Skip to main content

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.

Filter by
Sorted by
Tagged with
18 votes
1 answer
6k views

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 ...
Glenn W9IQ's user avatar
  • 18.6k
13 votes
5 answers
11k views

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 ...
David KF4MDV's user avatar
10 votes
5 answers
2k views

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? ...
Mike Waters's user avatar
  • 8,071
10 votes
3 answers
1k views

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 ...
user avatar
10 votes
2 answers
7k views

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 ...
W5VO's user avatar
  • 1,901
9 votes
2 answers
686 views

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 ...
Glenn W9IQ's user avatar
  • 18.6k
8 votes
2 answers
1k views

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 ...
Adam Davis's user avatar
  • 12.2k
8 votes
1 answer
1k views

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 ...
Skyler 440's user avatar
  • 7,620
7 votes
1 answer
1k views

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 ...
user avatar
6 votes
2 answers
4k views

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 ...
Aleksander Alekseev - R2AUK's user avatar
6 votes
2 answers
254 views

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 ...
Rimio's user avatar
  • 137
6 votes
3 answers
8k views

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 ...
natevw - AF7TB's user avatar
5 votes
2 answers
2k views

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 ...
Peter Buxton's user avatar
5 votes
1 answer
110 views

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 ...
比尔盖子's user avatar
5 votes
2 answers
654 views

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 ...
AndrejaKo's user avatar
  • 2,893
4 votes
4 answers
3k views

Can a CB SWR meter be used for HF amateur bands?

I have a basic CB SWR meter, I can’t see any reason why it can’t be used on other HF bands and be at least indicative of what the SWR is, even if the absolute power measurement is inaccurate. Is this ...
MattC's user avatar
  • 87
4 votes
1 answer
177 views

Looking for criticisms on my VNA-like SWR meter I am designing

I am in the process of building a SWR meter with VNA-like features. I'd be really interested to hear from fellow hams any input, suggestions, or tips they have regarding this before I go get it mass ...
Jeffrey Phillips Freeman's user avatar
4 votes
0 answers
186 views

Problem with theory of HF detector

I'm currently trying to build my own SWR power Meter. This design is based on the so known HT detector with schottky diode BAS70. For my understanding, and for easy purpose, I'm currently focusing on ...
F4BJH's user avatar
  • 61
3 votes
1 answer
170 views

Do you need to analyse the SWR of your radio repeatedly? Or periodically? If so, Why?

Let us assume that I have an adjustable antenna, between 160m - 6m. And let's also assume that using an antenna analyser I have estimated the SWR for that antenna for a specific frequency. If my ...
Bartha's user avatar
  • 169
3 votes
1 answer
1k views

Am I calibrating my SWR meter, SWR-001, correctly?

I have an SWR-001, which seems to be released under two different brands, MyDEL and Sharman. The MyDEL SWR-001 looks like this: and the Sharman one looks the same except for the label on the bottom ...
Pablo Fernandez's user avatar
3 votes
1 answer
160 views

Low power indicated on tuner

Please forgive my extremely basic question, I am brand new on HF and have issues with my setup. I have a Chameleon MPAS antenna in vertical configuration connected to an AT-100 ProII tuner with a 50 ...
kataik's user avatar
  • 133
3 votes
1 answer
274 views

Can you think of any reason my NanoVNA says my antenna has 1.2 SWR while my radio says it has off the scale SWR?

My radio is an mcHF kit that I just finished soldering up. It receives fine, but when I went to transmit it's giving off the scale SWR. I rechecked my antenna with my NanoVNA, and it shows 1.2 SWR at ...
rcx935's user avatar
  • 411
2 votes
2 answers
801 views

Lightbulb as an SWR detector?

Back in ye olden days before SWR meters and auto-tuners, how was a ordinary household lightbulb used to help tune an antenna system? What did the circuit and tuning procedure look like?
hotpaw2's user avatar
  • 13.5k
2 votes
2 answers
1k views

What's the difference between a Return Loss Bridge and a Circulator?

From my understanding a return loss bridge basically consists of three terminals: an RF input, a DUT output and a RF output which goes to say a spectrum analyzer; I understand that the RF input signal ...
S.s.'s user avatar
  • 153
2 votes
1 answer
118 views

Snap on choke on coax line leading from radio. Wrapped an LED around the choke and it lights with transmission, but only on certain bands? SWR?

