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. I am also QRV portable using simple wire antennas or from home (via iCW – Internet CW), 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.


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-ENTITIES-CONFIRMED

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

Working Awards/Certificates of CW Clubs

DF7TV - some recent awards

Morse Code (CW)

Learning the Morse Code

Logo of CWops CW Academy

The eight–weeks long Morse Code courses of CWops CW Academy[13] are characterized by clear and goal–driven roadmaps. Courses are provided at four levels — from Beginner (Limited or no prior experience with Morse Code) to Advanced (Operating 20+ wpm and desire to increase proficiency for higher–speed on–air activity). There is no cost or obligation to participate in CWops CW Academy Classes and membership is not required. Enrollment is open to anyone with the desire to learn or improve their proficiency in Morse Code.

Morse Code Training (25+ wpm)

PacmanDit by DF7TV

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

Morse Code Circuits

DF7TV: Symbol to label the side tone output socket

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

iCW – Internet CW

iCW – Internet CW

Internet CW[9], [10] allows for full duplex, QSK conversations using Morse code audio signals in Mumble[11] voice chat.

iCW at DF7TV presents some information on my setup for iCW.

CW Resources

DF7TV: Symbol to label the side tone output socket

Kurt Zoglmann, AD0WE provides a well organized overview of CW Resources[12] for learning and training of the Morse Code.

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.

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].

Frank M Doerenberg, N4SPP provides in-depth information and extensive references on the Multi Band End-Fed Antenna[4]. 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.

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 150 ms. 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.


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