I was born in 1964 and I've got my license in 1997.
My first call was DG4ACC. In 1998 I extended the license to class B with complete access to all legal amateur radio
bands and outputs and got my new call DJ1WF.
My activity in amateur radio decreased rapidly after my son was born in 1999 and I built a small house in 2000 for my
family and myself.
After the new QTH was finished and the son became older I began setting up my shack.
. . . and. . . of course. . . my antenna .
My main activity in amateur radio is ATV. Corresponding to my favorite mode, I use my shack mostly to develop and
build technical equipment for ATV such as baseband units, TXes, RXes and so on. A very special favourite of mine i
s to develop, build and run equipment for ATV-transmissions via laserbeam.
One result of these laser-activities is the very first optical input in the THz-range on a ATV repeater in the whole world.
Now there are some other ATV repeaters with an optical input, but DB0TVH was the first one ever.
For details, please have a look at http://dj1wf.darc.de (German language)
In 2007 Tom, DL9OBD and myself performed the long distance record for ATV-transmissions via laser. We sent a
color ATV signal via laser over a distance of 83,3km. We know there are other and longer distances transmitted via
laser, but they all made narrowband transmissions, no ATV. An ATV signal is a broadband signal und needs much
higher signal levels than CW for example. So it is much easier to get a narrowband connection via laser than a
broadband one. The ATV signal quality over the 83,3km distance was quite good, so we expect much longer distances. In 2013, we improved the maximum Laser-ATV distance up to 118,4km ( http://dj1wf.darc.de/Laser/Brocken/Brocken.html ) .
Depending on the activities on higher frequencies, my activities in shortwave are poor.
But I like to use mobile equipment mostly on 40m during longer travels by car.
It is not so often, but sometimes my QRL sends me some miles away from home.
In such a case I take my Icom IC735 and fix it on my car's dashboard. My Antenna is an Outback1899, antenna length 1,70m.
100W output combined with this short antenna is normally enough for fine QSOs through Europe.
During good conditions, I also worked an American station on 40m with my mobile Equipment on the way to QRL in
the morning, and I cracked a pile up to GB2HI on Hilbre Island during my way back home on the motorway A7
somewhere between Kassel and Goettingen in Germany. And, in Summer 2012 I had a fine 40m-QSO from my
mobile station with a very nice OM from Brasil during my holiday time. More than 10000 km with only 100W and
1,7m antenna length on 40m with 5/7 report was very amazing.
Beside my mobile activities on shortwave, I also use mobile equipment for ATV, too. The ATV TRX and the antennas
are completely homemade.
The car is a leased one by QRL, so I am not allowed to install equipment or antennas permanently. The only way to
fix all the antennas is to use magnetic antenna mounts.
The following picture shows my mobile antenna farm .
The next picture shows my ATV TRX. It was built in 1997 and modified several times. This TRX was used for ATV
transmissions from a hot air ballon, from a flying helicopter, from several portable activities and . . . until today. . .
for mobile ATV. The housing suffered from all these activities, but the inner circuits still work well.
I also love to be QRV from different holiday locations. With my Icom 735 and 706, a battery and a piece of wire thrown in the trees matched with a manual tuner I made lots of nice QSOs.
Another hobby is to develop and build equipment for VLF-reception (the very loooooong waves) in the range from3kHz-150kHz. The main results are a very simple VLF converter which only needs a 30cm telescopic rod antenna for fine results and a VLF pocket receiver. The pocket receiver was published at the "holy bible of VLF enthusiasts",
In January of 2016, I was allowed to use a thermal imaging camera from my QRL for some interesting examinations. The following photo shows thermal images from an Outback 1899 mobile HF multiband antenna after 2 minutes continuous transmission with 100 Watts. The poor efficiency becomes visible, the coil heats up extremely and only a few Watts are radiated. It is also interesting to see the 70cm TRXes rod antenna also warms up by the RF signal even if only 5 Watts are used.
. . . to be continued . . .
7138978 Last modified: 2016-03-04 22:14:12, 6015 bytes
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