SWR AND POWER

[959]

why does the swr go up with the more power you run with the radio ?

 

[W5LZ]

Because that's not what causes the apparent increase in SWR. The meter used to get that SWR reading is 'set' to a particular amount of power, or power level. When the amount of power being fed to the thing is changed and the meter isn't reset, or re-calibrated, then the meter isn't reading correctly anymore and there's no telling what the thing will read.
The only way for SWR (or the impedance matching that SWR indicates) to change is if there's a physical or electrical change in the system the meter is measuring. If you didn't make a change, and if the antenna appears to be 'normal', then the most likely reason for that SWR change is a goof in the measuring of it. And unless there's a drastic change in SWR there's no particular significance to it.
- 'Doc

 

[Captain Kilowatt]

why does the swr go up with the more power you run with the radio ?

It doesn't. You are either not recalibrating the meter to correspond to the higher power or you are spewing waaaay to many harmonics etc that the meter thinks is normal reflected power.