Questions tagged [transmission-line]
71 questions
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Is there an optimum transmission line length for maximum power transfer?
Consider a typical source -> transmission line -> load (i.e. TX->transmission line->antenna) arrangement and assume that the load is not matched to the transmission line characteristic impedance.
It's always possible to select a length of…
Chu
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Can I use speaker wire as a transmission line?
Speaker wire is really cheap and available everywhere, and it doesn't seem that different to 300 ohm twin lead. It seems to me it would make an excellent balanced transmission line.
What would the approximate impedance and loss be? Can I use a balun…
Andrew
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How Does a 1:1 Current Balun Stop Current Flowing on the Outside of Coax?
Does anyone know how a current balun, when connected between coax and a series center fed half wave dipole, prevents RF current from splitting up at the join between coax braid and balun and traveling down the outside of the coax ?
I have added…
Andrew
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What is the main source of error for SWR meters?
I have updated this question to make it simpler because i haven't seen an acceptable answer yet.
New Question.
The impedance seen at any point on a transmission line is E/R. If the SWR isn't 1:1 then the impedance changes along the length of the…
Andrew
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What Stops RF Current from a Transmitter Flowing along the Outside of the Coax?
Can anyone tell me, inside a transmitter, what stops RF current from flowing from the transmitter along the outside of the coax and causing similar problems as when a half wave dipole is connected to coax without a balun ?
Edit : added " from the…
Andrew
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Does SWR change along the length of a transmission line?
Wikipedia says "SWR is defined as the ratio of the partial standing wave's amplitude at an antinode (maximum) to the amplitude at a node (minimum) along the line".
Standing wave voltage nodes and anti-nodes appear at points which are odd and even…
Andrew
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Apparent Paradox about wave reflection in a transmission line?
The transmission line is without loss of length λ / 4, the load $Z_L$ is a short circuit and $Z_G = Z_0$.
At $t = 0$, an incident wave of voltage $V_1$ and current $I_1$ such that $V_1 = Z_0 * I_1$ travel to the load, before $V_1$ reaches plane B…
mpradio
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Is it true that standing waves on a transmission line don't cause failure of transmitting devices?
Actual standing waves have nothing to do with causing the output device in a transmitter to fail, in fact it's the reverse or reflected current which helped to create the standing waves which is flowing into the output device that causes the…
Andrew
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