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Donate me your old
electronics (components, radios, etc.). I
use these to build new projects! |
Circuits and Projects
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Radio-related
 Antenna
noise blanker NR-1 
 Simple harmonics generator for HF signal generators
 Fixing and modifying the Tektronix 491 attenuator
Simple and effective HF preselector
Heathkit SB-650 and Collins KWM2-A
Tektronix 190 restoration and modification
Modified Tektronix 190 active probe addition
Current limited variac
FRG-7
digital display contrast improvement
HP8601A
loop hybrid reproduction
Collins
51S-1 bandscope
Converting
the FRG-7 to true
SSB (all mods)
Low
voltage tube crystal oscillator
Low
voltage tube RF preamplifier
Bucking
transformer 240V to 225V
An
all-bands random wire antenna
KISS703.
A new mode for the HAM
sv3ora's
ultra minimalist transmitter
 A
15-components versatile
keyer and powerful PSU modulator for the EMTX
Rigs selector and
automatic
antenna switch
for your shack
All HF bands
transmitter (experiment)
Installing a
mechanical SSB
filter on the FRG-7
Tune
your FRG-7 to true SSB
Correcting
the fine tune in the FRG-7
RF power switch for
your rigs
Classic 40 CW/AM
transmitter
Emergency
transmitter - A 8-components
high-power 40m/30m transmitter to get you quickly on the air
The
brilliant
"miniVFO".
As stable as a crystal and mini!
Dimming
the panel
lights on the
Yaesu FT-301
Add general
HF receive
coverage to the
Yaesu FT-301
HF DSB walkie
talkie
Simple all
bands superhet CW receiver
DDS DSB/AM
receiver 0-60MHz
Mini AM
transmitter
The all waves
RX powered by 1.5v
DDS VFO
0-60MHz
The "Super VFO".
As stable as a crystal
Simple MCU-free
HF frequency counter
Improving
the Albrecht
AE2990AFS
Easy and
reliable bfo
A cheap and
easy all hf bands transceiver
A
broadband
concept receiver that will amaze you
HF+6m
active
antenna for the Kenwood TH-F6/TH-F7
HF all bands
handheld transceiver for the radio amateur
An easy to build
UHF TV
modulator
Single
signal
reflexed regenerative receiver
All-bands
single-signal
filtered regenerative detector
Universal,
very low
distortion, HF broadband crystal oscillator
Vacuum
tube microwave oscillator (Greek)
All
about LPD/PMR transceivers (Greek only)
Wide range
quadrature oscillator without DDS
easy40 - A
14-components
high-power transmitter to get you quickly on the air
A
2-components
oscillator
High
dynamic
range
broadband LNA for handheld transceivers
Preamplifier
switching and bypassing using RF as control
HF
directional coupler
Broadband
CW QRPp HF transmitter
Ultra low
noise, low distortion, general purpose LF/MF/HF oscillator
All HF bands
low distortion
sinusoidal XO
The
ultimate QRP HF
transceiver
A simple,
good quality UHF
TV
modulator
An
easy
to build all HF bands discrete SSB transceiver
In-phase
splitter/combiner
4:1 balanced
to
unbalanced
balun
 Magnetic
receiver
Fine tuning
the SM0VPO HF
amplifier
for better performance
The
fully transistorized radio project
Smart
KIT 1W FM transmitter reverse engineered
Single
span,
high
spectral
purity oscillator 3KHz-30MHz
A
simple to assemble regenerative SW receiver
HF
all-band
tuneable bandpass filter
1-30MHz
deluxe crystal controlled CW/CDW transmitter
1-30MHz ultra
low noise
and distortion crystal oscillator
Control the
transmitter from the computer
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Digital-related
 CB2 micro - perhaps the
easiest to build micro in the world
Bell
103 multi-interface modem
micro
SD locker and instructions for a safe PC (Greek only)
The
ATLAS computer
A
single chip micro-computer for the lab
A
universal variable VCO
clock
Reverse
linear
ramp, sawtooth generator
Saturable
inductor
amplifier (an invention of mine)
Diode
amplifier (an
invention of mine)
Core
rope memory
Coincident
current NOR
gates
Experiments
on square loop toroids
A
transistorized 4-bit digital computer made out of discrete DTL
(in
development)
A
full-sized
microcomputer inside a keyboard
Development of a Tele-control Home Appliance
Controller (my MSc project)
First pages, Main
report, Schematics
and
datasheets
A
simple,
failure
immune 4-bit digital computer made out of common TTL chips
(in
development)
The
ZX-80 computer (A useable home computer built REALLY from
scratch.
