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Projects before 2005

R2004 Receiver

LW/MW/SW receiver with AM/LSB Demodulation. (2004)

Frequency Range: 100 kHz - 10 MHz
50 Ohm Antenna Input
10 MHz LPF
Switchable Attenuator/PreAmp (2 x 2N3819)
1. Mixer: Homebrew Diode DBM
DDS LO up to 20 MHz (DDS Kit) / Driver +16dBm
1. IF = 10.7 MHz, SFE 10.7 Ceramicfilter
2. Mixer + IF-Amp: TCA440
2. LO: 10,245 MHz Quartz Osc. (BF199) 2. IF = 455 kHz
Switchable filter: U455, 2 x SFZ455B, 2 x xCFW455HT
Productdetector: NE602
Audio BPF: 350 - 3.5 kHz
AM-Demodulation: Fullwave rectifier (LM318) or with TV chip (TDA8341)
Audio selector (74HCT4066), AF Amp (TDA1905)
Soundcard Interface (TL071), DRM Interface (NE602)
PowerSupply: +12 V and +5V

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Receiver Topview
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First Mixer
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Frontend Filter
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PreAmplifier
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Detail (TCA440)
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Demodulation
r04audioamp.jpg
Audioamplifier
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ScrapRig Receiver

Simple 20m Band SSB Receiver out of the junkbox. (2003)

Frequency Range: 14 MHz - 14.350 MHz
20m BPF
1. Mixer NE602
VFO: 9.5 - 10 MHz (2N3819 + BF245)
IF = 4.433618 MHz
Ladderfilter: 4 x 4.433618 Quartz
BFO: 4.433 MHz
Productdetector: TBA120
AF-Amp

scraprig_1.jpg
RF/ZF Moduls
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Top View
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Rear-Inside
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Front Topless
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Tubes Amplifier with EL34

After a long time I worked with tubes again in 2003 and built a simple audio amplifier with the tubes ECC83, EL34 and EMM803.

 

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Amp Design
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EL34 Modul
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Amp Test 1
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Amp Test 2
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Amplifier
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MCU Development Board

Microcontroller units (MCU, μC) are widely used to control various electronic devices, to calculate data or to measure values. In 2003 I built a development board to familiarize myself with this interesting subject. The Atmel AT90S2313 was used as a simple 8-bit MCU. For this purpose, various modules such as an RS232 connection and an ISP programming interface or an LCD display etc. were added. An experimental board with different components such as push-buttons, potentiometers etc. is used for experimenting. With this developer board I have acquired the basic knowledge of μC programming.

 

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Development Board
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Detail 1
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Detail 2
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Modul Overview
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μC Modul 1
switch.jpg
μC Modul 2
ISPmodul.jpg
ISP Modul
RS232modul.jpg
RS232 Modul
ExpModul.jpg
Experiment Modul
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Frequency Counter

A simple frequency counter with a CMOS IC (ICM7226) has been extended by an amplifier and a prescaler (built 2002)

The ICM7226 BIPL is a fully integrated universal counter and LED display driver. It combines a decade timebase counter, an 8-decade data counter and latches, a 7-segment decoder, digit multiplexer and segment and digit drivers. The IC counter inputs accept a maximum frequency of 10 MHz digital inputs.

 

FC01.jpg
Frequency Counter
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Inside View
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Schematic 1
FC04.jpg
Schematic 2
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VHF RX with analog TV sound demodulation


TVS01.jpg
Building Blocks
TVS02.jpg
RX Rear
TVS03.jpg
RX Front
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Retro Electronics

My first "projects" were detector receivers and simplest electronic circuits I had built as a boy with about 12 years. There followed receiver and amplifiers with tubes and with first transistors.

The oldest projects I could find today were, for example, a clock with the IC MK50362 from 1977. That was very modern at that time. The time base derived from a 1 MHz quartz is still working even today. A small transmitter for the VHF broadcasting area dates from 1975 and a small audio amplifier was built in 1979.



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Retrotonic
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Time Base
Retro03.jpg
Transmitter
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Clock Radio Timer
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Clock Radio Timer

 

From 1970 until today innumerable devices were recreated or developed. Almost everything has disappeared and has not been documented. Since then, many years have passed, but the fascination has remained.

 

 

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