04-01-2014, 07:15 PM
What happens when reflected power from a transmission line/antenna mismatch gets back to the transmitter, I'm getting conflicting views when researching it on the web.
Lawrence.
Lawrence.
Reflected Power?
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04-01-2014, 07:15 PM
What happens when reflected power from a transmission line/antenna mismatch gets back to the transmitter, I'm getting conflicting views when researching it on the web.
Lawrence.
04-01-2014, 08:01 PM
It is my understanding that the effect is one of two possibilities - 1, it cancels out the incident (or forward) power to a certain extent, this then causes the output stage to work into an incorrect match, which long term ends up in failure.
2, it comes back to the tranmitter and "adds" to the incident power, causing a similar failure. Either way, it is not a good thing, which is why minimised reflected power is most important.
04-01-2014, 08:39 PM
So is it the fact that the source is working into an incorrect impedance that can cause damage to a transmitter or is it that the transmitter "absorbs" the reflected power that does the damage?
Lawrence.
05-01-2014, 12:30 AM
Many years ago as a schoolboy in South London I was lucky enough to get a guided tour of the underground transmitter tunnels at crystal palace. ... we were shown a section of aerial feeder about 6 inches in diameter that had been part of a catastrophic failure. The reflected energy had setup a standing wave that had punched holes in the cable every half wavelength - apparently the noise was deafening
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05-01-2014, 12:53 PM
An very interesting read, dispells a few assumptions maybe?
http://homepages.ipact.nl/~pa1are/tuner/reflections.pdf Lawrence.
11-01-2014, 09:33 PM
Thanks for the link pwdrive, some of it took some getting my head round but I stuck with it..
12-01-2014, 08:54 AM
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