Cathode Corner NWLD User manual

NWLD Nixie Watch
User Manual

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Copyright (C) 2021 Cathode Corner. All rights reserved.
Printed in USA
Watch made in USA

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Table of Contents
Introduction........................................................................................ 5
Warranty ............................................................................................ 7
Operating Instructions ........................................................................ 9
Maintenance ..................................................................................... 12

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Introduction
The Cathode Corner Square Nixie Watch is just about the most unusual
yet practical timepiece you can wear on your wrist. It is a two-digit
Nixie tube wristwatch designed for everyday use. It’s guaranteed to get
attention. People will ask you, “What is that? Is it a watch? Show me
how it works.”
The Nixie Watch is water-resistant and rugged. The battery is easily
charged via the Micro USB port on the side. The watch requires no
button pushing to operate – it shows the hours, minutes and seconds in
sequence at the flick of the wrist. It provides a bit of theater with every
reading.
The large crystal shows off the workings of the watch: the tubes, battery,
and high-voltage power supply are all visible.
The watch features 12 or 24-hour time display mode, user-settable tilt
angle, and easy time setting operation. The timekeeping rate is
adjustable and the watch comes pre-adjusted to within a second a week.
The two Nixie tubes are the widely available B-5870 type and are
socketed for easy replacement in case of damage. These tubes have 0.6”
(14mm) tall digits for easy reading in adverse conditions.
The case is made of strong, lightweight aircraft aluminum. The rear half
is hard anodized for long life on your wrist. The front of the case is
gently contoured for comfort in all-day use, and is available in a variety
of colors. O-ring seals keep out water, dust and dirt. The strap is a
standard 22mm size, so a replacement strap is available at any fine
jeweler.

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Specifications
Size: 48mm wide 53mm tall by 16mm thick
(1.9” wide 2.1” tall by 0.63” thick)
Weight: 2 oz. (60g) exclusive of strap
Crystal window: 32.5mm x 27.4mm x 1mm thick mineral glass
Strap width: 22mm between lugs
Battery life: Approximately 2-4 weeks at 50 viewings per day
Charging time: 3 hours at 5V USB, 80 mA max.
Replaceable Parts
Battery: 631235 size Li-poly (rechargeable), 3.7 Volt, 200mA-hour
Case O-Ring: 40 to 42mm ID x 0.70mm
Button O-rings: 2.2mm ID x 0.50mm
Screws: Four 0-80 x 3/16” stainless steel socket head cap screws
Nixie tubes: Two B-5870 or equivalent, 0.6” (14mm) tall digit side-view

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Warranty
Thank you for your purchase.
The Nixie Watch is guaranteed for a period of one year after date of
purchase to be free of defects in materials and workmanship. In case of
malfunction, the watch will be repaired or replaced at the discretion of
Cathode Corner. The customer must send the watch at their expense to
the address given below on this page (or as listed on the website
mentioned below). This warranty does not cover the cost of shipping the
watch to Cathode Corner for evaluation. It does cover the return postage
to the customer.
The software programmed into the microprocessor in the watch is
licensed under the General Public License and carries NO WARRANTY
WHATSOEVER, including merchantability and fitness for a particular
purpose. See the source code files on the www.cathodecorner.com
website for more information.

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Contacting Cathode Corner
Cathode Corner wants to have only satisfied customers. If you are
having trouble with your watch or you just want to talk with us about
fun things, you may contact Cathode Corner in any of the following
ways.
Visit Cathode Corner on the Web at www.cathodecorner.com
Phone: [phone]
Email: [e-mail]
Mailing address:
Cathode Corner
260 E Ross Pl.
Tucson AZ 85716
USA

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Operating Instructions
Charging the Battery
The watch is shipped with a charged battery. When the battery runs
down to about 20% remaining charge, the watch will indicate this by
causing the display of the minutes to flicker. This is a warning that you
should charge the watch in the next day or so.
Charge the battery by connecting the watch to any USB charger or
computer via a micro-USB cable. These cables are so common that you
probably already have several. Charging time is under three hours. The
watch has a built-in charge controller that automatically shuts off when
the battery is full, preventing overcharging.
If the battery is allowed to run down fully, the watch will stop
displaying the time altogether, although it will enter time-setting mode.
There is an undervoltage protection circuit built into the battery to
prevent a dangerous complete discharge. Nonetheless, the battery
lifetime will be reduced if left discharged for several months.
Setting the time
You may set the time on the Nixie watch by pushing the two buttons on
the right side in the proper sequence. The lower button is the Set button.
It selects the time-setting mode. The upper button is the Adv button. It
advances that portion of the time that is selected for setting. If you push
the Adv button first, nothing will happen.
The Set button cycles through a sequence as follows:
Normal display mode
12/24 hour select (displays ‘12’ or ‘24’)
Hour setting (both digits flash)

