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SITE WEB Électronique et Radio-amateur
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Jacques Audet VE2AZX
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Electronics and Amateur Radio WEB SITE
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SITE WEB Électronique et Radio-amateur
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Jacques Audet VE2AZX
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Electronics and Amateur Radio WEB SITE
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Notre site de voyages Commentaires ? Questions ? Écrivez moi !
Documents en français Equipments et pièces à vendre SERVICES TECHNIQUES
Présentation sur les Baluns et Ferrites (Mise à jour Mai 2023) 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 et utilisation. Cette sonde permet de mesurer facilement les courants circulant sur le blindage du câble coaxial et sur les conducteurs de l'antenne.
Vérifiez vos ferrites avec votre analyseur SWR/TOS Comment on peut facilement vérifier l'impédance effective d'une ferrite. On peut aussi mesurer l'impédance des antennes dans la gamme de 10 à 500 ohm. Ce lien montre les calculs.
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
Quelques trucs avec les transformateurs Augmenter ou diminuer la tension de sortie, ajouter un enroulement, transfo de courant, étalonner un ampèremètre.
Mesures d'impédances en utilisant un générateur de signal et un oscilloscope. Utilise un pont résistif (6 résistances) pour mesurer l'impédance complexe (résistance et réactance +/-). L'utilisation d'une feuille de calcul Excel simplifie le travail et calcule aussi les valeurs série/parallèles des composants. Des fichiers .pdf et mathcad montrent les dérivations que j'ai faites.
Référence: https://www.youtube.com/watch?v=eYN7dhdt1Dw
Sonde Différentielle Haut Voltage Cette sonde (en KIT ou assemblée) permet de mesurer de petites différences de tensions existant entre deux points qui peuvent avoir une tension commune jusqu'à 500 Volts maximum. Basé sur l'ampli différentiel AD8479 de Analog Devices. Écrivez moi pour plus d'informations.
Filtre R-C pour diminuer le bruit sur votre oscilloscope et autres (mise à jour jan. 2021) Différents filtres R-C de type passe-bas/passe-haut et notch ajoutés.
Sonde Courant PROVA CM-05 Mesure de la réponse en fréquence. Fichier Excel. (Nouveau Fév. 2021)
Multimètres HP haut de gamme. Évolution des multimètres HP, Agilent et Keysight à partir des années 1970. (Nouveau Fév. 2021)
Mesure et Calculs de la perte d'atténuation S21 (Insertion loss): Théorie de base montrant le calcul de S21 et le rapport des tensions E21. (Nouveau Fév. 2021)
Utilisation des nombres complexes en électronique Un peu de théorie sur les filtres de base. (Nouveau Août. 2024)
English Documents Equipments and Parts for Sale
Comments ? Questions ? Email me !
My presentation at Boxboro Sept. 2019: Get the most from your Antenna Analyzer
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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.
A high Isolation Common Mode Choke/Balun This HF choke provides an isolation impedance well above 10000 ohms. It was built from info from Ian White GM3SEK. The last three pages show how to measure the choke/balun impedance.
A Low Frequency Common Mode Choke/Balun Useful from 50 Hz to 10 MHz. Common mode impedance is > 5K ohms from 20 KHz to 4 MHz. Helps removing the common mode noise when using sound cards.
Impedance Calculations in the Series mode Here I provide the derivations of the formulas shown in the above Baluns and Ferrite presentation and the High Isolation Common Mode Choke.
Check your Ferrites with your SWR Analyzer Describes an easy to build fixture that allows you to quickly verify the effective impedance and material type of ferrite cores. Of course it may also be used to measure the impedance of antennas in the 10 to 500 ohm range. This link shows the theory behind.
MFJ-206 Current Probe Schematic and user info 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.
Home Made Current Probe 100 KHz to 50 MHz using an Irwin Clamp. The output level is 1V/Amp. (New Jan. 2023)
External Current Probe for the MFJ 854 100 KHz to 50 MHz using an Irwin Clamp. Much easier to use ! (New Jan. 2023)
Transmission Line Stuff - Q Factor
Measure Cable Zo with an SWR Analyzer, with an L-C Meter, with a VNA or with a home made TDR. Four techniques for measuring cable impedance.
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.
Calculate K0, K1 and K2 coefficients, Losses, Dielectric Loss Tangent, Q factor for short lines and quarter wavelength lines An Excel spreadshet does these computations for open and shorted lines, for common coaxial cables, using your measured data. Also includes computation of distributed C and L as well as delay.
Calculate the Loaded and Unloaded Q Factor of a Resonator. Excel spreadsheet. Enter the resonant frequency and loss, plus loss at a second frequency.
