it with a 32.768kHz external crystal for the inbuilt RTC and probably uses the internal RC oscillator running at 8MHz for the control circuitry. The RTC consumes just 1.5uA when the clock is off, so a standard CR1220 battery with a capacity of 36mAh will last about 24000 hours, or about 1000 days. However, the 32.768kHz crystal is not temperate compensated, and therefore the need for the RTC calibration. I would complain about this if the clock did not have the GPS antenna, but it does have GPS, and is unlikely to give you any problems in practical use.
The display is multiplexed using a K155ID1, and uses classic NPN-PNP discrete drivers for the anodes, using SOT-23 transistors marked 1D (NPN) and 2D (PNP), presumably the MMBTA92 which has a voltage rating of 300V, or the KST93.
The tubes are mounted close to the display board, with just enough clearance under them to allow the SMD 5050 RGB LEDs to be mounted. The RGB LEDs, which are divided into three sets of two RGB LEDs, one for each pair of digits, using NPN transistors marked 1GW, which is a general purpose SOT-23 NPN transistor.
Millclock are following a strategy which I think is the right for them to build a brand over the long term: Offer high quality items at the price which allows you to guarantee the quality. Millclock clocks are not cheap, but if you want to have a no-nonsense, "get-it-done" clock, you will not be disappointed if you buy Millclock.
Buyers of luxury items (and let's face it, Nixie clocks are luxury items: a $3 LED or LCD clock will tell the time just as well) forgive the price if the quality is there, but will not forgive failure and unreliability. From this point of view, I think Millclock are on the right path, and the Nixie Six is good choice.
Millclock offer a one year warranty, and will give you a 10% discount if you mention this article!
The beloved NumiQueen started to have problems the other day. One minute it was fine, and then the next minute the display faded and then only one digit came on, and dimly. I feared the worst, especially as I have become attached to the large bright display of the IV-13s.
I have other clocks in the same room (which Nixie fan doesn't have an excess of clocks?) but that wasn't the point. It's not about knowing the time: any fool can know the time, it's about knowing the time in style...
I turned the NumiQueen off and on. Many years of using Windows taught me that turning off and on solves most problems, but it didn't solve this one. I turned it off and left it off for an hour, to let any hot components cool off. That also didn't help much. The display would run correctly for a few seconds and then dim out again.
Clearly this was a sick clock. Jürgen from Nixiekits is in the middle of moving at the moment, and he's not online much to ask questions of, so this is a problem that will have to be solved by yours truly.
After doing some investigation, the problem appears to be with the power supply. Looking at the output with a scope, the smoothing is not at all smooth. Sniffing the case of the external power supply confirms the suspicion.
I opened the power supply case and this is what is in there:
The electrolytic capacitors for the output smoothing have indeed vented. One of them has a vaulted dome on top of it, and the other seems to have just splurged gunk over the board.
The inside of the upper part of the case is also telling. The nasty electrolyte is all over it, and it is very obvious that the capacitors are dead:
Extracting the capacitors makes the case totally clear. The power supply is only a couple of months old, but both of the capacitors have failed in the same way. One has bulged the top and the other has vented from the base. Normally this should only happen from older, or over-stressed components.
Or... Ones that are crap.
I have never heard of the manufacturer "CTC", but it seems significant that both of these capacitors failed in the same way at the same time and after only a few weeks of service. Possibly a bad batch of components. Possibly a bad manufaturer.
But the point remains: If you have a NumiQueen and you have problems with the power supply, it could well be this the cause.
Fixing it was easy: Solder in two new electrolytic capacitors of the same value, but with a lower coefficient of crapness, and we are on the road again, Now it just remains to be seen if there is a further problem in the design of the supply, or if it really was just some sub-standard components.
Is this (click on the image to see the full resolution picture of the madness):
I'll be testing myself against it in a fight to the death:
Who will win? (My money is on the clock).