Linked Questions
34 questions linked to/from How to detect common-mode currents or “RF in the shack”?
2
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SWR, overall, is too high
This is a sort of follow-on question from my tuners in series question.
The problem I am ultimately trying to solve is this:
I am using a manufactured end-fed, half-wave 40m antenna. The ...
- 103
6
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2
answers
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How to measure a balun for effectiveness?
It seems there are almost as many "balun" designs as there are web pages about "baluns". There's lots of accusations pointed in all directions ("design Z isn't a balun OR a choke", "design Y is ...
- 7,411
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High 40m noise floor during the evening but quiet in the afternoon
I've been dealing with S7 static on 40 meters ever since I got started a few weeks ago. It's so bad that I have to use my RF ATT so that the static is not deafening.
I did some research about ...
- 781
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4
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Which is better in my situation: Balanced dipole, or as much wire as possible in the air?
I'm finally getting to the point of hopefully putting up a HF antenna. The idea is to start with a simple, straight wire dipole using trees as support points. (No traps or coils.)
However, with the ...
- 4,878
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2
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Does effective grounding of mobile (vehicle) antenna mounts address common-mode currents?
While researching how best to install my mobile amateur radio in my car, I didn't understand
if there was optimum Antenna Feedline Length for mobile installations?
Understanding that this is caused ...
- 681
2
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3
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What does it mean to have "RF in your signal"?
I've been told that I have "RF in my signal". What does this mean? What are some potential causes of having RF in the signal?
- 121
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2
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859
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2 meter coax cable balun dimensions for use with a ground plane?
I have a commercially manufactured ground plane antenna for 2 meters. It will be fed with about 150 feet of RG 8/U . I've seen pictures of a coil of the feed line going to a 2 meter ground plane; this ...
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4
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2
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Dipole increased CM current using choke balun
My 20 meter inverted vee dipole is fed with 56 feet of 50-ohm coax. The SWR measures 1.2 at the center of the band. According to http://arrl.org/grounding a balanced antenna doesn't need a ground, so ...
- 385
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2
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565
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Loop Antenna Construction
I have a loop antenna.
When I connect the probe from my oscilloscope, does the probe also act as an antenna? If so, how should I fix that? I read about feeding technique, but I still do not ...
- 129
1
vote
2
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636
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Troubleshooting 5BTV antenna
I have a Hustler 5BTV antenna i resurrected after a previous monopole succumbed to birds.
It is giving me a world of trouble trying to get it tuned for resonance.
For those not familiar with the ...
- 697
1
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2
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Multi-part question. correct length of rg-8x coax to connect 2 meter HT to 50 ohm yagi
What it the optimal number of wave lengths of RG-8X coax to connect my Icom IC V80 HT to a 50 ohm Jetstream JTBM270 Yagi (3 elements 2m/5 elements 70cm)? Odd or even number thereof?
Will running the ...
3
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2
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269
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Interpreting (noise) signals from a small untuned shielded loop
This a follow up from this question:
QRN: How to chase down a solid S9 noise floor on 40m only
Focusing on how to interpret the signals received with an electrically small, untuned "shielded loop&...
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3
votes
1
answer
514
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How can I tell the frequency without an oscilloscope, or frequency counter?
Just going through the RF oscillator listed on SM0VPO's web-site. I replaced C1 by a reverse biased 6A8, and used an E-core transformer pulled out of a Compact Fluorescent Lamp instead of an inductor ...
- 2,834
1
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1
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How to assemble an antenna (impedance matching methods)
I got the following plans off Martin E. Meserve's website.
How do I go about assembling the antenna once I have the elements and boom? What is the impedance of the driven element? Do I need baluns ...
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2
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Using a common-mode choke on symmetrical antenna system
I am curious as to what happens to a symmetrical dipole center-fed with balanced feeder-line. Let's assume the dipole is arranged as a sloper - that means it's not parallel to ground (horizontal). ...
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