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Questions tagged [antenna-tuner]

Questions relating to the setup and use of antenna tuners, the virtues and shortcomings of various types of tuners, etc.

0
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1answer
25 views

Do I need an 9:1 UNUN for a half-wave end fed?

I was using a 10-ish meter wire as my HF rx antenna. That's all I can install in my QTH. However I realised that my ~10 m wire can be turned into an end fed dipole for 20 meter band. But there is a ...
2
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2answers
114 views

Can anyone tell me how to make a 35 m long wire antenna work on 80, 40, 20, 15 and 10 metres?

I have one straight horizontal wire antenna 35 meters (114.83 feet) long. I want to make it work the best on average for the 80, 40, 20 ,15 and 10 meter amateur bands. Can anyone tell me the best ...
3
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1answer
164 views

Benefit to remote antenna tuner for end-fed non-resonant antenna?

Does addition of a remote feed-point antenna tuner affect the use of the coax braid as a radiator? If it no longer "radiates" in such a setup, what does? Is a shack or remote tuner better for ...
2
votes
1answer
74 views

Does an LDG YT-100 automatically trigger a tuning cycle if the SWR is high?

I have a YT-100 connected to my FT-857d in my remote-by-default shack in the attic (i.e. I operate it over a VNC connection from elsewhere in my house). Whenever I change band I have to go up to the ...
1
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2answers
146 views

Rotary Inductor Replacement

I thought it was time to build a balanced-balanced antenna tuner so I mechanically ganged two B&W 3852 rotary inductors to make a balanced L network. It appears that the 16 uH inductors I used ...
2
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2answers
150 views

Using one of two antenna tuners connected in series

I have: A Kenwood TS-590SG. 2 antennas up, a tri-band beam and a fan dipole. I run both antennas to a MFJ-998 auto tuner. I also have a MFJ versa tuner IV. The auto tuner works good for 80-10 meters ...
2
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4answers
581 views

What is an antenna tuner? Why bother with resonant antennas in the first place?

There are a lot of antenna tuners on the market that have various capabilities in terms of how they can allow random radiators to work with our transceivers. What exactly do they do? My ...
4
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1answer
525 views

Is ladder line necessary when using a non-resonant dipole through a tuner?

I've heard if I have a dipole of some arbitrary length, or a random wire, the SWR can be very bad. An antenna tuner can present a decent match to the transmitter, but the SWR on the feedline will be ...
2
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2answers
2k views

Antenna tuner design

In a related question about a broadband antenna for SDR it was suggested me to build or buy an antenna tuner. Since maybe it was not clear to everybody, I'm designing an antenna tuner for reception, ...
7
votes
3answers
415 views

Two Antenna Tuners in Series

My radio has an internal antenna tuner that can be activated to rapidly tune for the frequency in use. My antenna has a disgusting SWR for the band I want to use (as measured with an AA-54 antenna ...
3
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3answers
231 views

How do I set up my radio for an antenna tuner?

I recently acquired an MFJ Versa Tuner II model MFJ-949D as well as a Kenwood TS-430S radio. The instructions for the tuner state (in part): For optimum operation of the MFJ-949D, the transmitter ...
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3answers
615 views

What is the actual loss in a feed line with high SWR?

It is well-known that it is unwise to have standing waves on the feed line between one's antenna and one's transmitter, unless it is a very low-loss type (e.g. ladder line), because the transmitted ...
3
votes
1answer
162 views

Using an HF antenna for VHF scanning

Are there any disadvantages (or advantages) to using a long-wire HF antenna for wide-band VHF reception? Or would feedline losses make that useless compared to a ground level ducky or short whip? (...
2
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2answers
1k views

Balun and tuner configuration for multiband dipole

I'm putting up a multiband dipole in some tall trees. (Perhaps it's more correct to call it a "dipole-doublet"). The situation I'm imagining looks like this: The legs of the antenna are each 100 ...
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2answers
175 views

Tuning an antenna with cold weather

I have a 20m long dipole that starts at 2m above the ground and ends at perhaps 20m above the ground. It was -10 °C here tonight (that's +14 °F), currently around zero (32 °F) and my antenna is out of ...
1
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3answers
830 views

Will an Internal Antenna Tuner work with an external HF amplifier?

