Archive of my old articles

Radio technology is now more than 100 years old and this is a pretty long history. Although it should be possible to learn radio technology much faster, every good radio engineer should experience the whole story. In other words, everyone should start with the famous Tesla coil, then build something simple with vacuum tubes and germanium transistors before getting to the sophisticated semiconductors we have today.

Here I decided to publish most of my old articles for at least two reasons. First and most important, older and/or tutarial information can only be made available to young people via internet, since paper copies of magazine articles are no longer available. Second, it makes sense to study one's own history just to avoid repeating the same mistakes already made in the past.

I wrote my first article while I was 15 years old. The article was published in 1975, in the June issue of Radioamater, the official magazine of the association of radio-amateurs of Yugoslavia. The text of my article was carefully translated from Slovenian into Serbo-Croatian, the latter being understood by most people living in former Yugoslavia. Unfortunately schematics were frequently carelessly redrawn introducing errors in almost all magazines and their editors sometimes stripped out some information.

Therefore I decided to publish here my original manuscripts wherever possible. If the same article was published in more than one language, priority was given to the Slovenian version. Some information could not be retrieved, since there were no photocopiers available back in 1975. My manuscripts were initially retyped making a few copies with carbon paper. Drawings were simply redrawn if a copy was required.

Initially I did not have a radio-amateur callsign. Afterwards my articles were published under three different callsigns: first YU3UMV, then YT3MV and finally my present callsign S53MV. Since our typists only understood Slovenian, I had to neatly rewrite by hand all the manuscripts in Italian and/or English.

Since computers became available, I used in total five different printers. My first attempts were made on a big mainframe computer with the associated line printer. Then I interfaced an old mechanical teletype to my home computer. Of course the teletype used Baudot with lower-case letters only! Finally I got a real needle printer, followed by two laser printers.

Considering all these different formats, the only practical solution was to scan all the original paperwork, regardless whether it was hand written, typewriter carbon copy, mainframe printer or any of my home printers. Drawings were scanned in black-and-white while photos were scanned with gray levels. All the scanned information was finally assembled together into PDF files. At the end, a short English abstract was added to all articles in Slovenian, Italian and English.

Many of my more recent Slovenian articles, written in the timeframe 1990-2000, were assembled together in two books: Beacon 99 and Digitalni mostovi 2000. Since these two books are no longer available in printed format, I published their PDFs on my main homepage. Both books still contain useful information about weak-signal amateur radio (Beacon 99) and about our amateur packet-radio network (Digitalni mostovi 2000).

A third book on amateur satellite activities is certainly missing. There are several reasons. The most important is the total failure of the AMSAT-P3D satellite due to several independent design flaws. Free access to analog and/or digital weather-satellite images is no longer available: except for the NOAA polar orbiters, data from all other weather satellites is now being encrypted. Professional satellite point-to-point links and broadcast are being replaced by optical fiber. The only remaining satellites with free access seem to be the GPS and GLONASS navigation satellites.

The originals available were not always in the best possible condition. This is especially true for the masters for the printed-circuit boards. Before 2000 these were all analog drawings made with transferable symbols and adhesive tapes. The latter deteriorate quickly with time. Although I tried to do my best while scanning, some PCB masters may no longer be useful. PLEASE DO NOT ASK ME TO SEND YOU BETTER PCB MASTERS! I ALREADY PUBLISHED THE BEST COPY I HAD AVAILABE ANYWHERE ON MY HOMEPAGE!

Future articles are unlikely to ever appear on this list. In fact, today most of my articles are first published on the web on my homepage, since there is nothing comparable to the power of the allmighty internet search engines. Only afterwards they may get printed somewhere. On the other hand, presentations are only seldom published in conference proceedings. Therefore the web is the ideal place to publish the variuos slides in full color.

Available articles in PDF:

VHF AM-FM sprejemnik AF55 (SLO-1975)
My first published article: simple VHF receiver with very low IF, mainly for FM broadcast

Primopredajnik za CW in SSB (SLO-1976)
CW and SSB transceivers for 3.5MHz, unpublished, 2nd prize in a design competition

FM WALKIE-TALKIE (SLO-1977)
Single-channel 144MHz FM transceiver

Sprejem slik z meteoroloskih satelitov (SLO-1978)
Reception of weather-satellite images on 137MHz

FM voki-toki - nova verzija (SLO-1978)
Single-channel 144MHz FM handy-talkie

SSB-FM primopredajnik za 144MHz (SLO-1979)
SSB-FM transceiver for 144MHz with VFO & frequency counter

