Start here: If touching the radio changes SWR, your body is becoming part of the RF system, which usually indicates common-mode current, an incomplete return path, or unstable measurement geometry.
Why this changes a real station
Your added capacitance and coupling alter current on the chassis, coax exterior, control cables, or nearby conductors. The meter is revealing a system boundary that is not controlled.
What it looks like in practice
A small change can occur in extremely sensitive setups, but a repeatable meaningful shift deserves investigation before adding power.
What to do next
Confirm the documented radiator and return, add the correct feed-point choke, shorten or reroute unintended conductors, and measure again with the station untouched.
Evidence boundary
Keep frequency, reference plane, antenna geometry, losses, measurement method, and safety conditions attached to the conclusion. A match, a DC check, or one field symptom does not prove efficiency or identify the complete RF path.
