Electronics Projects of Tom Ahola

Here is a gallery of a small fraction of my many electronics projects during the past years. All are my own designs. My main interest has always been in designing, not building gadgets. Click on the pictures to enlarge them. Some are old pictures of low quality. Unfortunately there are no records of my earliest designs that I made at around 11-12 years of age.

As a kid I started with simple battery-switch-lightbulb circuits. But soon I started experimenting with transistors and electron tubes. Printed circuit boards I learned to make at age 14. I had built a simple oscilloscope from an old black & white television. The large screen was impressive but the speed and accuracy of magnetic deflection was inadequate. When I turned 16 I had saved enough money for a real oscilloscope. I still use this 60MHz 2-channel analog oscilloscope every now and then, but nowadays I have a modern computer controlled electronic measurement environment. One of my special skills is in Test & Measurement system development. My system consists of a multitude of instruments such as power supplies, multimeters, signal generators, RF network analyzer, RF power meter, digital oscilloscope and frequency counter. I have made test software that can quickly do various sweep measurements, controlling simultaneously several of my instruments and doing measurements and plotting results.

I also build Radio Equipment and Antennas. See my Amateur Radio page: OH2FRM. There are only a few antenna pictures there under my location. I might add more in the future.

Do check my CV. I'm always open for new challenges and projects.

I have made some online tools available, useful for electronics design


Adjustable current sink with low voltage cutoff

Retiring the SCSI hard drive from my Kurzweil K2500S and replacing it with an SD card

NWSP : Nokia Wrist Attached Sensor Platform

All my Sensor Platforms

KAU-93 : Control Electronics for an Iodine Stabilized He-Ne Laser

DiLS : Digitally Stabilized Laser System

Z11 : Modular Analog Synthesizer

MSA-68 : High end Tube Modelling MOSFET Audio Amplifier

GRC-188 : A 18 bit Analog-to-Digital and Digital-to-Analog Audio Converter

DSP950924 : A High performance DSP PC-AT Board with digital audio in/out

PIC024003 : Computer controlled telephone with automated dial-up feature

TGA-22K : Audio signal generator

Precision temperature controller for iodine cells

PIC032407 : Camera shutter control unit

Digital drum pad

Portable low noise balanced microphone amplifier

Optical threshold switch

DSP9000 : Audio DSP realtime effects unit

Digital Audio format changer and switch

TAS-880 : Computer Audio Interface (ADC and DAC)

Underwater camera with stereo hydrophone

Picotector : High sensitivity photodetector for optical power measurement

PHD-960401 : Photodetector amplifier

TAM-984403 : Sampling voltmeter

Optical active motion detector

Computer backup power supply

Low noise condenser microphone preamplifier with phantom voltage feed

HiFi Balanced audio pre-amplifier

Adjustable audio attenuator

Multimedia audio power amplifier

Sweepable sampling voltmeter

Multitrack cassette recorder

Multimedia computer

24 bit Audio AD converter and digital audio sample rate converter

SPDIF digital audio patchbay

Digital bus PC interface board

PC-AT bus diagnostic board

108 dB Sound System


These boards are from the 1980's when I did use a decon-dalo ink pen to draw the resist on the board by hand. I was a young kid then. My very first boards from the beginning of the 80's I don't have any pictures of. My first boards I etched using the very dangerous Nitric Acid HNO3, which emits poisoneaus fumes and can be used to make explosives. These days kids would not very easily get access to that kind of chemicals. Later I used Ferric Chloride FeCl3, which is less dangerous. In the 1990's I started using photoresists to make more accurate boards with higher density.

©2008 Tom Ahola