Electronics – Geronimo/370

Another new clock

Posted on2023-07-16

Remember that Making a new clock (1) blog post? That one was to honour my dad’s old nixie clock. It’s in my office / HAM shack. Now we wanted another clock for another room. I decided to use the same parts and the same software, but built it a lot… Read the rest

Making a new clock (1)

Posted on2023-01-022023-01-202 Comments

As you could have read in my previous post, I decided to create my own digital clock to replace the old nixie clock (R.I.P). Components The components I will be using are: The casing of the old nixie clock An Arduino Uno (for programming the ATMEGA328p chip. Actually that chip… Read the rest

Fixing old Nixie Clock (3) ?

Posted on2023-01-021 Comment

Well, maybe you remember the previous posts about my dad’s nixie clock? I was very satisfied when I got it working again. Now, after 8 months it finally broke down completely. Oh well, it lasted for (I think) over forty years! New beginnings I decided to take the guts out… Read the rest

Fixing old Nixie Clock (3)

Posted on2022-04-282022-04-28

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

Fixing old Nixie Clock (2)

Posted on2022-04-232022-04-233 Comments

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)

Posted on2022-04-102022-11-22

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)

Posted on2022-02-182022-02-25

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)

Posted on2022-02-182022-02-18

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)

Posted on2022-02-132022-02-181 Comment

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

Posted on2022-01-262022-01-26

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

Posted on2022-01-212022-01-21

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

Posted on2021-12-272021-12-27

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

Posted on2021-12-112021-12-15

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

Posted on2021-12-052022-03-02

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

Posted on2021-12-042021-12-041 Comment

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