Is my tuner fooling my radio? Part 1: how a tuner works
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- Опубліковано 10 вер 2024
- This video shows the process that allows a tuner to adapt the impedance of a mismatched load.
You can find the online impedances calculator at this link: www.iz2uuf.net...
Here an article on this topic on my blog: www.iz2uuf.net...
Part 2 is at this link: • Is my tuner fooling my...
Ottimo! Personalmente non sarei riuscito a far di meglio per cercare di spiegare l'argomento a chi ancora diffonde quei falsi miti. Al livello dei migliori video didattici sul Tubo! (Es. W2AEW).
Comprendo la tua scelta linguistica (ovviamente anche io non ho alcun problema con l'inglese) ma queste errate convinzioni sono molto più presenti tra gli om nostrani, soprattutto delle ultime generazioni, per il loro livello di preparazione tecnica sempre più basso e per questo preda di simili infondati miti.
This video was fantastic. Thanks, looking forward to #2.
Yes, in an ideal "lossless" capacitor, the resistance is that residing in the metal or conductor part of the capacitor. The dielectric is the insulator separating the conducting materials. So you want the least loss in the metal part - hence zero resistance, in the perfect, or ideal capacitor, and then no dielectric loss in the insulator, which means no losses in the dielectric caused by the AC, or high frequency voltage, across the plates. The dielectric loss is caused by movement of charge in the dielectric under the electrostatic forces from the voltage on the plates. The movement of electrons means that there is some unwanted currents in the insulator thereby resulting in heating, dielectric distortion, and thus loss. The electrons that are "free" to move in the dielectric indicates the dielectric is not a perfect insulator. The reactive value is given by the frequency and the quantity of capacitance (size of stored charge). So that will vary from a high reactance near DC and a low reactance, at a high frequency. The complex impedance of a capacitor is the value of the resistance and reactance of such a capacitor as described perfectly by IZ2UUF. Since there is no such thing as a perfect capacitor, the complex impedance will have some amount of R and dielectric losses - with the ESR, or series resistance, being a measure of how far from ideal the capacitor is. And we should not forget about the loss caused in the dielectric which also has the effect of altering the phase between the voltage and AC current in the capacitor. The resulting shift in phase has an angle value given by the Greek symbol "Delta", and the loss resulting is specified as the Tangent of the angle, or Tan (Delta).
The Real resistance (R) in an ideal capacior is not equal to zero, but is infinity! I am sure that it is a technical mistake, Otherwise, the video is very informative. Congrats!
Hello Mile. The capacitor has infinite resistance at DC. At AC, in the field of complex numbers, the impedance is expressed as a resistance (called ESR) in series with a reactance. An ideal capacitor has ESR (i.e. the R part of the complex impedance) set to zero. Go to the picture at 8m16s where the tuning is done assuming ideal components. Now, replace the ideal capacitance R=0 X=-233.55 with R=infinite X=-233.55 and see what happens.
If you work with complex impedances, at DC it is NOT THE RESISTANCE to be infinite but the REACTANCE. If you calculate the reactance a f=0 (see formula at 7,33s) you have Xc=1/-(2 PI * f * C); being f=0, we have Xc=1/0=infinite.
At the same time, if you calculate the reactance of an inductor at DC you hav XL=2PI*f*L=2PI*0*L=0.
You can verify this for example here: www.capacitorguide.com/impedance-and-reactance/
From that point of view, it makes sense. Regards!
Great video, can’t wait for the part two.
Nice vid
Any idea when Part II will be out? VERY impressive video, planning to show it at our next local club meeting (with your permission, of course) and would love to be able to show Part II at the same time. Any chance Part II will be ready before Sep 9th? Thanks!
Yes, I expect tomorrow to be online. Thanks. 73 de Davide IZ2UUF
Great Video!!! :)
Very cool. 73 de DO9HC
Fooling my radio? When I use my tuner, the station on the other end says my signal goes up (sometimes as much as 20 dB). So, I guess I'm fooling his radio also.
as the tuner presents a lower swr , your tranceiver my have protection circutry that now allows power output to ramp up
About 5 minutes in, your video says an ideal capacitor has R=0 and X >0. This is incorrect. In an ideal capacitor, R=infinity.
Hello Chuck. Thanks for your comment. See the anwer to Mile Kokotov below.
Pronounce "series" as "seeerrrEEEES". Just trying to help.....