ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: l-assoc
DK1IS Germany flag Germany

Login is required for additional detail.


Email: Login required to view

Ham Member Lookups: 14151


Hi, nice to see you on this page!

As far as I can think back I have always been enthusiastic about radio. Born in Hamburg at the end of 1948, as a schoolboy aged fourteen I became a member of the German DARC. In 1966 I got my license with the callsign DK1IS at the age of seventeen. From the beginning I was QRV mostly in CW on the HF bands with the usual periods of reduced activity due to study, job and family. I´m married and we have two grown sons. Since 1981 we have been living in Amberg, a town in Eastern Bavaria, about 60 km east of Nuremberg. After 17 years of working in the electrical industry I changed to the newly Amberg University of Applied Sciences in 1998 as a Professor of Electrical Engineering. Since 1999 I have been the dean of our faculty and since 2011 I´ve been a pensioner.

In 1999 DK1IS was the first LF station in Eastern Bavaria on 135.7 - 137.8 kHz. 24 countries worked on LF up to now: DL, F, G, GI, GM, HA, HB9, I, LX, OE, OH, OK, OM, ON, PA, S5, SM, SP, SV, RA6, UW8, YU, Z3, 9A3 (mostly in DFCW). Since June 2013 DK1IS has been QRV on the 472 kHz MF band too. 20 countries worked on MF up to now: DL, EI, F, G, GM, HA, HB9, I, LA, OH, OK, OM, ON, OZ, PA, S5, SM, SP, YO, 9H1 (real CW only). More information about this MF band see http://www.472khz.org/  Since January 2018 DK1IS has been also QRV on VLF 8.27 kHz - a new and challenging mission! First tests with plain carrier have been recorded in DL, G, I, SP.

Rig here:

HF: Kenwood TS-950SD, controlled by external GPS standard; Kenwood TS-50S (powered by solar cells plus accu).

LF, MF: Receiver RX1001, Exciter EX1001, both from Hagenuk, optionally controlled by external rubidium frequency standard from Rohde & Schwarz. Exciter running at 13.6 MHz respectively 4.73 MHz followed by a frequency divider for 1-Hz-steps on LF and 10-Hz-steps on MF. Homemade tube PA 2 x 4 x PL519 push pull class B, broadband transformer coupled, max. 800 W RF on LF and MF, plate efficiency 73% at 600 V DC. QRV in CW, QRSS, DFCW. Alternative exciter (most commonly used now): Frequency synthesizer MG 100 M from Schomandl, 0.1-Hz-steps for CW and DFCW up to 100 MHz, optionally controlled by external rubidium frequency standard too.

VLF: Reception via remote RX site at our club station DL0AO, data transfer via www. Exciters for plain carrier: synthesizers MG 100 M or ND 60 M from Schomandl, controlled by external rubidium frequency standard. Later on a special VLF software SpectrumLab will be used to generate more complex signals from the PC, GPS controlled. Audio PA 2 x 300 W, only one channel used.

Additionally access via www to a remote RX site with Perseus SDRs and a lot of different antennas at our club station DL0AO too (about 6 km away in a forest) - especially from LF to 10,1 MHz due to continually increasing local noise level. Since June 2016 there has been one more remote controlled SDR RX site on my garage, about 100 m away from my home and fed by a solar system, no utility mains. Selectable RX antennas there: active rod, earth dipole 42 m with four remote controlled grounding configurations and a rectangular horizontal loop 11 sqm right on the garage roof. Noise level up to 30 dB better than at home. Data transfer via a private 5-GHz-Ethernet-link. A kind of audio diversity by fast manual changing between the available receivers and their antennas often results in superb improvements of signal readability during tough conditions.

Main antenna: Marconi-T, 13 m high, 33 m top load with 4 wires, 3 m wide for VLF, LF, MF and HF (on HF you rather may call it inverted ground plane), C = 660 pF, R = 30 Ohms, measured at 136 kHz respectively 12 Ohms at 473 kHz and 160 Ohms at 8.27 kHz. Autotransformer 50-30-12 Ohms for LF and MF. HF spare antenna with different radiation pattern and less efficiency: Vertical helix 8 m. Antennas remote selected and fed from the shack via 3 vacuum relais and 2 lines of RG 213, 25 m each. Additional active rod HE-011 from Rohde & Schwarz for reception.

