Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [swr-meter]

Equipment which measures standing wave ratio (SWR). See also [antenna-analyzer]. For questions about fixing “high SWR” problems, see [impedance-matching] instead.

A SWR meter is placed inline in a feed line to measure the standing wave ratio (SWR). It may be a separate unit or integrated in a transceiver. SWR meters often measure power as well; the “crossed needle” SWR meter displays forward and reflected power directly and the user reads SWR from the point of intersection of the needles.

Devices which produce their own test signal, and often measure more parameters than SWR, are s.

For questions about fixing “high SWR” problems, see instead.

38 questions
18
votes
1 answer

How does an SWR meter really work?

For ham radio operators, the SWR meter is a ubiquitous piece of equipment. There are dozens of standalone models on the market and most modern transceivers and antenna tuners have this functionality built in. Any ham with an interest in antennas has…
Glenn W9IQ
  • 18,498
  • 1
  • 22
  • 54
13
votes
5 answers

Is an antenna analyzer necessary for building antennas?

I'd like to try my hand at building a few antennas for VHF/UHF use. I'm going to be going approximately from established designs, but obviously the final result will require some tuning. I don't currently own either an SWR meter or antenna…
David KF4MDV
  • 486
  • 1
  • 4
  • 12
10
votes
3 answers

Why is my diplexer such a spectacular failure?

I'm trying to create a diplexer for the 2m and 70cm bands so that two antennas can share a feedline to my "shack". My radio is a Yaesu FT60 handheld, 5W max. I have home made a j-pole for 2m, and a neat little ground plane antenna for 70cm, both of…
user14945
10
votes
2 answers

How can I calibrate a SWR meter?

I would like to build my own HF (1.8 - 30 MHz) SWR meter, however I'm not sure how I can calibrate the meter without an accurate power source. I'm targeting a power capacity of 150 W so I can use it with my HF radio. However, my test equipment at…
W5VO
  • 1,901
  • 1
  • 13
  • 24
10
votes
5 answers

How did hams manage to tune their antennas before VSWR meters?

In the early 20th century --back when the hobby was still new-- before VSWR meters and antenna analyzers were invented, how did radio operators know whether they were tuned for maximum power out? This is not asking about antenna tuner design or…
Mike Waters
  • 7,843
  • 4
  • 16
  • 50
8
votes
1 answer

SWR Measured at the Transmitter versus SWR at the Antenna

It is fairly well understood that due to transmission line losses, the SWR as measured at the transmitter will be less than the SWR at the antenna. Some of the new antenna analyzers and some vector network analyzers can 'zero out' or compensate for…
Glenn W9IQ
  • 18,498
  • 1
  • 22
  • 54
8
votes
2 answers

What is the point of a SWR/power meter where the needles cross over each other?

There are SWR/power meters with two separate gauges, and others that have them mounted so the gauge needles cross over each other. Aside from looking cool, does the cross-over point of the two meters provide specific or useful information?
Adam Davis
  • 12,095
  • 2
  • 45
  • 106
8
votes
1 answer

Do I need a SWR meter for a basic 2 meter antenna?

I have a 5 watt 2 meter handheld transceiver and want to build a helmet with an antenna, microphone (with VOX enabled) and earpiece for the radio. For the antenna part, I just want to do something simple like a wire at the right length. I'm 15 and…
Skyler 440
  • 7,550
  • 7
  • 48
  • 88
7
votes
1 answer

Can I touch the ground of a PWR/SWR meter?

I'm planning to build a 5W PWR/SWR meter very similar to this design by G3YMC, but with two meters: I'd like to put it in this metal box, and use the box as ground. However, the bottom of the box would then also be ground, and I may accidentally…
user885
6
votes
3 answers

How should this SWR meter's directional coupler work?

I'm wrapping up a "home build" of the MFJ-941EK antenna tuner kit and having trouble getting the wattmeter calibrated. I can't use C4 to get the reflected power reading calibrated down to 0 as is supposed to happen. So now I need to figure out what…
natevw - AF7TB
  • 7,219
  • 2
  • 23
  • 58
6
votes
2 answers

Do I need a separate SWR meter if the transceiver has one built-in?

I'm going to buy Yaesu FT-891 as my first transceiver. I know that I can measure SWR with it if I use FM mode and minimum power, which is 5W for this transceiver. However, I don't know whether it's always safe. For instance, if I connect a…
Aleksander Alekseev - R2AUK
  • 4,262
  • 12
  • 48
6
votes
2 answers

Powering transceiver and SWR/power meter from same supply?

I'm mostly sure this will be ok, but I'd like to confirm. I have a switching power supply (can't remember the model right now, but it's for ham use, 13.8V/30A) and I'd like to power both the FT-857D as well as the power/SWR meter from it. Is there…
Rimio
  • 137
  • 5
5
votes
1 answer

Do External Signals Affect Antenna S11/SWR Measurement?

Do external signals affect the S11/SWR measurement of an antenna? For example, if I try measuring the S11/SWR of an HF antenna with a SWR meter or a Vector Network Analyzer in the middle of a field day with many transmitters near the antenna, or try…
比尔盖子
  • 569
  • 2
  • 16
5
votes
2 answers

RF Bridge Problem - K6BEZ Antenna Analyzer

This question regards erroneous SWR measurements of K6BEZ antenna analyzer (links gone from Internet now) design from 2013 using Arduino and AD9850 DDS modules. There have been many variations of it by other people over the years. Good details to…
Peter Buxton
  • 385
  • 2
  • 13
5
votes
2 answers

What additional information do I get from an RF ammeter, as compared to a regular SWR/wattmeter?

I've grown up using SWR/power meters. They're "simple" devices: They show forward and reverse power, and show the standing wave ratio. They, however, do not show antenna efficiency. New hams are traditionally instructed to tune their antennas so as…
AndrejaKo
  • 2,853
  • 2
  • 17
  • 31
1
2 3