Radio coils - Q- Damping- Impedance- Resonance, the very basics
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- Опубликовано: 13 авг 2015
- Earlier video (reference): ""why an oscillator? (shortwave technology & measurements"" uploaded 30 july 2015.
The video shows a few very basic thoughts about coils, their Quality factor (Q), their Impedance in a certain electronic circuit and their resonance frequency. Also the fact that a coil never works in a electrical/electronic/electromechanical "vacuum". This means that the input and output impedance from a coil (antenna coil, IF coil, choke coil, transductance) must always be taken in account. That is why coils have completely different properties, sizes, inductances, forms, regarding their specific application (radio, choke, IF, power transformer, transductor, etc.
nb: the showed coil does not oscillate in the given circuit without the ferrite rod that lifts the inductance to a high value and brings down the resonance frequency. That does not mean that the coil without the ferrite core (see video) will never oscillate! I am sure it will oscillate with a FET or tube or another transistor in a more specific circuit made for high frequencies, HF. 
Наука
I really enjoy your explanations. Some of my oscillators work and some don't this will really help
One of the most common reasons for not working 1 transistor oscillators is that the voltage divider at the base from the transistor is not variable.
always fun to watch your videos
Thankyou. If you hook up a small power supply to a tank circuit (coil and capacitor, a naturally tuned to one resonant/oscillating frequency due to the characteristics/physical/electrical dimensions of it) and briefly turn it on and off, you should see the fundamental waveform on an oscilloscope, and you will see the amplitude of that being "damped" or reduced over time due to internal resistance of the wire, etc. I think some coils wont oscillate because the capacitor just cant hold enough energy and due to the resistance of the wire in the coil that takes up alot of the available power.
trailkeeper Thanks, a good idea!
AWESOME
Can you have the coil pulse in a Resonance with out that rob in side the coil.
When the oscillator circuit is able to let the coil oscillate: yes.
if soo tell me the rude of how many turn i need in the coil to make this work? and how do i calculator how much power do i need to make this pulse or make a feild? EMF
Hoi, hoe meet ik de weerstand van een zelf gemaakte loop antenna? Groetjes
Ik weet niet precies welke weerstand je bedoelt.
Vraag is/was dus: waar gaat die loopantenne werken? Vermoedelijk bedoel je niet de gelijkstroomweerstand, want die kun je met een Ohmmeter meten, maar iets anders.
@@radiofun232 Hoi, nou ik ben bezig met een klein project waar ik al een tijdje aan werk. Ik moet een circuit maken dat een 125 kHz sinusgolfsignaal kan versterken om deze vervolgens op een zelfgemaakte magnetische lusantenne te plaatsen. Dit is in feite een RFID-versterker, maar er hoeven geen gegevens te worden verzonden; Ik wil alleen het 125 kHz-signaal versterken en het een zo groot mogelijk magnetisch veld laten maken, zodat het een ontvangstcircuit op enkele meters afstand kan activeren. Alleen kom ik er niet uit wat voor versterker te gebruiken in combinatie met de antenna's. Via het internet heb ik van die reken tools gebruikt om de inductie waarden van de antenna's te berekenen en daar heb ik dan ook verschillende capacitoren bij om ze te laten resoneren op betreffende frequentie. Alleen de eventuele weerstand die de antenna eventueel zou geven aan de versterker blijft me onbekend.
@@stortregen5390 OK, dat geeft meer helderheid. Het beste is om het gewoon te bouwen en dan de zaak af te regelen op maximale resonantie. Dus dat de antenne "piekt" op die 125 KHz. Dat gebeurt in jouw geval (denk ik) met de parallelcondensator (in theorie kan het ook met een seriecondensator). Door die aan te passen kun je de loopantenne op 125 KHz laten "pieken" (=maximale energie laten uitzenden=afstemmen). Ik denk dat men in dat rekenprogramma de "golfweerstand" van de antenne bedoelt, maar die hangt af van de afstemming van de antenne. Als de zendantenne het maximale signaal afgeeft is de zaak in orde. Als de antenne niet goed is afgestemd op de zender (geen staande golven) wordt een deel van het uitgezonden signaal gereflecteerd in de kabel en "terug naar de zender". Dat geeft verlies, de zender reikt dan minder ver. Ik denk dat men dat bedoelt in dat rekenprogramma (golfweerstand). Zoek eens op de term "staande golf meter" op het www.