Couplers: Harris RF-615B in the arbour ("tuning house") for HF. MF: remote controlled (by barbecue grill motor) Hagenuk-MF-variometer tuner 120 - 550 uH in the arbour plus additional homemade honeycomb loading coil for LF, L = 1.75 mH, Q = 540 with forced radial air cooling for long key down periods. Antenna current 5 A, antenna voltage 8.9 kV rms measured at 136 kHz, 750 W. VLF: first matching transformer 8 to 50 Ohms in the shack, a second one 50 to 300 ... 450 Ohms at the arbour. Loading coil with 60 ferrite inductors 10 mH / 600 mA rms in 4 ring-shaped layers, variation range by tappings and variable mutual coupling 10 ... 700 mH . Additional variometer 7 ... 14 mH for fine tuning. Antenna voltage 18 kV rms at 8.27 kHz and 600 mA antenna current. Systems bandwidth without re-tuning: 180 Hz at -3dB.

Ground: 3 bare copper wires 6 m, buried 20 cm below the lawn with ground rods 1 m at each end + 2 ground rods 3 m + mains ground + water pipe system + all metal structures at the terrace side of the house.

Vy 73 es hpe to cuagn on the air!

Tom, DK1IS


Here are some pictures of my LF/MF station:


LF/MF Rack:
PA, PA power supply, RX1001, EX1001



PA, top view:
Vf/-Vg1/+Vg3 transformer, mains & TR contactors, RF compartment. Thermal management by
pressurised chassis, air outlet holes and thermo shields, transferring thermal radiation to convection.



RF compartment:
2 x 4 x PL519 in push-pull with individual biasing, resulting in a plate dissipation of 180 W and a
transconductance of 180 mA/V per side. Output transformer, thermo shields, air outlet holes and
outlet gaps around the tube sockets. Eurocent coins make good hubs for the plate connections.



Power supply:
Vp 600V 2A DC, Vg2 180V 0.6A DC. Starter electronic due to inrush and charging currents.



LF/MF tuner in the arbour:
Variometer remote control (barbecue grill motor)



LF/MF tuner:
Variometer, radial cooled honeycomb LF coil, vacuum relais LF/MF/HF

Brown smoke residue at the feed-through insulator from an unlucky former spider ...


Back side of arbour, antenna switch box:
Upper middle: Antenna disconnecting and earthing switch, pulse activated via thyristors
Bottom: VLF components. Left: loading coil
10 ... 700 mH, 18 kV rms at 8.27 kHz / 600 mA
Right: Variometer 7 ... 14 mH, rms current meter, matching transformer

Hands off at switching or transmitting!


                    Marconi´s end on a frosty winter morning:                  



Always 10 years older than me, still walking strong:
German 2-v-1 RX Torn. E. b/24b "Berta" from 1938, 96.6 - 7095 kHz
I was lucky to get it from a ham buddy in 1964

8625562 Last modified: 2018-02-03 21:08:47, 9864 bytes

Login Required

Login is required for additional detail.

You must be logged in to file a report on this page

Please login now...

QRZ Logbook Summary for - DK1IS
Latest Contacts for DK1IS at QRZ.com
dedateband mode grid Country op
OK2BPU 2018-02-18 160m CW JN89nj Czech Republic EMIL ZUKAL
OE6DY 2018-02-18 160m CW Austria ING. HEINZ DIRSCHLMAYR
F8AIL 2018-02-16 40m CW France
DK8ND 2018-01-13 630m CW JN48qq Germany Hans-Albrecht Haffa
OK2BPU 2018-01-04 160m CW JN89nj Czech Republic EMIL ZUKAL
UA5C 2018-01-04 160m CW KO85to Russia Alexandr N. Gimanov
G4DJX 2018-01-02 60m CW IO91vl England ALAN GRAY
9A4MF 2017-12-01 80m CW JN85oj Croatia MIRO Miroslav Fila
S57Z 2017-12-01 80m CW JN76fc Slovenia Igor Didovic
ZA1WW 2017-12-01 30m CW Albania KOSOVO ALBANIA
LZ307MU 2017-11-30 40m CW Bulgaria Bulgarian Club Blagovestnik
DF7DC 2017-11-23 60m CW JO40IC45 Germany Hans Steinzen
BD4WN 2017-11-22 80m CW OM92lb China Yang Bin
LY2NK 2017-11-22 160m CW Lithuania Algis Kregzde
PE1MBR 2017-11-22 60m CW JO22qe Netherlands Dick Radstaak

Book Totals: 767 qso's   116 confirmed Get a free logbook at QRZ.COM

World Continents Award#14098
Granted: 2016-06-12 19:58:01   (DK1IS)

  • 20 Meters Mixed
  • Mixed CW
ad: giga-db
Copyright © 2018 by QRZ.COM
Tue Feb 20 21:04:03 2018 UTC
CPU: 0.054 sec 80845 bytes mp