Calculate the Equivalent Q Factor of Cascaded Resonators Added resonator insertion loss calculations. Applies to a pair of resonators on the same frequency. Excel spreadsheet.
Q Factor Measurements 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. Published in QEX jan. 2012. Link to spreadsheet here.
Detailed Calculations regarding the above article: Q Factor Measurements with an SWR Meter. Pdf file shows Mathcad Calculations.
Measure the Q factor from Impedance Data This Excel spreadsheet does Q Factor calculations based on a set of measured impedance values, without knowledge of the circuit configuration. Includes series and parallel resonance modes.
Measure Impedances with a Q Meter This Excel spreadsheet calculates series and parallel impedances from Q meter measurements of Q and resonant capacitance. (Updated Sept. 2022)
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.
Calculate Line Length based on Degrees Calculate the actual transmission line length when the length is given in degrees. Also shows how to calculate the transmission line parameters. (Updated July 2024)
Calculate Quarter Wave and Half wave Line as well as the Velocity Factor Calculate the velocity factor and quarter / half wave resonant frequencies. (New Jan. 2024)
Antennas
Portable
Vertical Antenna for 40m and 75m It
uses elevated radials and an umbrella that serves as a capacitive hat to cover the 75m
and 40m bands.
Modeling results are also shown as well as measured data compared to a standard car rooftop vertical.
Variations in the basic design are explored with actual component values shown.
Additional Info on the Portable Vertical Antenna Tuner construction, antenna assembly procedure and more pictures.
Multiband Loop Antenna
Here is a compact, low height, vertically polarized,
low noise DX antenna, working on 10, 15, 20 and 30 meters.
No radials are required. The author goes thru the impedance measurements,
simulations and comparaisons with other wire antennas.
Excel Spreadsheet eases Designing L-C Traps Useful to resonate an antenna at two frequencies above and below the self resonant frequency. Requires two measurements.
IMPROVED MATCHING OF A SEVEN BAND ZS6BKW TYPE ANTENNA (New Dec. 2023) An L - C - L matching circuit removes the need to add a length of transmission line.
Frequency Standards - Measurements
Off the Air Frequency Measurements FMT Shows how to use Spectrum Lab software for precise frequency measurements, My set-up and examples of an Excel file to process the measurements. Describes some of the hardware that I use.
Off the Air Precision Frequency Measurement, Transceiver Calibration and FMT By George K1IG. Shows how to calibrate your transceiver to 1 Hz accuracy, using your transceiver, your computer sound card and software like Spectrum Lab.
Modifications and Analysis of VE2ZAZ Frequency Standard Also describes my own implementation of VE2ZAZ frequency standard in the HP 5328A counter.
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 Shows the electrical and mechanical design as well as test results on my new GPS frequency standard, using the VE2ZAZ controller. Also shows my outdoor GPS antenna.
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.
Bandpass Cavity Resonators Using bandpass cavity resonators for impedance matching. S parameter measurements and modelling.
Coupling Loops for Duplexers Shows the influence of different loop shapes on the insertion loss.
Bandpass/Bandreject Resonators Simulations vs measurements. Impedance plots show how it really works.
RepeaterSensitivity - De-Sense Tests Testing RX sensitivity degradations caused by antenna noise pick-up and TX signal feeding back into RX. Build a high performance signal sampler. GE Master II front end helical filter measured response.
HELP - Receiver Noise Raises when the Repeater Antenna is Connected ! Here are the e-mail exchanges I had with Carl (name fictive) regarding this problem. Many areas for solutions have been explored. I feel it might help other people that have similar problems.
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.
HF L/C Bandpass Filters Two simple circuits using a single variable capacitor.
Hi-Q Variable Audio Filter (900-1100 Hz, 5 Hz wide) This bandpass amplifier / filter uses an op-amp to provide 40 dB gain. It is based on the Hall network.
Looking for an AM Band Rejection filter like the Clifton Labs Z10020B ? I can build one for you. Please email me !
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. (Updated Feb. 2023) Details of the calculations.
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 reflection coefficient data (dB/angle or Re/Im S11) to Return Loss, SWR, Real and Imaginary components and equivalent series/parallel L or C values. Also provides Q calculations and plots.
Measure Complex Impedances from 0.01 ohms to 100 K ohms with your VNA. This Excel spreadsheet uses S21 Real / Imag. or dB / Angle parameters. Measurements are done in series and shunt configurations, over the frequency range in use. I have added pictures of the test fixtures that I use. This sheet computes the series and parallel component values, the impedance magnitude and the Q factor for every frequency.
