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Does feedline length affect SWR?
“the length of the feedline will not change the swr it will change the apparent reading depending on what wave length you read the swr at. . just as adding a signifigant length of coax, the resultant loss will look like a lower swr.”
How does coax length affect SWR?
What can cause erratic changes in SWR readings?
Tags: feedline
- The transmitter is being modulated.
- A loose connection in an antenna or a feedline.
- The transmitter is being over-modulated.
- Interference from other stations is distorting your signal.
What are the errors possible in standing wave ratio measurements?
Possible Errors in Measurements: 2. Depth of the probe in the slotted line carriage is made as minimum. If not, it may cause reflections in addition to the load reflections. For the device having low VSWR, connector used for measurement must have proper matching with line impedance.
What is an acceptable SWR reading?
SWR 1.0-1.5: The ideal range! If your SWR is under 1.5, you’re in great shape. SWR 1.5 – 1.9: There’s room for improvement, but SWR in this range should still provide adequate performance. Occasionally, due to installations or vehicle variables, it’s impossible to get SWR lower than than this.
How does the length of the cable affect SWR?
I,m no tech but I will say that if the equipment is 50 ohm and the antenna is 50 ohm then the cable length makes no difference. I have run length from 5 ft to 25 ft in an odd assortment of length with very little or no SWR change. I will get lambasted for this but Oh Well. The Peddler…
What makes a good SWR with a mismatched load?
Measurement location giving the appearance of “good SWR” with a mismatched load. When you key your transmitter, the transmitted (incident) wave travels down the coaxial cable and meets an impedance mismatch (in the above case, an open circuit) and no current is leaving the cable since there is no load.
How can you tell the SWR of an antenna?
This is a old trick to make antennas look like they have a very good SWR and wide bandwidth. This can be proven with a antenna analyzer or SWR Meter, by measuring the SWR and bandwidth right at the antennas connector. Then taking say 50 or 100 Ft of coax and measureing the SWR and Bandwidth again. You will see a differance.
How does adding coax to an antenna affect SWR?
If the antenna is matched to the coax, then it is said to be flat or have no SWR. In this case adding or subtracting coax is not a big deal. However if a significant amount of coax is added to a perfectly or not perfectly matched antenna, then the SWR measurement will show a lower SWR and a wider bandwidth.