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.

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7
votes
3answers
796 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 ...
4
votes
0answers
101 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 ...
1
vote
1answer
124 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 ...
5
votes
1answer
61 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 ...
5
votes
3answers
515 views

RF Bridge Problem - K6BEZ Antenna Analyzer

This question regards erroneous SWR measurements of K6BEZ antenna analyzer design from 2013 using Arduino and AD9850 DDS modules. There have been many variations of it by other people over the years. ...
1
vote
3answers
162 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 ...
2
votes
1answer
162 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 ...
1
vote
2answers
60 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 ...
1
vote
1answer
106 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 ...
1
vote
1answer
65 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 ...
5
votes
2answers
271 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 ...
1
vote
2answers
175 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 ...
5
votes
2answers
931 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 ...
1
vote
1answer
290 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 ...
2
votes
2answers
309 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?
10
votes
5answers
769 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? ...
4
votes
4answers
1k 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 ...
5
votes
1answer
91 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 ...
3
votes
1answer
467 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 ...
2
votes
2answers
579 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 ...
17
votes
1answer
3k 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 ...
8
votes
1answer
292 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 ...
1
vote
2answers
271 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 ...
6
votes
3answers
4k 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 ...
2
votes
1answer
702 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 ...
6
votes
1answer
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 ...
10
votes
4answers
9k 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 ...
9
votes
2answers
5k 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 ...
8
votes
2answers
992 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 ...
8
votes
1answer
732 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 ...