VHF FM sprejemnik (SLO-1980)
Wideband FM tuner, broadcast band and 130-160MHz

HRPT una nuova meta (ITA-1981)
NOAA HRPT image reception and demodulation

Preamplificatore a basso rumore per la banda S (ITA-1981)
LNA for 1.7GHz with a CFY11 GaAsFET

Convertitore per la banda S (ITA-1981)
Downconverter for 1.7GHz with half-wave, center tuned cavities

FM voki-toki za 430MHz (SLO-1981)
Single-channel 430MHz FM handy-talkie

Miniaturni 144MHz sprejemnik (SLO-1982)
Simple 144MHz SSB (DSB) receiver

Un prescaler economico per 1.4 GHz (ITA-1982)
Inexpensive 1.4GHz, divide-by-64 prescaler with the S0436 chip

APT scan converter (ITA-1982)
Weather-satellite image scan converter, TV monitor output, 128x128 resolution

RX sintetizzato per i 2m (ITA-1982)
Synthesized VHF FM receiver, 12.5kHz step, theory of charge-pump frequency-phase detectors

A digital scan-converter for weather-satellite images (ENG-1982)
Weather-satellite image scan converter, TV monitor output, 128x128 resolution

2. Frame memory PCB YU3UMV002 (ENG-1982)
New digital board for the APT scan converter, 256x256 resolution

A false-colour PAL modulator (ENG-1983)
Transforms the gray-scale output of the APT scan converter adding false colours

Transverter za 23cm u mikrostrip tehniki (SLO-1984)
Microstrip transverter 1296MHz/144MHz including VOX and antenna switching

SSB/CW primopredajnik za 144MHz (SLO-1985)
SSB/CW transceiver for 144MHz with 100Hz step synthesizer

VHF reflektometer (SLO-1985)
VHF reflectometer with stripline directional coupler

YU3UMV transverter 144/432MHz (SLO-1986)
Transverter 432MHz/144MHz including VOX and antenna switching

CW filter za 10.7MHz (SLO-1986)
CW xtal filter for the SSB/CW transceiver for 144MHz

Microstrip transverters for 23 and 13cm (ENG-1986)
Microstrip transverters 1296MHz&2304MHz/144MHz including VOX and antenna switching

A Ku-band low-noise downconverter for satellite-TV reception (ENG-1986)
LNC (feed, preamp and downconverter) for 11GHz satellite-TV reception

Satellite-television receiver indoor unit (ENG-1986)
Analog-FM satellite-TV receiver 800-1800MHz

Sprejemni konverter 29MHz (14MHz) na 145MHz (SLO-1987)
Receiver converter 29MHz(14MHz) to 144MHz

A C-band low-noise downconverter for satellite-TV reception (ENG-1987)
LNC (feed, preamp and downconverter) for 4GHz satellite-TV reception

Digital Signal Processing Techniques for Radio Amateurs (ENG-1988)
Theory of DSP filters and other circuits

Un modem FSK universale (ITA-1988)
Simple FSK modem for RTTY and packet-radio

Design of a DSP computer for radio-amateur applications (ENG-1989)
Circuit diagrams of the DSP computer

Construction and use of the DSP computer (ENG-1989)
Construction hints for the DSP computer

Amateur-radio Applications of the Fast Fourier Transoform (ENG-1990)
Theory and practical applications of FFT spectrum analyzers

Druzine TTL digitalnih integriranih vezij (SLO-1990)
Families of 74xxx TTL logic circuits

Umetni sateliti, vesoljska tehnika in radioamaterji (SLO-1990)
Satellites and amateur-radio activities

Vesoljski vremenko: (1) Polarni vremenski sateliti (SLO-1991)
Polar-orbiting weather satellites

Vesoljski vremenko: (2) Geostacionarni vremenski sateliti (SLO-1991)
Geostationary weather satellites

Amaterska sprejemna postaja za vremenske satelite (SLO-1991)
Amateur receiving station for weather satellites

Praznilec in merilnik kapacitete NiCd akumulatorjev (SLO-1991)
Automatic discharger and capacitance meter for NiCd batteries

Mosticni reflektometer 100kHz-2.5GHz (SLO-1992)
Bridge reflectometer for 100kHz-2.5GHz

Kaj bi radioamater moral vedeti o VF vodih? (SLO-1992)
Tutorial on RF transmission lines

Tranzistorski mocnostni ojacevalnik za 145MHz (SLO-1992)
Transistor power amplifier for 145MHz

Dvostopenjski predojacevalec za L podrocje (SLO-1992)
Two-stage GaAsFET LNA for L-band (1.3-1.7GHz)

Elektricni sum in elektronski izvori suma (SLO-1993)
Electrical thermal noise and electronic noise sources

Intermodulacijsko popacenje (SLO-1993)
Theory of intermodulation distortion (IMD) and practical examples

