Back on air since August 2011. Currently using:
rig: IC-756 PRO-III - 100W barefoot+
SDR: Funcube Dongle Pro+ with CW Skimmer and RBN upload: http://www.reversebeacon.net/dxsd1/dxsd1.php?f=0&c=vk3ffb&t=de
10m: cubical quad
20m - 80m: 80m delta loop with balanced feeder & symmetrical PI matching unit For details see schematic below.
QSL Cards: Presently no paper QSL cards. Only eQSL possible
My interest in radio was triggered by my high-school science & math teacher. First Rx was a 0-V-1 with the ECL80 tube. With this I discovered the world of ham radio. My first on air ham radio teachers were Arno, DL9AH and Mario, DJ7UA and many others I used to listen to. SWL-ing was another domain that interested me a lot during my early radio years.
In 1982 I re-discovered the magnetic loop antenna for ham-radio and published an article, together with ham friends (cq-dl 9/82 p. 435). This paper found strong interest and caused a loop building avalanche among hams in Europe and commercial versions appeared soon thereafter.
By profession I am a microwave r&d engineer specialised in filter design and general passive microwave component design. Presently, I am engaged in high-power broadcast filter design from a few 100 watts to over 20kW, mainly in the UHF TV band. I hold a number of patents, have published papers and since February 2012 I am a Bell Labs DMTS member.
Former callsigns: DF3IK, VU2DPG
CW Skimmer and Reversebeacon
Link to my RBN spots: http://www.reversebeacon.net/dxsd1/dxsd1.php?f=0&c=vk3ffb&t=d
See what I do with the skimmer data below. My main interest is in 10m beacon spotting with an SDR Rx. The SDR processes the entire 10m cw beacon band, decodes and uploads to the RBN website. Short video of cw skimmer screen: http://youtu.be/_5tLutjRtCc
Compare the time lines. Clear coincidence and 2nd peak in signal level graph is also confirmed as a second flare with lower intensity and with different time response. For more info on Spectography.
Note the solar panels: total output 4.4 kW (23 panels total). Yes,my station is poweredby the sun !My power bills show credits only. Thanks to my German SMA inverter,there is no radio noise.
The dish on the right side is a C-band SAT TV dish for watching German TV here in Australia.
An evening view from the 80m delta loop feedpoint to the east
south-eastern corner of 80m horizontal delta loop
Balanced Feeder 'Tuned Antenna System'
Below is a schematic of my balanced feeder antenna arrangement using a symmetrical PI-network and a 1:1 balun. This is not my invention, but I like it's simplicity and versatility. For symmetry reasons it is important that both roller inductors are always set to the same inductance value. Thanks to VK3QD and VK3ATC who helped me re-discover the tuned antenna system.
The idea of this arrangement is this: The LC tuner network 'tunes' the antenna and transforms its impedance down to balanced 50 Ohms real. The 1:1 balun then only transforms from a balanced 50Ohms impedance to 50 Ohms unbalanced (coax). It is important to understand, that the balun is running between two real impedances. This is very different from having a balun on the antenna side of an unbalanced tuner, where the impedances are not real. Complex impedances can have extreme values and ferrite core baluns are not usually designed to handle these. (Oops, the variable L's in the circuit below are actually Lmax=15uH)
This is probably the coolest link between ham radio and the internet. When I heard about it, I immediately became a regular user. In short: A global network of amateur cw receiving stations, called 'skimmers' feed their decoded reception data including callsign, signal-to-noise ratio and cw speed to a global server: www.reversebeacon.net. I use it to find out 'where has my cq call been heard ?' So, in practice, you give one or more cq calls on your band of interest and then jump on the internet to see where you have been 'heard' (use the dx spot search feature and type in your own callsign). After doing that, you have a pretty good idea about current propagation conditions and depending on that you may want to give a few more cq calls :)
Check my CW Skimmer: http://www.reversebeacon.net/dxsd1/dxsd1.php?f=0&c=vk3ffb&t=de
VOACAP Online - by OH6BG
Another true 'northern light'! Now we can use professional HF propagation prediction online. Find out whether propagation is likely to exist between two places and what frequency to use. An invaluable tool for the serious DXer: http://www.voacap.com/prediction.html
Carl has a lot of good info on HF & VHF propagation:http://k9la.us/index.html
Here comes Venus. Improvised setup with a simple telescope and a sheet of white paper & iPhone camera. You can
even see some sunspots ! :
Recent S-meter recording of W5OM 10m Beacon using the fine S-meter Lite software:
Last modified: 2014-04-12 22:10:25, 11255 bytes
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