Dit is een goede website
www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/cq-pa/1971/page483/index.html
Maar het gaat daar wel om een staande golf meter voor hogere frequenties, dus niet voor 125 KHz.
Niettemin: de principes van de zendtechniek (resonantie op een bepaalde frequentie van een zendantenne) en kabelreflectie en golfweerstand van een antenne zijn gelijk.
How ican matching with lower imput impedance ,mean calculate number turn to secondary
what do you mean exactly?
@@radiofun232 I would like to know how to adapt this antenna to a base impedance input
@@salahibrahim633 You can couple an antenna coil to the base of a transistor via a coupling capacitor. Often (say) 100 pF. When you connect an antenna to the coil it has an effect on its resonance frequency. A FET (field effect transistor) works best. There are a lot of video's on my channel about radio's, antenna HF amplifiers (max. 18 MC) etc. Go to the "looking glass" on my channel trailer (Radiofun232 on You Tube) and search with keywords like "radio" or "shortwave" "antenna" etc. I will try to give some links. I hope that this is an answer.
active antenna is here ruclips.net/video/lWGIsmFWS7U/видео.html
In the schematic of this radio you see how the antenna coil is coupled to the first transistor ruclips.net/video/BDlRG6U5sYU/видео.html
LINKS TO VIDEOS WITH SCHEMATICS ON MEASUREMENT TECHNIQUES & TESTS
Analog frequency meter 45 Hz-19 KHz pt 1 ruclips.net/video/vm5JlyWqac4/видео.html
Analog frequency meter 45 Hz-19 KHz pt 2 ruclips.net/video/hNikBHDJwg4/видео.html
Test device to get insight in transformers and higher inductance coils ruclips.net/video/u9sP_b5Rfvo/видео.html
Getting more insight in radio coils with a FET oscillator ruclips.net/video/LrJWLe1XrSI/видео.html
Device to test radio coils on their Q (quality factor) ruclips.net/video/HR-apI_ZkKU/видео.html
Experimental SWR (standing wave ratio) meter on 27 MHz ruclips.net/video/ErIQmRDA4go/видео.html
RF absorption meter demo + schematic ruclips.net/video/fOnlyU2Qlwg/видео.html
Inductance measurement 1,2 uH - 180 uH + Q test ruclips.net/video/_iDtm8EhRRg/видео.html
Test oscillator sine wave with very good linearity 200 KHz-9 MHz ruclips.net/video/Ng49kGF3n8o/видео.html
The easiest way to test an IF can on 455 KHz ruclips.net/video/vyHWUt3UzTs/видео.html
Radio coils and dipmeter demo ruclips.net/video/g6QWsL9SNzY/видео.html
Radio coils, properties, basics, examples ruclips.net/video/Roi4qloauVE/видео.html
Testing IF coils on 455 KHz with an oscillator ruclips.net/video/ZRsD7pzhu6c/видео.html
What do you need for an electronic lab? ruclips.net/video/v503bmymCWw/видео.html
How to make a precision analog voltmeter part 1 ruclips.net/video/pfi5N-rkS8c/видео.html
How to make a precision analog voltmeter part 2 ruclips.net/video/5Dk1NMz-LQs/видео.html
How to make capacitors from 1-300 pF and measure them ruclips.net/video/4rD4J2kV854/видео.html
Oscilloscope: how to make a very basic one ruclips.net/video/4V3IXhTFqIM/видео.html
How to make a 455 KHz IF filter yourself and wobbulator it ruclips.net/video/P3zzuf9p8hI/видео.html
What to do with broken analog voltmeters? ruclips.net/video/XXCePo0ZIfk/видео.html