Lecher-jev vod (SLO-1993)
Lecher line as wavemeter

Sprejemnik za frekvencno podrocje 2.4GHz (SLO-1993)
Circularly-polarized feed, LNA and downconverter for 2.4GHz

Avtomat za praznicni drevescek (SLO-1993)
Three-channel Christmas-tree light show

Helij-neonski laser (SLO-1994)
Construction of HeNe lasers and simple power supply for a HeNe tube

Vijacna antena (helix) z osnim sevanjem (SLO-1994)
Theory, operation and design of end-fire helix antennas

Sestavljanje krozne polarizacije (SLO-1994)
Obtaining circular polarization from two linearly-polarized antennas

Akusto-opticni modulator za laser (SLO-1994)
Theory and design of a simple acousto-optical modulator

Popravek Kepler-jevih elementov iz meritve Dopplerjevega pojava (SLO-1994)
Correction of Keplerian orbital elements from Doppler-shift measurements

Slikovni ojacevalniki in pretvorniki (SLO-1994)
Image-intensifier tubes and image-converter tubes

Kremencevi kristali, kristalna sita in oscilatorji (SLO-1994)
Quartz crystals, crystal filters and oscillators

Sprejem APT-WEFAX slikic s satelita Meteosat (SLO-1995)
Linearly-polarized feed and downconverter for 1.7GHz

UKV FM sprejemnik za vremenske satelite (SLO-1995)
130-160MHz FM receiver with 30kHz IF filter and 5kHz-step synthesizer

Izboljsani napajalnik za helij-neonsko lasersko cev (SLO-1995)
Improved power supply for a HeNe laser tube

Johannes Kepler in Keplerjevi elementi (SLO-1995)
History about Johannes Kepler and description of the Keplerian orbital elements

PLL sintetizator za konverter za L podrocje (SLO-1995)
Synthesized LO for the 1.7GHz downconverter

Satelitsko radarsko slikanje zemeljske povrsine (SLO-1995)
Theory of satellite radar imaging

Vrste kondenzatorjev in njihova pravilna izbira (SLO-1995)
Types of capacitors and their correct selection

Mehko spajkanje v elektroniki (SLO-1995)
Soft soldering in electronics

Satelitski sprejemnik za 1.7GHz (SLO-1996)
1.7GHz receiver including data interface for NOAA HRPT

Tehnika mikrotrakastih vodov (SLO-1996)
Theory and practical (passive) microstrip circuits

5-elementna Yagi antena za 435MHz (SLO-1996)
5-element NBS Yagi for 435MHz

Vesoljski nadzornik moci z imenom LEILA (SLO-1997)
Description of the LEILA module onboard the AMSAT-P3D satellite

Piramidna lijaka za 5.7GHz in 10GHz (SLO-1998)
Pyramidal horns for 5.7GHz & 10GHz

Predelava mocnostnega ojacevalnika za 145MHz (SLO-1998)
Modification for the 145MHz power amplifier

Lastnosti in oznake keramicnih kondenzatorjev (SLO-1999)
Properties and markings of ceramic capacitors

Aktivna antenska kretnica 1.7GHz/2.4GHz (SLO-1999)
Active antenna-branching filter for 1.7GHz/2.4GHz

Kako narociti kremencev kristal? (SLO-1999)
How to order a quartz crystal

Gradnja in ozivljanje postaj z nicelno medfrekvenco (SLO-2000)
Construction and tuning hints for the ZIF-SSB transceivers

Predelave SuperVozlja in popravki TNCja (SLO-2000)
Modifications of the SuperVozelj and corrections for the megabit TNC

Amaterska izdelava tiskanih vezij (SLO-2001)
Amateur manufacturing of printed-circuit boards

Amaterski packet-radio in internet (SLO-2001)
IP over AX.25 using SLIP thorough a SLIP-KISS TNC

Rezonatorsko sito za 23cm (SLO-2001)
3-stage cavity filter for 23cm

Izboljsani PSK demodulator za 1.2Mbit/s PSK RTX
Improved BPSK demodulator for the 1.2Mbit/s packet-radio RTX

Kristalni oscilatorji in njihova zamenjava (SLO-2001)
Discrete replacement for (packaged) crystal oscillators

Installing an ATC Transponder on a Small Aircraft (ENG-2004)
ATC-transponder power budget and selection of a suitable antenna

Ne-Brezhibni protokol (SLO-2010)
A simple communications protocol, hardware & implementations

Programska oprema ATNC/EATNC inacica h91/e45 (SLO-2010)
Operation & commands of ATNC/EATNC firmware h91/e45

Available presentations in PDF:

