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TROUBLESHOOTING WORKSHOP

SWR too high?

Separate measurement setup, cable and antenna before changing antenna length.

Switch the transmitter off before working on the RF path. Never connect a VNA to a transmitting output. Consult each device’s manual for permitted power and SWR limits.

YOUR NEXT USEFUL TEST

Resolve the visible issue first

A known mechanical problem makes further transmit measurements unhelpful.

  1. Keep the transmitter off. Properly inspect or replace a faulty adapter, damaged cable or uncertain connection; do not ignore moisture by continuing to operate.
  2. A resistance reading alone cannot assess every antenna: some designs intentionally present a low DC resistance. Consider the design and manufacturer’s documentation.

What to look for next

After repair, restart with a verified measurement setup; appearance alone does not establish good SWR.

Related learning & practice

Technical sources for this check

Background and model-specific guidance; the check sequence is editorial. Match menu names against your own model’s manual.

Show check record
HB3YAQ · Check record: SWR too high?
Your answers; no automatic measurement.

1. Do cable, connectors and antenna connection look sound?
→ No, or a connection is unclear

Resolve the visible issue first
A known mechanical problem makes further transmit measurements unhelpful.
1. Keep the transmitter off. Properly inspect or replace a faulty adapter, damaged cable or uncertain connection; do not ignore moisture by continuing to operate.
2. A resistance reading alone cannot assess every antenna: some designs intentionally present a low DC resistance. Consider the design and manufacturer’s documentation.
After repair, restart with a verified measurement setup; appearance alone does not establish good SWR.

ARRL · Feed lines: https://www.arrl.org/feed-lines
ARRL / Darrin Walraven · Understanding SWR by Example: https://www.arrl.org/files/file/Technology/tis/info/pdf/q1106037.pdf

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