Fixing old Nixie Clock (3)
Capacitor replaced
The replacement of the power supply capacitor with a new one cleaned up the pulses nicely.
The clock is running properly again for about two days now.… Read the rest
Category: Electronics
Fixing old Nixie Clock (2)
Remember that old Nixie Clock? For a while it ran properly, but now it skips time again at random intervals. So I got that big capacitor out that I suspected right away, because it has been in there for over 40 years. And unlike me, these things do not age… Read the rest
Fixing old Nixie Clock (1)
Father’s clock
My father built a Nixie clock in ‘ye olden days‘, over forty years ago… It was a relatively simple design compared to what we build nowadays.
Design and simplified workings
The clock derives it’s clock-pulses from the mains power, 50 Hz here in the Netherlands
Dividing it by… Read the rest
Experimenting transistor amplifiers (3)
The circuit for today
Today I take it up a notch, by making a two transistor amplifier. This time I use the circuit diagram at the right (published on Jos Verstraten’s website).
As a convenient touch, measuring points are given in the diagram, indicating the expected Voltages.
Building the circuit… Read the rest
Experimenting transistor amplifiers (2)
Follow-up
As a short follow-up for the previous post I will show you what is the result of using the right value for R4 in the schematic, which I did wrong in the previous post. I accidentally used a 47k resistor in the collector line of the transistor where it… Read the rest
Experimenting transistor amplifiers (1)
Today I thought I’d play around and build a simple amplifier, just for fun. I started out searching for circuit diagrams for “one transistor amplifier BC337“, just because I have a couple of those BC337’s laying around. I found a schematic that you can see to the right:
It is… Read the rest
Retro Z80 computer (10) – Pi-Terminal
I got one of my raspberry Pi’s out of storage and made it to be a terminal for the Z80:… Read the rest
Retro Z80 computer (9) – BLINKENLIGHTS
A small project today. I added ‘BLINKENLIGHTS’ to my Z80. This term stems from an old sign that used to hang in computer rooms:
ACHTUNG!ALLES TURISTEN UND NONTEKNISCHEN LOOKENSPEEPERS!DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKEN.IST NICHT… Read the rest
Christmas in the shack
Do you guys also get the Christmas feeling and make it visible in your shack / workshop? What do you think, is an image like this recognizable? I do…
Xmas shack… Read the rest
Retro Z80 computer (1) – plans
This holiday season I’m going retro, and build my own Z80 computer from a kit. The kit offers all the separate parts and one has to assemble the whole thing…
All the parts
Modular design
The design of this computer is totally modular. Because it has been thought out very… Read the rest
Resonance measurements / filters
Yesterday I started with Capacitors / capacity and coils / inductance. Today I did some extensive measuring, first on a C and L in a series tuned circuit, then on a parallel tuned circuit. See schematics here below:
For these measurements I used the same setup as yesterday. But this… Read the rest
Resonance frequencies
In the HAM course I am following to become a licensed radio amateur, the topic of resonance frequencies came along. To wrap my head around it I did some experimenting. You can find the result below. I have an assortment of capacitors and coils that I can use for these… Read the rest
HAM-gadget (6) – adjustment & enclosure
In this version I built in the possibility to adjust the summer and wintertime offset from UTC. It’s a very crude offset, I just add or subtract the offset from the UTC hour. Have to think of a better way to do this…
Enclosure
I built in the gadget in… Read the rest
HAM-gadget (5) – menu structure
This weekend I built in a menu structure into the HAM-gadget. Also I created a possibility to store and retrieve settings to the ATMEGA328P’s EEPROM, so they are saved for the next time you switch on the device. For now, you have to retrieve them manually, but that’s quicker then… Read the rest
HAM-gadget (4) – keyboard added
After a lot of fiddling, trial and errors, I finally got the matrix keyboard to work. Also, as the project has passed the prototype stage, I threw together everything on a PCB in preparation for mounting it in a casing.
Note to self:next time first cut the PCB to size… Read the rest