Mesures Complex Impedances using a Signal Generator and a Scope. Uses a resistive bridge (6 resistors) to measure complex impedances (resistance and +/- reactance). An Excel spreadsheet simplifies the job and calculates series/parallel component values. Pdf anf mathcad files show the derivations of the formulas that I use. Référence: https://www.youtube.com/watch?v=eYN7dhdt1Dw
Convert Series Impedance Data to Parallel Values Convert series R, L, C values to their parallel equivalent. (New Dec. 2023)
Low Frequency Adapter for your VNA - QEX Article (Jan-Feb 2015)
Specifications, Circuit Schematic, Parts List, Assembly and Test Procedure, X100 Divider and more
INSTRUMENT EVALUATIONS
Evaluation of Clamp Multimeter UT210E Inexpensive. Measures AC and DC current with a 1 mA resolution. Besides AC/DC voltages and resistance, it also measures capacitance.
Current Probe PROVA CM-05 Measured frequency response. Excel file.
Nano VNA Test Results S11 and S21 Accuracy tests, using calibrated 18 GHz attenuators and HP8753D VNA.
HP 4342A Q Meter Tests and Driver Transformer Construction. (Updated Feb. 2023) This document reviews the extensive tests done on the Q Meter. It shows that the source resistance is far from being constant at 1 milliohm. It increases with frequency at 130 milliohms at 50 MHz. This Excel file allows correcting the Q readings for both the HP 4342A and the Boonton 260A. The details of the calculations here.
Voltage Regulation and Noise Plots as Measured on some Power Supplies and AC adapters (New Dec. 2023) Test results with graphs on many common AC adapters show that they are all different.
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
HP 8753 VNA Measure Impedances directly in ohms, using the conversion mode
FULL S Parameter Data for common transistors Covers from 30 KHz to 500 MHz. Transistors: 2N2222, 2N3904, 2N3906, 2N3933, 2N3962, 2N930, 2N4416, 2N4929, 2N5109, 2N5320, BFR30, BFR91, BFR96.
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 Three models shown, covering below 20 KHz to greater than 2000 MHz, along with test results.
Upgrading BOONTON models 92/42 RF Voltmeters Replace the mechanical chopper and AC amps with chopper stabilized low offset op amps.
Schematics of Boonton RF Probes (updated jan. / Feb. 2021) As used in Boonton RF voltmeters and power meters.
Boonton 50 ohm N Adapter Home made 50 ohm adapter that goes up to 1 GHz. For use with high impedance Boonton probes.
Great document on Boonton Probes and others From Novotill website.
Build your own wideband RF Sampler Resistive sampler covers DC to 2 GHz.
Compute Low Frequency Parameters of Resistive Attenuators with 3 DC Resistance Measurements. As published in Electronic Design Magazine. Link to Excel sheet.
Checking your Digital Multimeter Calibration The DMMCheck Plus provides for checking the calibration on DC/AC Voltage and Current, as well as four calibrated resistors. I have modified the unit by using the calibrated resistors to make a resistive divider, providing more calibration voltages. The Excel sheet does the tedious calculations for you and the .pdf file details the formulas that I used.
My Labview 6 VI's files For HP 8753D VNA, HP 3336B, HP 5334B, HP 59501A DAC, HP 11713A Atten Driver, SMHU Sig gen, HP 3478A, HP 3456A, and HP 34401A. (Use at your own risks !)
Drake DL-1000 Dummy Load Modifications Improves SWR which remains low up to 450 MHz. Adds 30 dB and 40 dB attenuator output with external frequency compensating pad.
Differential High Voltage Probe This probe (KIT or assembled) allows measuring small voltage differences on top of higher voltages, up to 500 Vpk. Based on the AD8479, Very High Common-Mode Voltage Precision Difference Amplifier, which includes internal precision resistors. Contact me for info.
Wideband Resistive Probe This is a home made resistive probe with a bandwidth that extends beyond 2.5 GHz.
A Wideband Amplifier with high input impedance Provides 1 Mohms, AC/DC coupling or 50 ohms. Frequency response extends beyond 200 MHz. Gains of X1 or X10 are supported and it will drive 50 ohms loads. P 1dB compression is around +16 dBm at low frequencies.
Low Noise Preamplifier is based on the LT1115. Provides gains of X100 or X1000. (New Dec. 2022)
Low Noise AD825 Fet Input Amplifier. Provides X1 and X10 Gains in the MHz range. (New Dec. 2022)
Calibration Techniques for the Home Lab This presentation is a collection of ideas based on my personal experience in the calibration of common test instruments. Presented at the 2018 Boxboro Convention. Excel file for measuring capacitors: here. New Mar 2022: Added page 32, Updated pages 41, 42 showing 34461A DMM
Useful Links
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