This includes PCB etching)
The
Jupiter Ace computer (A useable home computer built REALLY
from
scratch. This includes PCB etching. In development)
Reverse
engineering of the Vectrex system (The unique vector graphics
system and how to build one yourself from scratch)
The
homemade PC-XT project (A greater scale PC-clone home
computer.
Some parts are in KIT form. In development)
Audio-related
 Le
Monstre Class-A solid state amplifier (capacitor-less)
Ferrari
Class-A 2A3 PSE (Ciuffoli's design)
Diamond
PC88 Class-A line preamplifier
Audio
compressor
The
vacuum
tube poly-synth project (VCO section)
QRP
audio amplifier
The
magical audio filter refined
Other
electronics
Electromechanical
"magic eye" display
Vibration
activated LED
charge pumps
High
power thrifty
regulator
A
simple and
cheap UPS
UPS
for
ADSL
routers and embedded systems
Personal
ballooning - A
pioneer flying concept
Experiments
for
Energy Harvesting and Efficiency
 A
blinking LED
Christmas
tree
 The
LED Zapper game (a game for the blind or
the deaf)
The
SkyNet
project (Low data rate laser data links, in
development)
Alcatel BF4
(One Touch
511)
information
Natural radio
 The sounds of the earth
and other
natural sources and simple equipment
E-field VLF
natural
radio
receiver
H-field
VLF/ELF/ULF
natural
radio
receiver (in development)
Mechanical-related
Repairing
the tuning knob of
the IC-728 transceiver
Increasing
the capacity of the Unimat SL (DB-200)
Making a
special knob for
tuning the DDS in a handheld transceiver
A depth gauge
or
Z-axis meter for the Unimat-SL (DB-200)
Making
a
special
screwdriver for the lab (under development)
A table for the lathe
How to mill
an
enclosure on
a small lathe (part of another project)
Experiments
on the olive
oil fuel
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Electronics and RF
techniques 
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Idea for a simple wire recorder
Notch
to BPF conversion
Hacking
the GSM
codecs to pass FSK data through
Lead-free solder
comparison. SAC305 vs
SnCxPlus07
Wheatstone bridge
splitter/combiner
construction and measurements
Using capacitors as varicaps
Holder
for RF toroids
Transformers
winding on HF in-phase splitter
BJT negistor
applications
Salvaging
electronics components for
QRP projects
Common mode
chokes in boost converters
Exponential
RF amplifier for reducing
harmonics without filtering |
Crystal oscillator oscillates
in more
than one frequencies simultaneously!
An
adaptable
crystal set
that has
it all?
Homebrew
your
own SiC
LED
Reliability
of data storage media
A
generalized prototype board for digital electronics work
The
simplest way to program and read the PIC16F84 MCU
Measuring
and
selecting the actual received frequency in regenerative and direct
conversion receivers
Ultra
narrowband adjustable
shape and bandwidth crystal
phasing filter
Making
precision PCB coils
Experiments
on
circuits on
paper - Dwawn resistors
Homemade film
capacitors |
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Poor man's
laboratory equipment 
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RF
test jig
Detector
probe
The super probe
miniaturized
Quick and easy
marker
generator
All
waves RF
generator
Potentiometer
noise tester
3-30MHz
signal
generator based
on the brilliant
"miniVFO"
Simple MCU-free
HF frequency counter
High range
LED meter display
Quick
components tester
HF crystal
tester
Versatile
oscillator/demodulator instrument (in Greek)
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Ultra
wideband sinusoidal VFO with AM capability
A handheld
multi-purpose
meter for the HF experimenter
A
low
profile lamp designed specifically for SMD rework
Poor man's HF
spectrum analyzer
A BASIC
computer designed
especially
for lab use (in development)
A low
frequency
circulator/isolator
A mini
reference oscillator
A return
loss bridge for
impedance
measurements
A mini dummy
load for impedance measurements
Solid
state
UV PCB
exposure
Semiconductor
analyzer
(For BJTs, mosfets and diodes. An Elektor project)
A
homemade UV exposure box for big
double-sided PCB fabrication |
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Software
I have
developed (and other useful software)
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Schematix.
Schematic drawing and exchanging for the radio amateur
Morse
code
encoder/decoder
Modified tap
code
encoder/decoder
DataText.
