Thomas Martin, DF7TV, Stuttgart, Germany

Hello and Welcome!

My 'on the air' name is Tom and these pages are dedicated to amateur radio.

DF7TV 'On The Air'

Being a member of the Amateur Radio Club at the University of Stuttgart, I am QRV at the club station.

The biography of DF7TV at QRZ.COM shows an up-to-date description of the equipment used.

DXing

In February 2017 I began to make more contacts with other amateur stations from different countries/DXCC entities. My first aim was to get confirmed 100 different entities and become a member of the coveted DX Century Club (DXCC) of the American Radio Relay League, Inc. (ARRL). On May 15, 2017 my membership (CW #23,108) in the DX Century Club was attested by the ARRL. Since then I have been working to add additional entities. DF7TV DXCC CW award

Working all Areas of a Country

Apart from working new DXCC entities, I like to work all areas of a country. DF7TV-Prefectures-of-Japan-Confirmed-Mode-CW

DF7TV-States-of-the-USA-Confirmed-Mode-CW

Keymen's Club of Japan Award (KCJA)

Morse Code Training (25+ wpm)

Morse Code Training shows a way of improving Morse Code proficiency at speeds above 25 wpm.

Morse Code Processing

DF7TV: Symbol to label the side tone output socket

Morse Code Processing presents some circuits and software related to Morse Code signals.

Experimenting

The sineCW60 — Regenerative Code Practice Oscillator (software) provides a configurable Morse Code monitor tone of high-quality.

The WK3 WinKeyer Side Tone Output Modification to the K1EL WK3 WinKeyer provides a square wave monitor tone via a 3.5mm 3-pole output jack.

An RF Bias-Tee has been designed and built for a local club station. It includes a cascade of four inductors (L1 to L4), optimized to result in a high-impedance broadband choke (1 to 150 MHz).

Frank M Doerenberg, N4SPP provides in-depth information and extensive references on the Multi Band End-Fed Antenna. His publication helped a lot during the design and construction of a 160 meter band Sloping End-Fed Half-Wave (EFHW) Receiving Antenna at a local club station.

For a while, I have been experimenting with the K3NG Arduino CW Keyer. This keyer includes the option to set the keyer speed by a rotary encoder. In the original code, you may choose between "Full-Step" and "Half-Step" transition tables for the encoder. I have written additional code for a "Quarter-Step" state transition table. It is published as Quarter-Step_State_Transition_Table_for_Standard_Quadrature_2-Bit_Gray_Code_Rotary_Encoders.pdf. This code seems to support my rotary encoder (Grayhill 61C11-01-08-02) in a better way.

Wes Hayward, W7ZOI described (QST Magazine, June 2001) an RF power meter based on the AD8307 Logarithmic Amplifier and inspired me to build my PM8307.