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.

It could be it is a real reading and you have a fault in the antenna system.

Do you have a license to operate marine band?

If the reflected power reading is that high then you have a serious mismatch.

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 ?

I presume its VHF marine band (156Mhz) and you have a suitable aerial, what type of SWR meter are you using?

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.

No, that is not suitable for the VHF marine band, maximum for that meter is 150Mhz but was more commonly sold as a CB SWR meter.

Look at the Diamond SX200 or 400, this will do you.