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Tens of minutes setting (left digit flashes)
Units of minutes setting (right digit flashes)
Seconds reset (counting seconds shown)
Tilt angle (displays ‘45’)
Normal display mode
Go ahead and press the lower Set button seven times to observe the
modes listed above. When you have finished the cycling through the
setting modes, the display will be blank again.
To begin setting the time, press the Set button once. The display will
show 12. Pressing the Adv button causes this number to alternate
between 12 and 24. When 24 is selected, the watch is in 24 hour display
mode and the hours will range from 00 to 23. When 12 is selected (the
default), then the watch is in 12 hour mode and the hours will range
from 01 to 12.
Press Set to enter hour setting mode. The watch displays a blinking 01.
This is the hours. To increment the hours, press the Adv button
repeatedly until the proper hour is displayed.
Press Set to set the tens of minutes. The watch displays the current
minutes with the left digit blinking. Press Adv repeatedly to set the left
digit of the minutes properly.
Press Set to set the units of minutes. The watch displays the current
minutes with the right digit blinking. Press Adv repeatedly to set the
right digit of the minutes properly. It’s a good idea to set it one minute
ahead so that the seconds reset that follows will leave the watch set to
the correct minute.

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Press Set to enter the seconds reset mode. If you like, you may reset the
seconds to 00 when your reference clock reaches the top of the minute.
However, the setting mode automatically turns itself off after 30 seconds
have elapsed without any button pushes, so press Adv every few
seconds to stay in time-setting mode.
Press Set to enter the tilt angle setting mode. The watch will display 45,
which is a hint of the angle (in degrees) to hold the watch at when
setting the tilt angle. Hold the watch at a comfortable viewing angle with
the tubes facing up and toward your face, and press the Adv button. The
display will blink once as the tilt sensor is read and its angle stored for
reference.
Press Set again to exit time setting mode. The display will be blank.
Hold the watch steady at the tilt angle you set it to, and the display
should flash the hours and minutes. If you have difficulty getting it to
display the time, try setting the tilt angle again at a slightly different
angle.
Using the watch
The Nixie watch is simple to use. Once it is set, it will activate the
display when tilted to the desired viewing angle. The hours are
displayed first, then the minutes, then finally an incrementing seconds
display if held at the viewing angle.
It may take some practice to get the watch to display the time every time
you tilt it to viewing angle. In the current version of the software, the tilt
angle sensitivity is variable depending on exactly what angle the watch
is set to. So if it’s not sensitive enough, try setting the tilt angle again.
That will usually clear up the problem.
After a while, your arm will seek the correct angle automatically.

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The seconds display is designed to indicate the passing seconds while
minimizing the power used. The seconds will only show up as long as
the watch is held at the proper viewing angle. Also, the duty cycle of the
display diminishes to zero over a period of twenty seconds. You will
notice that the time that each number is displayed grows shorter, until
the display is flashing each passing second very briefly. In spite of this,
it is easy to read the displayed number since you know what it will be.
Maintenance
Changing the battery
The battery is expected to last for several years. If it fails to hold a
charge, it will require replacement. Contact Cathode Corner as shown on
page 8 for a replacement battery.
Water resistance
The Nixie watch is designed to be water resistant, but it is not sealed
against pressure. It should withstand rainfall, splashes and other
everyday liquid events. However, the seal is not necessarily sufficient to
protect the watch against submersion in water. If it should be
submerged, remove it from water right away, remove the cover with the
four .050” (1.3mm) hex head screws on the rear, and check for water
ingress. If the insides have gotten wet, first remove the battery, then
shake out any loose water and dry the watch by placing it in a warm, dry
area with the cover off.
If the inside of the watch has been soaked in water, it is best to remove
the module using a 0.050” (1.3mm) hex key, then thoroughly dry the
module and the inside of the case by blowing it dry with compressed air.

