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Électronique et

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À propos de VE2AZX

             

Jacques  Audet   VE2AZX

 

Electronics and

Amateur Radio

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About VE2AZX

 Notre site de VOYAGES

Documents en français       Equipments et pièces à vendre      SERVICES  TECHNIQUES

Présentation sur les Baluns et Ferrites   Pourquoi utiliser un balun - Types de Baluns: courant et voltage - Comment les vérifier - Vérifiez votre balun et vos ferrites avec votre analyseur SWR.  Utilisations de ferrites sur le feeder et sur les conducteurs environnants.  Et plus encore ...

Quiz sur les antennes et lignes de transmission   Concepts de base, paramètres des lignes de transmission - Mesure de l'impédance - Utilisation d'un analyseur SWR - Pourquoi un câble coaxial ayant un conducteur central #12 a-t-il plus plus de pertes qu’une ligne parallèle utilisant un conducteur #16 ? - Combien y a-t-il de conducteurs indépendants pour le RF dans un câble coaxial ?  Qu’est-ce qu’un antenna tuner ? - La puissance réfléchie vers le TX par l’antenne est-elle de la puissance perdue ?  Un SWR élevé dans une ligne balancée ne causera pas de radiation à partir de la ligne…, vrai ou faux ?   Un faible taux d'onde stationnaire est la preuve qu'un système d'antenne fonctionne bien et est efficace, vrai ou faux ?  Et plus encore ...

Schéma de la sonde courant MFJ-206   Cette sonde permet de mesurer facilement les courants circulant sur le blindage du câble coaxial et sur les conducteurs de l'antenne.

Antenne verticale portative 75 - 40 mètres  Cette antenne possède une bonne efficacité et est facile à monter/démonter. Hauteur: 28 pi.  Utilise 3 radiales surélevées.

Utilisation de STUBS coaxiaux pour atténuer les signaux provenant d'autres bandes  Techniques utiles en HF durant le field day !

Shunts Fabriqués avec des Conducteurs Standard   Utilisez les câbles d'alimentation pour mesurer le courant.

Variac et Wattmètre 60 Hz - Voltmètre - Ampèremètre   Lectures numériques et monitoring des formes d'onde du voltage et du courant sur un oscilloscope.

Variac et Wattmètre 60 Hz - Schéma

 

English Documents            Equipments and Parts for Sale

Baluns and Ferrites

Baluns and Ferrites Presentation   Reasons for using a balun - Balun types - How to check your balun an ferrites with a SWR analyzer - Using ferrites on your feeder and nearby conductors and more ...

Common-Mode Chokes by Chuck  W1HIS   This complements my document on baluns and ferrites.

Check your Ferrites with your SWR Analyzer   Describe an easy to build fixture that allows you to verify the effective impedance of ferrite cores.

MFJ-206 Current  Probe  Schematic    This magnetic probe allows quick relative measurements of RF currents on the outer shield of a coax cable and antenna elements.

Amidon Ferrites - Inductance and # Turns Calculator   Excel spreadsheet calculates the low frequency inductance and # turns for Amidon parts.

Transmission Line Stuff - Q Factor

Measure Cable Zo with an SWR Analyzer  A simple technique that allows measuring cable Zo from 50 up to about 100 ohms

Coaxial Cable Delay - Theory   Why is the delay changing over frequency ?

Coaxial Cable Delay Measurements   Reports on delay measurements show that coaxial cables are not all the same.

QEX Article Sept/Oct 2006:  Q Calculations of L-C Circuits and Transmission Lines: A Unified Approach   Calculate the Q factor of any circuit based on its complex impedance data. These computations allow easy simulation and optimization of stub resonators. They apply to RLC circuits, transmission lines and antennas.

Get the Files Related to the above QEX Article (Select 9x06 Audet.zip)   From the ARRL  web site.

Calculates Losses, Dielectric Loss Tangent, Q factor for short lines  For lines which are less than 1/20 wavelength, it's easy to compute loss parameters. An Excel spreadshet does the computations.

Calculate the Equivalent Q Factor of Cascaded Resonators  Applies to a pair of resonators on the same frequency.  Excel spreadsheet.

