Thomas Martin, DF7TV, Stuttgart, Germany.

Hello and Welcome!


DF7TV (Tom) is a radio amateur 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. I am also qrv from home or portable using simple wire antennas but I admit that using the club's antennas is a lot more fun. The biography of DF7TV at QRZ.COM[6] shows an up-to-date description of the equipment used.

Morse Code (CW)

CW Academy: Giving Back program

I am an operator within the on-air Morse Code coaching program GIVING BACK (GB)[4] of the CW Academy (CWA); QRV on Wednesdays from 20:00 UTC to 21:00 UTC. By sending "CQ CQ DE DF7TV DF7TV GB K" I am calling on the 40m band (7037 kHz +/- 2 kHz) or on the 80m band (3537 kHz +/-2 kHz). Access to our club station at the university is limited due to the pandemic. So it may happen that I am not QRV on shortwave bands during the announced time for GIVING BACK.

If you like to practice Morse Code and if you are QRV on iCW -- Internet CW[9], [10], we may have a conversational QSO at your preferred speed (below 30 wpm) on iCW -- please send me an email to fix a SKED.


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.


Working all Areas of a Country

Apart from working new entities I like to work all areas of a country. Here are my results for Japan (47 Prefectures) and the U.S.A. (50 States).


Elecraft K2

Building Elecraft[1] K2 transceiver kits is fun and so I built serial numbers 2383, 2759, 3105 and 4138. Some information about my latest K2 (S/N 4138) is presented.

Sverre Holm, LA3ZA provides an excellent unofficial guide to Elecraft K2 modifications[2].

Elecraft KX1

The KX1 Kit (no longer available) was the Ultra-Portable CW Transceiver Kit from Elecraft[1]. Some information about my KX1 (S/N 906) is presented.


A collection of links to Semiconductor Data Sheets may be useful for modifications of kits or for homemade projects.

Morse Code Training lists some tools and files for exercises to improve Morse Code proficiency.

Morse Code Circuits presents some circuits related to Morse Code signals.

iCW - Internet CW: iCW-at-DF7TV presents some information on my setup for iCW[9], [10].

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.

The Antenna Analyst AA-908 kit (N2APB) of the American QRP Club (AmQRP) has been completed May, 2005 and successfully applied during portable operations.

George Heron, N2APB offers some interesting kits like a DDS-60 Daughtercard for the AD9850 CMOS DDS Synthesizer at Midnight Design Solutions, LLC[3].

Dan Tayloe, N7VE has been so kind to send me a revised presentation of his NC2030 CW-transceiver[5] using the Tayloe Detector.

Douglas Hunter, VK4ADC is the author of the software GPS2Time[7] (Windows) for synchronizing a computer clock using a GPS receiver. Using GPS2Time[7] with a G-Mouse VK-162 USB GPS receiver (u-blox 7) my computer clock deviation is less than 150ms. The precision of the computer clock synchronized in that way is sufficient for most of the digital modes.

David J Taylor, GM8ARV is the author of the software NTPmonitor[8] (Windows) for comparing the time of a computer clock with a number of external time sources.


[1] Elecraft, Inc.

[2] Unofficial Guide to Elecraft K2 Modifications by Sverre Holm, LA3ZA

[3] Midnight Design Solutions, LLC.

[4] Giving Back program of the CW Academy (CW Operators' Club)

[5] Presentation of the NC2030 CW-transceiver of Dan Tayloe, N7VE

[6] Biography of DF7TV at QRZ.COM

[7] Software GPS2Time by Douglas Hunter, VK4ADC

[8] Software NTPmonitor by David J Taylor, GM8ARV

[9] iCW - Internet CW: Introduction

[10] iCW - Internet CW: Groups.Google

Thanks for your time,
73; I hope to meet you on the bands.
Tom, DF7TV, April 12, 2021.

Thomas Martin, DF7TV, Stuttgart, Germany.