January 6, 2002 18:15

The SM0WXV Radio Playground

Claus,Järfälla/Sweden JO89VL
member SSA, AMSAT-SM

Updated: January 6, 2002 Rev.:R1B

To be completed and improved...



This page is (hopefully not) another contribution to the "Worlds Most Useless Webpages Competition". Its intention is just to supply some impressions and links regarding ham radio and radio related issues. Some hams may find inspiration here, experts may feel free to have a good laugh.Those links have been very helpful for my own little projects . Moreover it´s also an html playground for me just to learn a litte bit more about this as well...
I´m living close to the north-western part of Stockholm and moved from Germany to Sweden in 1998. My german call is DF5EH. I like playing around with such things as for instance WX-satellite reception,VHF-Aurora operation, CW on shortwave and VHF/UHF also SSB, and, but less intensive PSK31, SSTV,RTTY,AO40 and other satellites, different types of antennas and so on. Nowadays a lot of interesting ham-radio shareware and freeware programs are available which are worth spending some time with.
Radio experiments must not be expensive. Reassembling surplus-PC´s, converting an old stereo for weather satellite reception or building effective antennas using cable-rests is sometimes more fun than buying new equipment.....

AURORA, "the poor man´s EME" Living in this area of the world opens many opportunities to try Auroras on VHF. With at about 10W (maybe less, better more) and a 6 to 10dB directional antenna you already can make VHF radio contacts about 500 to 1000km and sometimes even more. I built a simple 4 element quad antenna out of thin bamboo sticks from the garden shop, a wooden lath and some coax-cable rests which gives me say at about 8dBd. If you are wondering about the design, i picked up a shortwave 4 element quad from the famous Rothammel antenna book and recalculated it for 144MHz. Not an optimized hightech antenna but it turned out to work fine....Put onto a 3m pole and slightly elevated directed to 330 degrees, it made it possible to work LA, LY, ES, OH, OZ, DL, and stations in northern and southern Sweden from this location. It´s quite useful to watch VHF-beacons but also the spaceweather and OH2AQ DX-Summit-links below give you useful information about possible openings which appear depending on the solar activity 10 to 50 times a year, lasting from some minutes to several hours.Unfortunately they occur also when you´ve got to work or to sleep.... Aurora operation is one of the "modes" that work preferably best on CW, during strong openings even SSB works, it sounds like a very strange whispering. I myself spent many interesting hours watching radio auroras. Also visual auroras, the northern lights, are unforgettable events. How to find out that an Aurora is coming up? Well, the first thing is to monitor the sun on the spaceweather page. If a strong flare appears (M or X level), check whether it is earth-directed or not.(A strong ongoing earth directed flare will also often cause an "immediate" radio-blackout on the earths sunside, for instance on shortwave. But this is not an aurora yet.) The particle stream will reach the earth after half a day up to 2 days later , the tables and graphs on the spaceweather page will show its speed and density. The main thing to watch then is the direction of the interplanetary magnetic field in the related window. When it starts tilting south, a geomagnetic storm and also an aurora can be expected. Also coronal holes can be the reason for solar windstreams causing auroras. Watch the beacon band and the CW part of the 2m-band and of coarse the sky on clear evenings for visible AU´s....I experienced it only twice, but when a visible aurora appears, it does not seem to work on radio, maybe this is because my position then was below the reflecting "curtain"..... 6m-band is another good and fascinating alternative for aurora operation, 70cm and 23cm reflections are very weak.
Curious? Well have a look,...try it yourself!......

Where am I?
A good question. I´ve been looking for a good SW to calculate positions,locators and distances in both ways (lat/long or locator) and finally found this nice VB program written by ON1KVE, available with and without VB6 Runtime files. A good discription of the so called "Maidenhead-locator-system" is given by by Jon, SM3OJR


Weather satellite reception
Due to the fact that good software is available, the only thing i had to worry about was how to get a suitable receiver and antenna. For instance a scanner would do it in case it provides FM-wide mode. I decided to "wreck" an old analogue car-radio by changing the variometer-coils and the capacitors in the oscillator and preselector circuits. This made the radio unusable for its former purpose and moreover it was only working in a small range around 137.5 MHz but at least there it worked. The next victim was an old home-stereo receiver due to the fact that it had such features as field-strength and center tuning indication and memory buttons, i mistreated it in a similar way and this also worked. The sensitivity was not too good so i had to add an antenna preamplifier, modified an old dualgate-mosfet preamp i built for 144 MHz some years ago. A very good antenna was published in the swedish QTC-magazine and also by Jerry, K5OE. The picture shows my ugly "prototype". The body is made of PVC-water pipes and the active parts are coax- rests. Today i´m using a similar construction with reflector under the roof. It allows to receive the NOAA and Meteor satellites with a good coverage from southern Germany to northern Sweden. For instance the NOAA-satellites will provide at least two 45 degrees to overhead passes per day. Those of you using directional circular polarized antennas will be able to get weather pictures from northern Africa to Greenland.