Why does a LED wrapped around a snap-on Choke attached to radio antennae coax only light up when transmitting on certain bands? Is this an indication of high reflected power in the braid inducing ...
Hetzal Hartley's user avatar
2 votes
2 answers
864 views

Do VNA (nano) suffer the same effect of coax length to swr, as swr meters do?

A SWR meter will vary in swr with coax length if unbalanced as your coax length is around 1/2 wave length multiple. Does a VNA ( nanoVna ) in this case experience the same effect, (obviously assuming ...
Hayden Thring's user avatar
2 votes
1 answer
1k views

Why SWR significantly changes with adding 10-30 meters of coax in presence of RFI choke?

I've build a verical for 40M band using a fishing rod as a mast, 6 radials and an RFI choke (FT240-31 ring, 8 turns of RG58, W1JR winding according to the article by Steve Hunt). When I measure SWR ...
Aleksander Alekseev - R2AUK's user avatar
2 votes
1 answer
2k views

Is it possible to determine if I'm adjusting gamma match in correct direction with an SWR meter and if yes, how?

I've recently obtained a Quad Loop antenna for 2 m and 70 cm that's fed through gamma match, as shown in the picture: The shorter metal bars are connected to the hot side of the BNC, while the longer ...
AndrejaKo's user avatar
  • 2,893
2 votes
1 answer
532 views

How to understand same SWR but different Tx/Reflected power

I'm tuning a wire dipole. Cross-needle SWR meter shows the same SWR on the lower end of the band as on the higher end. However, the needles move much higher on the lower end. They cross on the same ...
Alexander's user avatar
  • 321
1 vote
3 answers
575 views

Does the impedance along a transmission line change when there are standing waves?

I know the characteristic impedance can't change because it's determined by the physical properties of a transmission line. But the impedance seen when there are standing waves changes along the ...
Andrew's user avatar
  • 3,693
1 vote
2 answers
664 views

Why some hams test their baluns with an SWR meter?

There are videos on YouTube that show how to make a 1:1 current balun. When the balun is done some people connect a 100W 50 Ohms resistor to the balun and measure SWR say in 7.000-7.200 MHz range. If ...
Aleksander Alekseev - R2AUK's user avatar
1 vote
2 answers
135 views

To which part of the band should I tune my Hi-Q wire antenna if my transceiver has an automatic antenna tuner?

I'm attempting to tune my DX-EE Alpha Delta multi-band wire antenna. The instructions state: The 40 meter sections can be shortened to the SSB section of the band by pulling the wires through the ...
watkipet's user avatar
  • 689
1 vote
2 answers
928 views

ZS6BKW deaf on all bands except 40

I have purchased a high quality ZS6BKW from the U.K. I have it suspended up about 40' between 2 trees. There is 30' of coax from the ladder line to the radio (Kenwood TS-870).SWR on the MFJ269 shows ...
Danny's user avatar
  • 87
1 vote
1 answer
297 views

How to interpret VSWR results for an attic antenna

I have an Alpha Delta DX-EE antenna in my attic. The antenna is 40 ft long and my attic is about 5ft high by 55 ft long. There's a lot of other stuff up there--a chimney, Romex, Cat 6 cable, RG-6 ...
watkipet's user avatar
  • 689
1 vote
2 answers
511 views

Measured forward power less than "usual"

I've just tried making my own J pole antenna. While matching for lowest SWR on the SWR meter, I noticed that my FTM400 didn't show 5 W forward power. I hardly saw the reflected power needle move so I ...
Hans Neve's user avatar
  • 227
1 vote
1 answer
122 views

Really Low SWR Reading On PMR

I spoke to a friend about what antennas I was using for PMR and the frequency range on them was only set to 170-430Mhz he said it could lead to a high SWR, So I decided to test it out for safety ...
T. Jones's user avatar
1 vote
1 answer
847 views

FTDX3000D SWR Meter

I just bought a Yaesu FTDX3000D and would like to see the SWR. Is it possible to display the SWR on the FTDX3000D? If so, what menu option would that be? I'm not finding it. I searched for this ...
K8KV's user avatar
  • 377
0 votes
1 answer
160 views

SWR jumps to maximum of gauge

(I'm asking this in the context of a Cobra 29LTD CB, but I think that it also applies to amateur radio in general.) In SWR mode, the needle swings all the way to the right, hitting the limit. The (mag ...
Galaxy's user avatar
  • 199
0 votes
1 answer
97 views

How to Measure Bandwidth using just your receiver [closed]

How do you measure the two to one bandwidth of an antenna using a Bird Watt meter? Tom Planer KJ9P
Tom Planer's user avatar