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11th June 2020, 10:53 | #1 |
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Rover 75 Diesel Tourer, called Perseverance Join Date: Nov 2011
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Testing a Marine Band Radio Transmitter with a SWR meter
I have connected an SWR meter between the RT aerial and the aerial cable, with the TX connection to the RT, and the antenna connection ANT to the aerial cable.
I set the FWD/REF switch to FWD. I key the transmitter, and adjust the CAL rotary knob to get the SWR meter at the SET (100% full scale) position. However when I switch the FWD/REF switch to REF (to read the SWR reading), the SWR meter INCREASES to the stop (approximately 115% full scale). What am I doing wrong ? I am following the written instructions that come with the SWR meter. Last edited by MarkS; 11th June 2020 at 11:39.. |
11th June 2020, 17:36 | #2 |
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It could be it is a real reading and you have a fault in the antenna system.
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11th June 2020, 18:04 | #3 | |
I really should get out more.......
MG ZT-T, Rover 75 Tourer Join Date: Mar 2011
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Quote:
If the reflected power reading is that high then you have a serious mismatch. |
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11th June 2020, 18:15 | #4 |
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Rover 75 Diesel Tourer, called Perseverance Join Date: Nov 2011
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There is a strong suspicion of an aerial mismatch.
But the meter infers that the reflected power is HIGHER than the forward power. Is that possible ? |
11th June 2020, 18:22 | #5 |
I really should get out more.......
MG ZT-T, Rover 75 Tourer Join Date: Mar 2011
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I presume its VHF marine band (156Mhz) and you have a suitable aerial, what type of SWR meter are you using?
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11th June 2020, 18:51 | #6 |
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Rover 75 Diesel Tourer, called Perseverance Join Date: Nov 2011
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It is a marine band aerial, on top of a mast.
The SWR meter is a Alan K155, which I believe is rated for the frequency, and 100W rated. |
11th June 2020, 19:02 | #7 | |
I really should get out more.......
MG ZT-T, Rover 75 Tourer Join Date: Mar 2011
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Quote:
Look at the Diamond SX200 or 400, this will do you. Last edited by Phil-T4; 12th June 2020 at 05:59.. |
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