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DK1IS Germany flag Germany

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Hi, nice to see you on this page!

As far as I can think back I have always been enthusiastic about radio. As a schoolboy of 14 years I became a member of the German DARC. In 1966 I got my license with the callsign DK1IS at the age of 17. From the beginning I´ve been 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 lived 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´m a retirement pensioner.

In 1999 DK1IS was the first LF station in Eastern Bavaria on 135.7 - 137.8 kHz. After moving in 2001 now I have much better possibilities to be active in that fascinating part of the spectrum. 23 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 (mostly in DFCW). Since June 2013 DK1IS is QRV on the 475 kHz MF band too. 18 countries worked on MF up to now: DL, EI, F, G, HA, HB9, I, LA, OH, OK, OM, ON, OZ, PA, S5, SM, SP, 9H1 (real CW only).

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.

Additionally access via www to a remote RX site with Perseus SDRs at our club station DL0AO (5 km away in a forest) - especially from LF to 10,1 MHz due to continually increasing local QRM level.

Antennas: Vertical helix 8 m for 7 - 30 MHz. Marconi-T, 13 m high, 33 m top load with 4 wires, 3 m wide for 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. Antennas remote selected and fed from the shack via 3 vacuum relais and 2 lines of RG 213, 25 m each. Autotransformer 50-30-12 Ohms for LF and MF. 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.

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 stuctures 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:
8 x PL519 with individual biasing, output transformer, thermo shields, air outlet holes and outlet
gaps around the tube sockets. Eurocent coins make good hubs for the plate connections.



RF compartment, bottom view, fan plate removed:
Lower middle: RF input transformer
Gray flat cable: control grid bias and cathode current sensor line for each individual tube
Upper middle: HV filter at center tap of output transformer



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 at the feed through insulator from an unlucky former spider ...



LF/MF tuner, left side:
Autotransformer 50/30/12 Ohms, RF current sensor (gray box),
fan for radial cooling of honeycomb LF coil



Back side of arbour ("tuning house"):
Antenna disconnecting and earthing switch, pulse activated via thyristors
from a capacitor 3300uF charged to 200V DC (bird´s bogle).

Hands off at switching or transmitting!



6844580 Last modified: 2015-11-10 09:31:24, 7851 bytes

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QRZ Logbook Summary for - DK1IS
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HB0/DL5YM 2015-10-05 160m CW Liechtenstein
LY8O 2015-10-05 160m CW KO24op Lithuania Remigijus Vaicius
HG6ITU 2015-10-05 80m CW Hungary Gbor Jzsa
HB0/DL5YL 2015-10-05 80m CW Liechtenstein
TA3D 2015-10-05 40m CW KM38jq Turkey Yasar GOCET
3B9FR 2015-10-05 20m CW MH10rg Rodriguez Island ROBERT FELICITE
9M2TO 2015-10-05 20m CW West Malaysia TEX IZUMO
7X3WPL 2015-10-05 20m CW JM13kt Algeria Amateur Radio Club Sahara DX

Book Totals: 313 qso's   47 confirmed Get a free logbook at QRZ.COM

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Thu Nov 26 12:24:06 2015 UTC
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