I observed the same thing with a small CW SSTC:
Thermal Imaging a Tesla Coil
https://youtu.be/K2wgONalxgU
Not sure of an explanation.
Brian
Sent from my iPhone
> On May 19, 2019, at 11:37 AM, <jan@xxxxxxxx> <jan@xxxxxxxx> wrote:
>
> Hi, I recently made a very simple measurement on my coil
> www.sthlmteslacoil.se <http://www.sthlmteslacoil.se> with my
> IR-thermometer. After a few minutes of running, the top of the secondary was
> at room tempoerature (20 degrees), while the bottom part was at 30 degrees
> celsius. I can´t find any other explanation besides that the current could
> be much higher at the bottom part and therefore cause local resistive
> heating of the magnet wire.
>
>
>
> What is the current standing in the debate about tesla coils being quarter
> wave resonators as opposed to simple lumped LC-circuits? If they are quarter
> wave resonators the current would be much higher at the bottom, but not if
> they could be modeled as lumped circuits.
>
>
>
> The main documents I have found from when the debate was hot twenty years
> ago are these:
>
>
>
>
> <http://hotstreamer.deanostoybox.com/TeslaCoils/MyPapers/smallar/smallar4.ht
> ml>
> http://hotstreamer.deanostoybox.com/TeslaCoils/MyPapers/smallar/smallar4.htm
> l
>
>
>
> www.tuks.nl/pdf/Reference_Material/Corum/RF%20Coils,%20Helical%20Resonators%
> 20and%20Voltage%20Magnification%20by%20Coherent%20Spatial%20Modes%20-%202001
> .pdf
> <http://www.tuks.nl/pdf/Reference_Material/Corum/RF%20Coils,%20Helical%20Res
> onators%20and%20Voltage%20Magnification%20by%20Coherent%20Spatial%20Modes%20
> -%202001.pdf>
>
>
>
> They both seem quite convincing to me, but are totally copntradictory. What
> is the current standpoint on these issues? Are there any alternative
> explanations to the heating of the bottom part of my coil?
>
>
>
> Regards,
>
> Jan
>
> Stockholm, Sweden
>
>
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla