Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [impedance]

Impedance is the measure of the opposition that a circuit presents to an alternating current when a voltage is applied. This is a force of much interest to the radio amateur especially surrounding the connection to antennas.

107 questions
5
votes
2 answers

Will measuring SWR through a feed line mislead me?

I know that except in the perfectly matched case, transmission lines transform impedances along their length; if I measure the impedance at the other end of my feed line, or even with a short jumper between my antenna analyzer and the antenna, I…
Kevin Reid AG6YO
  • 24,506
  • 7
  • 51
  • 103
5
votes
1 answer

Measuring Output Impedance of an RF (HF/VHF) Active Circuit with Hobby-level Tools

Is there a simple (by simple, I mean a hobby friendly method that trades some accuracy for expense) method of measuring the "actual" output impedance of an active or "hot" RF (HF to VHF) circuit? As an amateur radio enthusiast, I often find myself…
Buck8pe
  • 989
  • 5
  • 14
2
votes
1 answer

The 'plating material' materials and constants of the constants

The 'plating material' materials and constants of the Single-Layer Helical Round Wire Coil Inductor Calculator appear wired-in. There appears no 'un-plated' option. How to use this calculator to work with un-plated magnet wire?
BlipBertMon
  • 21
  • 1
0
votes
1 answer

Impedances inside transmitter?

A 50 ohm match can be tricky outside a transmitter to match. One has to deal with ensuring the antenna , coax, and all connectors are all equal or close to the output impedance of the radio. Let alone the external connections, is impedance matching…
Skyler 440
  • 7,600
  • 7
  • 49
  • 89
-2
votes
2 answers

The idea that a non resonant antenna cannot accept current as well as a resonant antenna is a myth?

In a youtube video titled "Antenna Engineer Vs Ham Radio Myths! True or False?" the guy says this in the comments: The idea that a non resonant antenna cannot accept current as well as a resonant antenna is a myth. Of course you have to use a…
K3ZD
  • 1
-3
votes
0 answers

Reflected power does not flow back into the transmitter and cause damage!

Anyone who knows anything about ham knows the following statement to be true: Reflected power does not flow back into the transmitter and cause damage. However, there is this guy that claims he blew up his rig transmitting without an antenna,…
K3ZD
  • 1