PSK 31 , an direct A to B digital narrowband mode which maybe will not replace CW but works as excellent on shortwave. Even for people who not really love packet radio and other digital modes with its nodes and TNC, PSK31 is a very attractive alternative. It unites the advantages of CW ( very low occupied bandwidth,suitable for QRP) with state of the art error correction and high user comfort and low TVI risk. Surely it´s not a simple technique even in case it looks that way. It starts with the fact that you´ll need a computer in the shack.......The DSP part is done by the soundcard and PC, such as the viterbi decoding. Finally, if fading and QRM occurs also PSK31 will come to its limits as CW does. It´s not meant for file transfer but offers a really good typewriter speed. For more stable radio channel conditions (no QRM and QSB and quite strong signals) a QPSK version with better error correction is available. I myself started off with some reception experiments on 80, 40 and 20 meters and was very surprised how fine it works. For instance the DIGIPAN program (among others) allows to listen to two stations at the same time. My old P1 133 MHz PC with 40MB RAM works without problems in this mode, probably even a 486 will do. This is a brilliant mode for people with bad antenna conditions and/or QRP like me, also a very silent one without any beeping in the shack, if desired. Even from the TVI point of view it seems to be less "harmful" than on-off keying and SSB.

Meteorscatter
I haven´t got any deeper experiences with this, except hearing some pings or a longer burst accidentally when tuning over the 2m band or even on FM-radio channels during a meteor shower. Predictions can also be found on the spaceweather page.I also tried the WSJT-SW by K1JT and could decode a calling MS-station from the neighbourhood. This type of 4 FSK weak-signal communication requires exactly matching frequency settings at both sides and allows to exchange short messages .A good manual is available on K1JT´s page. Another fine thing about all this is, that even meteor showers, similar to auroras can be seen on the dark and clear sky and due to that fact that i´m a dreamer you can imagine i already saw a lot of shooting stars...Howewer, if you want to learn more about all this try for instance the DK3XT or the G0ISWVHF DX-link.

RTTY,SSTV
Do you remember the "good old times" building filter-circuits with 741 opamps, dragging home heavy , oily and noisy teletypers or assembling flying spot scanners or scopes with 2" "long glowing" CRTs and all this magic stuff? Well, i really don´t know whether the times became better but to run SSTV (of coarse in colour) or RTTY with fantastic filtering, saving tools and much more pretty details has become really easy. If you´re not a programmer yourself you´ll maybe missing the peripheral work to do and moreover the technical perfection of today makes all these things less exciting. On the other hand, if you are only concentrating on the results on the bands or want to run SSTV or RTTY just for fun from time to time, MMSSTV and MMRTTY is the right thing for you. Other programs are available and surely perform as good but up to now i mainly tried the ones mentioned before and enjoyed it.

TOYS....
Well,the following picture gives just a short glance about my modest radio equipment. For shortwave i´m using an ALINCO DX-77, all WARC, 100W TRX and an old Heathkit HW9 (8band), i once assembled. The only currently available antenna is a 15m piece of wire, mounted as a sloper in an old oak tree. The VHF-rig is a Kenwood TS-700S (all-mode, 10W) which is still going strong, antenna for this is the 4 element quad mentioned above, another setup with rotor, M2 beam and a flexa-Yagi for 70cm is "under construction". 70cm is done by an ICOM IC 402 SSB/CW transceiver (3W) and a 15W linear.The old stereo receiver (left side of the picture) is converted for WX-satellite reception. Moreover i´m using surplus-PC´s in the P1 133 to 166MHz class. Some more "loose equipment" is available for future purposes.



Below you´ll find some links to start your own experiments


Propagation links:
OH2AQ DX-SUMMITongoing Ham activities
SPACEWEATHERsolar activities
G0ISWBeacons, propagation, Aurora spots,MS and more...
Satellite tracking and satellite picture processing
WXSAT,WXTRACK... Excellent tracking and weather satellite reception program SW by David Taylor
Remote Imaging Group Lots of information and links regarding WX-satellites and more
NOAA NOAA WX-satellite APT related documents
PA0ROJ Antenna... About Helical quads, in dutch, see the drawings!
QRA-locator links
Where are we? by Jon, SM3OJR
ON7VZ homepage (VB) download QRA-loc program by ON1KVE
Antennas for satellite operation and more...
K5OE´s antennas fantastic antenna projects by Jerry,K5OE
PSK 31 information and downloads:
PSK31Info about PSK31
DIGIPANHere you can download the SW
RTTY and SSTV
MMSSTV,MMRTTY etc.
Ham Radio Equipment photographs and manuals etc.
RIGPIX by Janne, SM0OFV

Meteorscatter and WSJT...
DK3XT Meteorscatter and more....
WSJT K1JT WSJT homepage
QRP and homebrew/misc.
JF1OZLinteresting,exotic and plentiful, don´t care about tanks and planes, if you dislike it....
Organisazional links
SSA (Swedish ham-radio organisazion)
AMSAT-SM (Swedish ham-radio satellite organisazion)
DARC (German ham-radio organisazion)
AMSAT-DL (German AMSAT, good AO40 info)
RAC Canadian Radio Club index, many interesting links
Tillbehör
www.elektrondata.se webconter om du bor i Sverige, här finns det en bra webbräknare att hämta....Tack för det!
GOOGLE my favorite search engine
Gör en egen hemsida Lättpocket, pagina förlaget
aspire HTML-editor SW
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