Transfer data through any radio amateur text mode
The
CDW communications mode (version 2)
TAP,
a morse alternative mode for the HAM
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JLab
- an
online electronics software suite
How
to draw
ARRL-style schematics
The
XDOS
A
complete software TNC for the radio amateur (other's project,
documentation by me)
NBTV
programs for the radio amateur (other's projects) |
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Theory, information and
tutorials
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5-9 Report
(archived Greek amateur radio magazine)
Set up your own dial-up server (vintage networking through
telcos)
RF radiation and electroagnetic field safety
Assembly
tutorial and information
Diodes
evaluation
for
crystal sets - A simple test
A
tribute to the watch movement
A tribute to
the wind-up gramophone engine
Linear
UHF vacuum
tube
circuits
Vacuum
tube
television
General
diode applications
All
diodes transceiver
Passive
crystal receivers
Tunnel
diodes
Varactor
diodes
Schottkey
diodes
Rectifier
diode audio amplifier
Passive
DSB transmitter
Passive
CW transmitter
Ferrite
core mixers
Magnetic
amplifiers
Transformers
Electromechanical
transmitters and receivers
Neon
lamps
Radar
history
The
phasitron tube
Thermoelectric
generator
Analog
computers
Logic
gates technology
5000 IC audio
amplifier circuits
My
designs on electromechanical
transmitters for LW
RCA
power tubes comparison handbook
The myth of
reflected
power
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TV
transmitters
SSB
transistorized CB
Barlow
Wadley loop
Radio
spectrum frequency allocation chart
dBm, mw, Vpp, Vp,
Veff conversion table
Optimum
wire size for RF coils
Observations
on ferrite rod antennas
Designing
wideband transformers for HF and VHF power amplifiers
Crystal
parameter measurement and ladder crystal filter design
Quartz
crystal parameter measurement
Crystal
filters with variable bandwidth and constant center frequency
Easy to
build
crystal ladder filters (page26)
Ultra
low noise active devices on a
budget
74LSxx series chips
internal schematics
Common varicaps
in radio
RF
mixers explained. Part
1, part
2
and part
3.
Understanding
mixer products
AM/SSB
modulation and peak envelope detector
Calculating
transmitter efficiency
Measuring
transmitter power, do and don't
Harmonics
generation using step recovery diodes (HP)
Understanding
noise types in oscillators
Motorola
master selection guide - Small signal BJTs, FETs and diodes
Voltage
controlled capacitance without varactors
IARU
region 1 VHF
and up band plan
IARU
region 1 HF Europe band plan
IARU
region 1 HF band
plan
Aeronautical
HF radio map
Greek
spectrum
allocation
Fundamentals of
electronic
counters |
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Useful
Links
|
 Dc4ku
website. Measurements and RF (only in German)
Great
RF experiments website
S53MV
website.
Microwave and advanced RF projects.
JF1OZL
website. Archived from www.intio.or.jp/jf10zl
Greek
Microwave Group
website. Amateur group for microwave radio projects.
YO3DAC -
VA3IUL website.
Amateur radio projects.
LA8AK
website.
Amateur radio projects
SM0VPO -
G4VVJ website.
Amateur radio projects.
Hans
Summers.
Radio, Electronics and Computing Projects.
QRP
and SWL
homebrew equipment.
Cool
homemade stuff homemade electronics components.
Digital modes
experimenter website.
My professional website.
Elm
Chan website. Great microcontroller projects.
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Freddy
Alferink website. All about accurate measurements.
Radio waves below
22KHz.
Simple QRP
equipment
Homebrew
electronics from Germany
QRP4u
Circuits from
Russia
Circuits from
Czech
Useful
radio amateur scanned circuits
Useful
ham scanned circuits
Electronics
Circuits Reference Archive
HF propagation prediction data
Web
SDR - Listen to DC-30MHz without an RX
Glen's stuff. Some of the most advanced
projects.
Cool386. Very nice tube projects.
 Visit my
QRZ page to see my gear
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Contact me
|
 E-mail
me
 The
email to contact me is:
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 Enter the CB2 micro BBS
It
runs from a
microcontroller!
(Located at Patras city, started on late 2021)
Connect by
Telnet: cb2.qrp.gr:2323
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Disclaimer |
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You are free to copy and use
everything on this non-profit amateur website. Note that for
copyrighted material, you may need to ask for the authors permission
first. All material on this website is provided as is without any
guarantee. Many of the material is my own thoughts and do not
necessarily represent the truth. It is provided for you to read in
order to understand the basic principles of operation. If you find your
material is listed somewhere in this page and you want to
remove it or
get credit for it, please let me know and I will remove it immediately
or add relevant notes. You may copy and use any content of this website
to other pages, only if you clearly include in your pages the source
that it has been taken from (which is this website). You may build and
use any project only at your own risk and you are the only one that are
responsible for its use. You should always consider your country
regulations before building anything. I am
paying lots each year for
maintaining this website and you get that for free, please gain
knowledge from what you find here and be reasonable about copyright
stuff anyway. Contact me FIRST before you make any nasty post anywhere
on the web about my website!
Website
intentionally built using web 1.0 technology
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