Q Factor Measurement with an SWR Meter  The author reviews existing techniques and proposes a simpler method that uses an SWR analyzer along with a spreadsheet that easily computes the unloaded Q.  To be published in QEX.

Coaxial Cable Currents  In this paper I analyze and measure coaxial lines when subjected to currents on the outer shield. The analysis may be done with simple models, no black magic being necessary. A lab grade VNA is used to precisely measure SWR and attenuation.

Use 75 ohm Hardline in a 50 ohm System   Describes how to build L-C transformers at both ends of the line.

Make your Own Custom Impedance Coax   Shows how to make 125 ohm coax for use in quarter wave matching of folded dipoles au VHF.

Frequency Standards - Measurements

Off the Air Frequency Measurements FMT

Modifications and Analysis of VE2ZAZ Frequency  Standard

HP 10544A  OCXO as used in HP 5328 Counter, Data Sheet and Schematic

My new 10 MHz GPS Frequency Standard using an MV89A OCXO and Clock Distribution

Connie K5CM  FMT  web site

Clock Stability Testing  Stability comparisons of 10 MHz clocks: HP 10544A - HP 8924C – MV89A - HP 10811A - SMHU sig gen.  Measurements are short term stability, with readings every second.

Filter / Duplexer Stuff

Theory and Testing of Duplexers  What you always wanted to know about duplexers.

 

Coupling Loops for Duplexers  Shows the influence of different loop shapes on the insertion loss.

Narrow Band Crystal Notcher  A Simple Circuit for making phase noise measurements.

HP 5253 Frequency Converter makes a High Q VHF Bandpass Filter  Tunes 50 to 500 MHz, easy to modify.

HP 5254 Frequency Converter makes a High Q UHF Bandpass Filter and Harmonic Generator   Tunes 300 to 3000 MHz, easy to modify.  Low noise harmonic generator.

R-L-C Circuits and Crystals Measurements

Measure and Calculate the Q and Bandwidth of R L C   Series/Parallel Resonant Circuits with only 3 Attenuation Measurements  Excel spreadsheet.

Measure and Calculate Crystal Parameters with 3 Attenuation Measurements.  Similar to above Excel Spreadsheet.  Allows VNA attenuation data (S21) to be used.  Shows the shunt type fixture that I use.

S11 Data Converter  Excel Spreadshet converts complex reflection coefficient data to Return Loss, Real and Imaginary components and equivalent L or C values. Also provides plots.

OTHER

60 Hz Line Voltage Limiter uses a GFI (Ground Fault Interrupter)  Basic article published in Electronic Design, June 2011.  Prevent long duration line overvoltages from damaging your equipment.  Note that varistors as used in common surge protection devices can only suppress short duration voltage transients.

Line Voltage Limiter - Additional Info

Variac and 60 Hz Wattmeter - Voltmeter - Ammeter   Provides digital readings and allows monitoring voltage and current waveforms on a scope.

Variac and 60 Hz Wattmeter - Voltmeter - Ammeter - Schematic

Easily Made Current Shunts Using Existing Conductors  Use your equipment cables as current shunts.

Repair of HP Programmable attenuators (from Lothar Baier and myself)

HP 8753D  VNA   Save Waveforms and Measured Data - The easy way

Noise Figure testing  Excel Spreadsheet.  Use your spectrum analyzer or suitable amplifiers/detector to measure noise figure.  Based on  Agilent Application Note 57-2 -  Noise Figure Measurement Accuracy – The Y-Factor Method    http://cp.literature.agilent.com/litweb/pdf/5952-3706E.pdf

AADE L-C Meter Probing at the end of a coax cable: What are the limitations ?  Graphs show the effect of a one foot length of RG-174 when measuring L and C's.  Also shows my home made SMT component probe.

Wideband Return Loss Bridges - Construction and Tests

Upgrading BOONTON models 92/42 RF Voltmeters   Replace the mechanical chopper and AC amps with chopper stabilized low offset op amps.

Useful Links

VE2ZAZ  Web  Site

AC6LA Dan Maguire  Excellent transmission line software:  TLDetails and others.

KE5FX  Web  Site  KE5FX  Web Site  Interesting GPIB Software and Time-Frequency Measurements

DL4YHF  Audio Spectrum Analyzer Software - Spectrum Lab

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