Digitalno procesiranje signalov za radioamaterje (SLO-1988)
Practical digital (audio) signal processing for radio amateurs

DSP Using General Purpose Microprocessors (ENG-1988)
DSP modem, terminal and tracking program for the JAS-1 satellite

Experimental Reception of the UoSAT-2 2.4 GHz Beacon (ENG-1988)
Reception report and hardware block diagram

Single Frequency Refraction Correction (ENG-1991)
Ionospheric correction using delay & Doppler measurements on L1 GPS transmissions

Radio-amateur applications of GPS/GLONASS satellites:
Using GPS/GLONASS satellites as an accurate frequency/time standard (ENG-1992)
Homemade GPS/GLONASS receiver

A Satellite Receiving Front-End for 2400MHz (ENG-1994)
Antenna, preamplifier and downconverter for narrowband, weak signals

Laserske zveze (SLO-1995)
HeNe laser tube, acousto-optic modulator and image intensifier/converter tube

1.2Mbit/s SuperVozelj packet-radio node system (ENG-1995)
S5 packet-radio-network node computer (Motorola 68010), modems and radios

Uporaba novejse tehnologije za radioamaterske mikrovalovne radijske postaje (SLO-1996)
Theoretical discussion of direct-conversion and zero-IF (Weaver) SSB transceivers

23cm PSK Packet-radio TRX for 1.2Mbit/s user access (ENG-1996)
Simple Zero-IF BPSK transceiver (1W) for megabit packet-radio links

13cm PSK Transceiver for 1.2Mbit/s Packet Radio (ENG-1996)
2360MHz BPSK transceiver (0.5W) with double-conversion (75MHz/10MHz) receiver

Nacrtovanje SSB radioamaterskih radijskih postaj (SLO-1997)
Design of zero-IF SSB transceivers for 23cm and 13cm

Spektralni analizator v samogradnji (SLO-1998)
Homemade RF spectrum analyzer with tracking generator and other accesories

Razvoj visokofrekvencnega spektralnega analizatorja (SLO-1998)
Design of a RF spectrum analyzer with tracking generator and other accessories

Preklop sprejem/oddaja na UKV podrocju (SLO-1999)
Practical solutions for RX/TX antenna switching at VHF

Svetilniki Beacon 99 (SLO-1999)
Microwave radio beacons for the Beacon 99 Phare project

Izbira modulacije za packet radio (SLO-2000)
Theoretical discussion about different modulation formats in packet radio

A simple TNC for megabit packet-radio links (ENG-2000)
Fast KISS TNC with 68HC000 CPU and Z8530 SCC generating vectored interrupts

Conjugated-Phase Antenna/Transponder (ENG-2001)
A proposal for a satellite antenna/transponder self-focussing array

An improved BPSK demodulator for the 1.2Mbit/s packet-radio RTX (ENG-2001)
BPSK demodulator performance and different Costas-loop designs

Tehnika za frekvence nad 20GHz (SLO-2002)
Semiconductors and techniques for frequencies beyond 20GHz

Radijske komunikacije v letalstvu (SLO-2003)
Radio communications and radio-navigation aids in aviation

Sodobni VF/mikrovalovni tranzistorji (SLO-2004)
Theory about modern RF/microwave (power) transistors

Intermodulacijska popacenja ojacevalnikov (SLO-2006)
Intermodulation distortion in RF amplifiers

Pristajalni radarski visinomer za mala letala (SLO-2006)
Landing radar altimeter for small aircraft

Toplotni sum v radijskih zvezah (SLO-2007)
Thermal noise in radio communications

Konstrukcija frekvencmetra (SLO-2008)
Design of a frequency counter

Letalski radarski visinomer (SLO-2008)
Aviation radar altimeter & vertical navigation radar

Optical-fiber time-transfer & synchronization systems: advantages, physical limitations and practical implementations (ENG-2009)
High-accuracy clock distribution over compensated optical fiber

ESMO RADAR proposal (ENG-2009)
A RADAR payload proposal for the European Student Moon Orbiter

Kratka zgodovina nasih poskusov z umetnimi sateliti (SLO-2009)
Short history of our experiments with artificial satellites

DDS VF izvor (SLO-2010)
A simple DDS RF signal generator with AM, FM and other modulations

Ne-Brezhibni Protokol (SLO-2010)
A simple communications protocol for lossy radio channels

Ne-Brezhibni Protokol (2) (SLO-2010)
A simple communications protocol & hardware for lossy radio channels

Nadgradnja omrezja za Ne-Brezhibni protokol (SLO-2011)
Network upgrade and other developements of the NBP

Megabitna BPSK radijska postaja za 430-440MHz (SLO-2011)
An 1.2Mbps BPSK radio transceiver for 430-440MHz

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