I am a new General and don't quite understand how Antenna Tuners work other than changing the impedance ratio between the radio and the antenna. So my question is - Do I need to buy a new tuner if ...
2
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2answers
182 views

Adapting an antenna tuner for use with a panel meter instead of an LED

I'm building NorCal's / W6JJZ's BLT tuner (pdf) for use on 40m/20m with a 5W transmitter. I would like to remove the LED and use a small panel meter instead. I don't have a 1N34A at hand, but I do ...
1
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1answer
518 views

Do a toroid's specs matter much in an antenna matching transformer?

I'm getting started with my first (very basic) HF rig and for convenience and the experience I'd like to try an End Fed Half Wave antenna. Typical designs for a "matchbox" in this case include ...
3
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0answers
885 views

TS-590 Antenna Tuner Protocol

I'm looking for the protocol used by Kenwood's TS-590S antenna tuner port. I've worked as far as I can with Kenwood's tech support. They know what the pins are labeled, but don't have any information ...
3
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2answers
988 views

Where does one find high-voltage variable capacitors and inductors for RF? [closed]

I'm looking to start building various antenna tuning circuits, but I'm limited by my parts inventory. I have pots and mag wire for winding inductors and a nice spectrum of fixed-value capacitors, but ...
0
votes
1answer
172 views

Understanding needed with LDG AT-100Pro

I bought an LDG AT-100Pro via CheapHam. Supported equipment: Yaesu FTDX3000D, ZS6BKW multiband antenna. I bought this as an improvement over the FTDX's internal tuner. The LDG does a great job ...
7
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1answer
363 views

Antenna tuning while receiving

I've built AA5TB's antenna coupler for a 5W 20m transceiver. Tuning was kind of difficult because my transceiver has buttons for sending a dot and a dash, but no tuning mode, so I couldn't have the ...
4
votes
2answers
692 views

Adapting an antenna coupler

I've built AA5TB's antenna coupler: I left out C2 because I didn't understand why I would need it - why would I? It works fine without. Unfortunately, when I started tuning for a 5W 20m transceiver, ...
9
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2answers
964 views

Why is the risk of damage to a transmitter due to a mismatched antenna at lower frequencies greater?

A quick follow-up to this answer ... If the impedance mismatch is large, you risk damaging your radio, particularly on the lower frequencies ... I'm sorry to be so dense, but uh why is the risk ...
4
votes
1answer
494 views

Do vacuum variable capacitors have higher Q than air variable capacitors?

Do vacuum variable capacitors have higher Q than air variable capacitors? They are not commonly seen in tuners or crystal sets. But they are mentioned as superior to air variables for resonating ...
2
votes
1answer
538 views

What range of mismatch can the internal tuner on the TS-480SAT accommodate?

A fellow ham recently acquired a TS-480SAT. His working condition is complemented by an inverted-vee for the 20m band around 10m above ground; solid 59+ reports. Trying to tune the same antenna on ...
9
votes
3answers
321 views

What is the best practice when tuning an antenna on air?

I have a magnetic loop antenna that takes a long time to tune and of course, while tuning it, I need to be transmitting. What is the best procedure for tuning on air? I understand I need to check ...
2
votes
1answer
466 views

Tuning an antenna with a SWR meter that relies on output power

In my (new) setup, I will have a solid-state HF radio driving an antenna through an antenna tuner. Both my radio and the antenna tuner have internal SWR meters, of the type that requires you to adjust ...
13
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12answers
11k views

How can I safely transmit without an antenna tuner or SWR meter?

Just what the title says. An Antenna Tuner, henceforth AT, is almost a de facto piece of equipment in a shack; working the bands without one is tantamount to leaping off the diving board into a ...
6
votes
2answers
739 views

Does a tube based HF transmitter need an antenna tuner?

With the adjustments on a transmitter such as a Yaesu FT-101E, is there any purpose for an antenna tuner, or can you accomplish the same thing by adjusting the loading and other controls?
15
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3answers
6k views

Why do I need to tune an antenna?

I've heard that when an antenna is set up, it needs to be tuned to reduce reflective power back into the radio. Is this always necessary, and if so how would I go about tuning it?