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
 Receiver Topview |
 First Mixer |
 Frontend Filter |
 PreAmplifier |
 Detail (TCA440) |
 Demodulation |
 Audioamplifier |
VHF UHF Receiver out of the junkbox.
The receiver is built with the tuner UV916E and the ICs TBA120, TDA1072 and TBA810.
Exact data unfortunately no longer exist.
 RX in open case |
 Modules of the RX |
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
 RF/ZF Moduls |
 Top View |
 Rear-Inside |
 Front Topless |
After a long time I worked with tubes again in 2003 and built a simple audio amplifier with the tubes ECC83, EL34 and EMM803.
 Amp Design |
 EL34 Modul |
 Amp Test 1 |
 Amp Test 2 |
 Amplifier |
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.
 Development Board |
 Detail 1 |
 Detail 2 |
 Modul Overview |
 μC Modul 1 |
 μC Modul 2 |
 ISP Modul |
 RS232 Modul |
 Experiment Modul |
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.
 Frequency Counter |
 Inside View |
 Schematic 1 |
 Schematic 2 |
 Building Blocks |
 RX Rear |
 RX Front |
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 (again) nowadays are e.g. a small
transmitter for VHF broadcasting from 1975, a simple electronic drum kit
from 1976, a vertical amplifier (1976) for a simple
oscilloscope with the 3BP1, a audio
preamplifier and a power supply for a Audio Amplifier Kit from 1976. Also
found an LF amplifier was a LF amplifier with preamplifier, power amplifier and
power supply from 1977, as well as a Dynamic Noise Limiter (DNL) from
1977. From 1977 there is also a timer/clock with the IC
MK50362 from 1977. This IC was very modern for that time. The time
base, which was derived from a 1 MHz crystal, still works today. From the year
1979 I found another small audio amplifier. Also from this time is a
regulated laboratory power supply (with the draught horse of electronics,
the famous 2N3055).
 197x Retrotronic |
 Transmitter 1975 |
 Drumbox 1976 |
 Vertical Amp 1976 |
 Audio PreAmp 1976 |
 PSU for Audio Amp 1976 |
 Audio Amplifier 1977 |
 Audio Amplifier 1977 |
 Audio Amplifier 1977 |
 Dyn Noise Limiter 1977 |
 Clock Time Base 1977 |
 Clock Radio Timer |
 Clock Radio Timer |
 LPSU front side |
 LPSU inside |
 LPSU circuit board |
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.
