EFHW power rating myths

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You can determine the power rating for yourself. Don't rely on myths and exaggerations.
Watch these videos to fully understand this problem.
This video gives you background information on power rating.
• EFHW Antenna Power Rating
This video explains how the non-linearity of ferrites generate illegal spurious emissions.
• EFHW Spurious Emission...
This video shows how to measure illegal harmonics with a spectrum analyzer.
• EFHW emissions violate...
This video explains how thermocouples work.
• Thermocouples, how the...
This video demonstrates a low cost thermocouple meter and demonstrates why infra red (IR) temperature measurement depends on the emissivity of the object.
• Thermocouple Meter Rev...
Here is a link to part 2 of this video:
• EFHW Power Rating Myth...

Опубликовано:

6 сен 2024

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Комментарии : 23

@xtogarcia1463 Месяц назад

Muy interesante.Este tipo de experimentos explican muchas paradojas y mitos extraños de la radioafición. Gracias por su tiempo, compartir e interés.

@neilbchilton 7 месяцев назад

Thanks Jim, this is really useful information. I think you're the only person covering it in this level of detail. I'm looking forward to the next video where we see the actual temperature increase in the ferrite... and dummy load I guess. I've often thought it strange that none of the commercial transformer designs consider cooling or passive heat transfer. I only use QRP right now , but still very interesting! 73s

@Jimscoolstuff 7 месяцев назад

Thanks for your comment. 73

@mareksp9tkw908 7 месяцев назад

Thank you Jim for detailed explanation and crush reminder course is basic thermo-physics. Looking forward to part 2.

@Jimscoolstuff 7 месяцев назад

Thanks for your comment.

@jbammi 2 месяца назад

Thanks Jim, Very interesting topic like most of your videos and really marvel at the innovations you come up for the jigs for the metrics you are trying to measure. Curious about one thing: When you measured the ferrite code temperatures you ran the rig key down 100% duty cycle. Wouldn't a more realistic model use the duty cycle of say a digital mode - FT8 15s on / 15s off, or for FT4 shorter on/off cycles? Also, as you point out most transformers come in a enclosed box for weather/dust protection, or the QRP ones shrink wrapped around some sort of support like a winder (yes there are some unprotected ones wire wrap tied to a support. Keep them coming and we'll keep on learning. Thanks again 73 de k1jbd, bammi

@Jimscoolstuff 2 месяца назад

In part 2 of this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-I1ePw6PQ0io.htmlsi=lN4rnKtSCqU7Hxg- I use FT8 to show temperature rise and the SWR heading toward infinity. Thank you for your comment