AMATEUR RADIO
Antennas
Last update : 24 October 2026
- DF9CY Simple USB/RS232 CW Interface for contests
A very easy and simple interface for CW keying your transceiver via the RS232 port. Use a Prolific/FTDI USB/RS232 Adapter, if your computer does not provide a RS232 port. PDF file download.
(24 October 2026) - DF9CY 7 Element Antenna for 50 MHz (Version 2)
Proven concept for a high performance 7 element yagi design antenna for 50 MHz. Complete description. PDF file download.
(08 September 2022) - OP-DES 6 element 50 MHz (G0KSC)
Antenna simulation of a 6 element OP-DES (Opposite Phase Driven Element System) antenna. I have put this antenna on my tower in February 2021
(13 March 2021) - Simulation of a 50 MHz EME antenna using the 6 Element OP-DES (G0KSC)
Antenna simulation of a 4 * 6 element OP-DES moonbounce antenna for dreamers. Just hypothetical ...
(15 March 2021) - DF9CY
Antenna Comparison Chart File (ACCF) for 432 MHz
Antenna simulation results for 432 MHz antennas. PDF file download. For 50 MHz and 144 MHz I recommend the VE7BQH tables. !!
(08 June 2010) - ZX 6-7 Yagi Antenna for 50
MHz
An extended version of the ZX Antenna with now 7 elements. Since June 2012 a stacked system is operational.
(07 December 2012) - Some popular 432
MHz EME antennas
Looking for an antenna design for a 432 MHz EME system, I made this comparison.
(19 December 2008) - ZX 6-6 50 MHz Yagi
Antenna
This is a simulation of my antenna I use now for the 6m band
(2 June 2008) - DF9CY 432 MHz 9 Element
Yagi Antenna (DK7ZB Type)
This describes a 9 Element DK7ZB Type antenna I "recalculated" and successfully built.
(20 May 2008) - DF9CY 40m Noise
Reduction
I describe, how I greatly reduced the noise getting into my shortwave receiver by using common-mode chokes.
(7 April 2008) - DF9CY EZNEC
Antenna Simulation files collection
A collection of antenna simulation files you will get here.
(last updated 15 May 2008) - DL6WU/DF9CY 432 MHz 11 Element
Yagi Antenna
I designed a new compact antenna with good performance based on the proven DL6WU design.
(1 April 2008) - DF9CY Extended 4 Element
Antenna 21 MHz to 28 MHz
An extension to an existing ZX-Yagi 15-4 to 28 MHz by adding another 4 elements on the same boom. (Including EZNEC and NEC2 files)
(25 Jan 2008) - 137 MHz NOAA Turnstile
2x2 Element
I have an antenna for 137 MHz NOAA wheather satellite reception. Here is a simulation I made with NEC2.
(21 Nov 2007) - 432 MHz 10 Element Yagi
Antenna
This is a 2 wavelengths antenna for 432 MHz. Here is a simulation and an optimization of this antenna made by Winkler Antennen. I used this antenna for a while.
(20 Nov 2007) - DF9CY Full-Size
Vertical for 7,05 MHz
In 2006 I had this full-size vertical up for a while. Now I simulated the antenna with some astonishing results when comparing it to the dipole antenna.
(20 Nov 2007) - DF9CY Wire Dipole for
7,05 MHz
Here is an antenna for the 40m band. Centre is 12m up with somewhat lowered ends of the two legs.
(31 Oct 2007) - DF9CY 6 Element 50
MHz (Long Version)
This article describes a six element antenna for the 50 MHz band, which has a significantly improved performance over my old design (see below). I used it a while ago with good success.
(01 Oct 2007) - DK7ZB 9
Element for 144 MHz
Description and Simulation of the antenna
(13 Mar 2004) - Medium Wave
(MW) Simple Active Antenna
Schematic diagram of an active magnetic antenna I have built for Medium Wave reception - esp. DRM
(9 December 2003) | only SCM - A tiny well-performing Three
Element Antenna for 28 MHz
A description of my 3 Element Antenna for 28 MHz with EZNEC file and diagrams. - The DF9CY SIX ELEMENT Antenna for
50 MHz
This article describes my 6 element antenna for the 50 MHz Amateur Radio Band, which has some significant improvements over the 4 element antenna. Included are the dimensions, some results, diagrams and the downloadable EZNEC file. - DF9CY Four Element Antenna for 50
MHz
An article about my two stacked homemade 4 element antenna for the 50 MHz Amateur Radio Band. (FUNKAMATEUR 4/1997 p.448+). - The Konni-Antennen 5
Element Antenna for 50 MHz
Here is a brief description and the simulation with EZNEC. - The "Leonid Magic"
for 50 MHz
Short time before the Leonid meteor shower of 1998 (the big one) I had the idea of pointing an antenna with a broad main lobe straight up into the sky. I it was really a big success. Here is an image of this antenna.
Weak Signal
- SDR-IQ and Linrad
screenshots
First impressions of the Linrad software running with the SDR-IQ receiver on shortwave.
(01 March 2010)
RF Design
- Improving
Receiver Noise on 50 MHz
What is the advantage of mounting a low noise preamplifier at the antenna ?
(06 August 2009) - TenTec 1208CY 50 MHz
Transverter
6m Transverter for my 50 MHz Transceiver (see below) with modification to 10 MHz IF.
(12 March 2008) - Softrock 6.2
RXTX + 50 MHz Transceiver
SDR Transceiver Project for 40m/30m and 6m.
(12 March 2008) - Softrock
Version 6.1 RXTX Software Setup
Software Setup for the Softrock 6.1 RXTX project to get all the stuff running.
(21 September 2009) - SoftRock
RXTX 6.1 Software Defined Transceiver
A tiny high performance transceiver with IQ in/out for 40m and 80m with 1.2W output (measured on 40m Band)
(21 September 2009) - SoftRock V 6.1
Software Defined Receiver
A tiny broadband receiver with IQ out for SDR 0 Software Defined Receiver experiments.
(10 October 2006) - DRM
Demonstration Receiver
A simple but effective receiver for 100 kHz .. 30 MHz with 12 kHz IF for Digital Radio Mondiale (DRM).
Status: Design Phase | Version 2.0 (29 March 2005)
Download schematic diagram of Version 0.2 DDSR1
Download schematic diagram of Low Noise Version 2.0 DDSR2 - ICOM820H
Soundcardinterface
Here is the schematic diagram of the soundcard interface I have built for WSJT for my VHF Transceiver ICOM 820H
(9 December 2003) | only SCM - 432 MHz Low-Noise GaAs-Fet
Preamplifier
This describes a low noise amplifier beeing suitable for serious 432 MHz Moonbounce work and weak-signal reception. The design can be transferred to 144 MHz and 220 MHz. - DF9CY TVI-Stop filter for
all bands
Problems with your ham radio in your neighbours' TV set ? Here is a very good and cheap solution for your problem. A real Peacemaker ... - 100 MHz Broadcast Bandpass
Filter
Passband filter for the 100 MHz broadcast band to insert in front of VHF stereo receivers. - "Magic
Fifty"
My 50 MHz transverter (144 MHz input) which I developped in 1990. It is completely in SMD technology. A reprint of the DUBUS Articles from 3/1991 (part 1). German & English and The Addendum 1/1993 (part 2).
Microwave
- 24 GHz
Transverter
Some information about my 24 GHz transverter can be found here.
(11 April 2008)
Showcase and Reviews
- Tablet Computer with
Android Operating System
A view inside an Android based Tablet computer (Hannspree Hannspad 10T)
(11 October 2011) - Sommerkamp FT250
A Nostalgia Sommerkamp FT-250 came "along the way" ... Here are some images of this radio, which is fully working.
(25 January 2008) - TenTec RX320D
Modifications and an overview and a lab-test of my PC-only controlled 100 kHz to 30 MHz receiver. (09 June 2004) - KENWOOD TS690S
A lab-test on my all-mode transceiver for shortwave and 50 MHz (An article I wrote in 1991 for "Funktelegramm" - in German and English).
Added a HOW-TO expand the TS690 for 30 kHZ to 60 MHz coverage.
Other
- LINRAD
Installation
Installation of Linrad - a software radio - under SuSE Linux 9.1. Works on Knoppix 3.7 too. (16 May 2005)
- BEMFV 144 MHz
Feldstärke Messungen (D)
Messungen an meiner Amateurfunkstation auf 144 MHz mit Richtantenne (2004/12.2007)
For technical articles on Astrophotography see on ASTROPHOTO-PAGES
Software
- DOWNLOAD PAGE
All software projects and Spreadsheets are on this special download page