Timeline for Why does an RF Amplifier fail when the SWR is high?
Current License: CC BY-SA 4.0
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| Aug 30, 2019 at 3:33 | comment | added | hotpaw2 | Depends on the circuit. But, depending on mismatch and phase, each lossless reflection could potentially worse case double the voltage at a reflection point somewhere in the circuit. Rinse and repeat for multiple return reflections. Perhaps ending with a voltage well over design spec somewhere in the finals circuit. | |
| Aug 30, 2019 at 0:41 | comment | added | Andrew | Does the reflected energy get dissipated inside the output transistor ? If so, can you explain to me how this happens exactly ? does AC current flow into the collector ? ... | |
| Aug 30, 2019 at 0:39 | comment | added | Andrew | This comment is getting closer -> "Thus, energy has to be dissipated somewhere. So, if the transmitter doesn't fold back the power level to below what the feedline and the heatsinks can radiate away, something will melt or otherwise stop functioning due to overheating." | |
| Aug 30, 2019 at 0:38 | comment | added | Andrew | Most of this to me seems not relevant to my question. | |
| Aug 23, 2019 at 15:41 | history | edited | hotpaw2 | CC BY-SA 4.0 |
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| Aug 21, 2019 at 23:54 | comment | added | Phil Frost - W8II | And what's to say there isn't such an impedance mismatch? | |
| Aug 21, 2019 at 23:28 | history | edited | hotpaw2 | CC BY-SA 4.0 |
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| Aug 21, 2019 at 23:20 | comment | added | hotpaw2 | It only makes a second trip up the feed line if the transmitter reflects it due to yet another impedance mismatch. | |
| Aug 21, 2019 at 23:02 | comment | added | Phil Frost - W8II | High SWR does not mean the energy isn't being radiated. It just means it makes more than one trip down the feedline before it finds a way out. What fundamental law says it has to be absorbed by the transmitter, versus making another pass at the antenna? | |
| Aug 21, 2019 at 18:35 | history | edited | hotpaw2 | CC BY-SA 4.0 |
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| Aug 21, 2019 at 18:28 | history | edited | hotpaw2 | CC BY-SA 4.0 |
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| Aug 21, 2019 at 18:20 | history | answered | hotpaw2 | CC BY-SA 4.0 |