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Replacing the Nixie tubes
The Nixie tubes are somewhat delicate and may crack or develop shorts
between two adjacent cathodes after a drop or a hard bump. The only
known cure is to replace the bad tube. Replacement tubes are available
from Cathode Corner at nominal cost.
It is wise to have Cathode Corner replace the tube(s) for you unless you
are a skilled technician with access to a stereo microscope. If you still
wish to do it yourself, then please take the time to read all the
instructions below. This may change your mind.
If you would like Cathode Corner to do the work, send the watch and
appropriate payment to the address on page 8. You may also elect to
have a watch repair shop do the work, but they are not likely to have any
more experience at it than you do. They should have the necessary
magnification eyewear, however, and they might be amused to see such
an unusual watch.
To replace a tube, it is necessary to remove the module from the case as
described below.
Remove the cover by removing the four screws on the rear, using a
.050" (1.3mm) hex key.
Unscrew the two socket head screws near the USB connector, using a
.050" (1.3mm) hex key.
Put the screws in a safe place such as inside the case cover.
The module is held in place by double-sided tape under the left side. The
tubes are held in place by double-sided foam tape. To free the module
from the case back, pull up gently on the battery and the circuit board at
the base of the tubes.

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Lift the module out by prying up on the left side of the circuit board with
a tiny flat screwdriver to release the double-side tape that holds it down.
Don’t worry, there are no circuit traces below that part of the board.
The old tubes may be removed by simply pulling its nipple end up to
clear the transformer, then pulling it out of the socket. The tube is held
in place with a small pad of double-sticky foam tape. This tape must be
cut away to remove the tube. The foam pad is a piece of 3M foam
mounting tape.
Peel off the old foam pad slowly to prevent tearing. Clean off the old
adhesive with your fingernail.
Remove the covering from one side of a new foam pad and press it into
place where the old one was, in about the center of the space left by the
tube. Leave the top cover sheet on the foam pad intact. It will be
removed after the tube is plugged into the socket.
Installing the new tube can requires patience and a steady hand. It is
done most easily under a microscope, but any magnifying lens is
helpful. It is best to use a self-supported magnifier since both hands are
needed to install the tube. A pair of fine point tweezers or a fine-tipped
prod tool is also very helpful to coax the tube pins into the socket.
The tube pins are made of thin wire and are flexible. This is good in that
it’s easy to align them, but bad because they need to be aligned. The
tube comes with a plastic spacer that keeps the pins aligned moderately
well.
First, the tube pins should be prepared. Inspect them and bend the pins
so that they point straight out from the plastic spacer. Check that the
rows of pins are straight. Then pull the spacer off the tube and set it
aside.

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The two pairs of pins nearest the back of the tube often have trouble
entering the socket unless they are bent just a little bit towards the other
pins. So do that. A distance of .020” (0.5 mm) is sufficient.
Now hold the module in one hand while holding the tube in the other
hand, and guide the tube into place. The front pins will engage first,
followed by the rear pins. The tube may just slide into place, or one or
more pins may get hung up on the socket. This happens because the pin
ends are cut square and the sockets have an insert with a little shelf for
the pin to get stuck on.
This is where the tweezers or prod come into play. Push gently on the
stuck pin in the proper direction to center it in the socket, and it should
pop into place. If that doesn’t work, then try removing the tube and
bending the affected pin the proper way to allow it to fit on the next try.
It may take a few tries, but it will eventually go in. Only the factory
workers are able to get all the pins in on the first try.
Check to be sure that all twelve pins went into their sockets. One might
have bent rather than going in. If so, remove the tube, bend the errant
pin into place and try again. It will be easier next time.
After the tubes are installed, the foam pads need to be installed. Do this
by using the tweezers or prod to remove the top covering from the pad,
then making sure the tube is aligned with the other tube and pressing it
down into place on the foam pad.
After the tube(s) have been replaced, the module may be reinstalled in
the case. Drop the module into the case and align the two screw holes in
the module with the holes in the case. Place a screw on the hex key tip
and guide it into position in one of the screw holes. Screw it down
nearly all the way. Install the other screw using the same method, then
tighten both of them finger-tight with the hex driver.

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Install the battery and replace the cover, then set the time. Check that the
tubes are displaying all digits (0-5 for the left tube, 0-9 for the right
tube) properly.
Cathode Corner
2560 E Ross Pl.
Tucson AZ 85716
USA
www.cathodecorner.com