Test oscillator for coils ruclips.net/video/K2nkqnrwD7o/видео.html
Measuring inductance (0,4 uH-169 uH) via a frequency counter ruclips.net/video/ExikurAQKpY/видео.html
How to make a shunt ruclips.net/video/FN59W9SGou4/видео.html
Prevent transistor leads from breaking ruclips.net/video/iEe37oz4tww/видео.html
Testing IF cans/how to find out their properties ruclips.net/video/hOSRIJjHunI/видео.html
Measuring the health of a N-MOSFET with a Ohms-Voltmeter ruclips.net/video/cRtT5c_bkUI/видео.html
Electronic effects made visible ruclips.net/video/_f5sSOE3ijc/видео.html
Developing a precision capacitance meter ruclips.net/video/qhyqHk8wXJs/видео.html
Passive diode testing, part 1 ruclips.net/video/EI0-fj--Jjk/видео.html
Passive diode testing, part 2 ruclips.net/video/oKIcbubaUWw/видео.html
Silly MOSFET testing ruclips.net/video/QAvuZXjPNLM/видео.html
Diodes, common info ruclips.net/video/t_KztxcLXmc/видео.html
Digital frequency meter made from a radio with a digital display ruclips.net/video/5MzdJR19S7Y/видео.html
N-MOSFET (power type) tester (passive) ruclips.net/video/t25qwvHDDXE/видео.html
IF 455 KHz filter test with a wobbulator ruclips.net/video/crfK_DgSfGs/видео.html
Test from a 455 KHz IF filter (oscillator) ruclips.net/video/5wuHmHNESoY/видео.html
Extended scale precision voltmeter pt 1 ruclips.net/video/-z_j4MclCTk/видео.html
Extended scale precision voltmeter pt 2 ruclips.net/video/fC1QP_6OlAM/видео.html
Wheatstone bridge demonstration circuit ruclips.net/video/Y3-Mhil1uzY/видео.html
How to figure out an unknown transformer, part 1 ruclips.net/video/ceHe_0iuh_Y/видео.html
How to figure out an unknown transformer, part 2 ruclips.net/video/IDV530fM_oM/видео.html
Dipmeter: search the resonance frequency ruclips.net/video/QVTmiFbf7Gc/видео.html
Inside the Ferraris meter ruclips.net/video/i_ed0lgzfjw/видео.html
Do audio capacitors have a certain sound? Part 1 ruclips.net/video/nHtIg-0DQLU/видео.html
Do audio capacitors have a certain sound? Part 2 ruclips.net/video/4nylOtSATPk/видео.html
Do audio capacitors have a certain sound? Part 3 ruclips.net/video/rdpsjvYv4wg/видео.html
How to use a frequency counter, part 1 ruclips.net/video/0yfI5rRV3Pk/видео.html
How to use a frequency counter, part 2 ruclips.net/video/30Sowpu64ec/видео.html
Effects from coupling capacitors in audio circuits ruclips.net/video/eF8e-FmtDh4/видео.html
How to measure AC current ruclips.net/video/PWPqp3wHiS4/видео.html
Testing PVC tape on high voltage ruclips.net/video/RwmArfBUc8o/видео.html
Integrator and differentiator circuit, sound effect ruclips.net/video/OKCpDdwrhGY/видео.html
how to test switches on high currents ruclips.net/video/9rus9UnnL8M/видео.html
Inductance meter 0,4 uH-170uH for radio coils ruclips.net/video/THvEqSAKD6Q/видео.html
Measuring the resonance of a quartz crystal ruclips.net/video/vv2Xcjga_Vc/видео.html
MOSFET fundamentals (static test) ruclips.net/video/YUF7bwqNK28/видео.html
Inductance meter 1mH-100mH schematic ruclips.net/video/vi041V0oiR4/видео.html
Effect from clouds on a solar panel ruclips.net/video/Ub8G8E_IU9o/видео.html
Radiofun 232 on You tube, all channel info and links ruclips.net/video/xbgQ8T3oqh4/видео.html
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