SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/ham-relay-switch

What is a relay?

An electrically-controlled switch.

  1. A current-controlled amplifier
  2. A pass transistor
  3. An electrically-controlled switch ✔

Why: A relay uses a small current through a coil to move a switch, so one circuit can turn another circuit on or off.

Huh, didn't know that: Some VHF power amplifiers have an SSB or CW-FM switch that sets the amp for proper operation in that mode.

The dad joke
Why was the relay great at track meets? It always passed the signal along.
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Sources

  1. NCVEC 2026-2030 Technician Question Pool (Feb 19, 2026 release) https://www.ncvec.org/downloads/2026-2030%20Technician%20Pool%20and%20Syllabus%20Public%20Release%20Feb%2019%202026.pdf

Test yourself in the game

Ham RadioWhat type of component is often used as an adjustable volume control?Ham RadioWhat electrical component stores energy in an electric field?Ham RadioWhich battery chemistry is NOT rechargeable?

That's stuff everyone should know.