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7 votes
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3 Band (80-40-20 Meter) Fan Dipole Tuning Question

Before getting to the questions you asked, an observation: the design doesn't appear to include a balun. Adding one is probably a good idea. Is there a way to flatten the SWR in this range [80m] or ...
Phil Frost - W8II's user avatar
6 votes

I'm looking for an effective beam antenna for both 20 meters and 10 meters

From some research, beam antennas only seem to come as monoband antennas. Not true — actually 20/15/10m tri-band beams are very popular. Multi-band yagis come in two basic flavors. Trapped. Works on ...
hobbs - KC2G's user avatar
  • 12.5k
6 votes
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Dipole antennas: Will paracord hold up well enough in the sun? Is there a better alternative?

Paracord is a usurped and abused term for a wide variety of cords. The US Military previously specified 6 different types of paracord. It is also known as parachute or 550 cord. Originally constructed ...
Glenn W9IQ's user avatar
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6 votes
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HF Noise Level S5 to S9+18

Some troubleshooting ideas: Check your radio's power supply for noise by substituting a battery and disconnecting the PS from the wall. Run your receiver on a battery and turn off your main breaker. ...
Glenn W9IQ's user avatar
  • 18.6k
5 votes
Accepted

Fan dipole radiation pattern

The Mighty Woof article seems to indicate that those are 1/2WL fan dipoles. Two fan dipoles will interfere if one of the dipoles is resonant on both bands. Unfortunately, 144-148 times three is 432-...
Cecil - W5DXP's user avatar
5 votes
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Modelling a "fan dipole" or "fan inverted vee" using EZNEC - unexpected result

Yes, being limited to 20 total segments for two dipoles is likely to be a problem, especially because of your hope / plan / expectation to have the model accurately predict what is built. I created an ...
Brian K1LI's user avatar
  • 7,878
4 votes

I'm looking for an effective beam antenna for both 20 meters and 10 meters

Engineer999. The driven element of a yagi antenna is normally a half wave dipole, and it's true that a dipole antenna is resonant on multiple harmonically related frequencies. An ideal 10 m long ...
Andrew's user avatar
  • 3,693
3 votes

Is spacing of fan dipoles necessary?

Spacing is absolutely required between the antennas. You cannot bundle all the wires together. They must be spaced apart, or the interaction between them will be too great. You'll have a mostly ...
Mike Waters's user avatar
  • 8,071
3 votes

Is spacing of fan dipoles necessary?

In my experience no need for any spacing at all. I've made 80-10m fan dipoles with ribbon cable. Yes, the wires interact but after tuning I got nice clean resonances on all bands. Start with the ...
pidloop's user avatar
  • 59
3 votes
Accepted

Mutual impedance of two parallel dipole

I think if you're worried about the load on the other dipole, you need to go back and look at how Z parameters work. $Z_{21}$ doesn't assume anything about the impedance on the two dipoles. It's just ...
tomnexus's user avatar
  • 11.4k
3 votes

HF Noise Level S5 to S9+18

Just went through the same thing last year. One hint - does the static level lower when it rains? if the answer is yes, very likely a bad insulator or distribution transformer. Took my electric ...
Dave's user avatar
  • 81
3 votes

Fan dipole radiation pattern

Basically, fan dipoles should have similar patterns, as only one dipole is resonant at a time. However, individual dipoles in any arrangement where they all share a common feedpoint should be spaced ...
Mike Waters's user avatar
  • 8,071
2 votes

Bow Tie antennas impedance

A single bowtie dipole does have an impedance of about 50 ohms. However, stacking multiple dipoles with a properly-designed phasing system can change that. Here's a TV antenna that I made and use, ...
Mike Waters's user avatar
  • 8,071
2 votes

Fan dipole with loading coil(s)?

This is already a commercially available antenna. Alpha-Delta makes several variations, with the DX-LB-Plus being the one I'm using. It covers 10,15, 20, 40, 80 and 160, with loading coils for 80 and ...
Dave's user avatar
  • 81
2 votes

Modelling a "fan dipole" or "fan inverted vee" using EZNEC - unexpected result

I doubt that the segment limits of the program is your main problem. You should get accurate enough details in spite of that. Part of the problem is at the feedpoint. You need to build your fan ...
Mike Waters's user avatar
  • 8,071
2 votes

Is spacing of fan dipoles necessary?

You don't say if you're talking about several dipoles connected together into a single antenna, which is an arrangement usually called a fan dipole, or several nearby dipole antennas that each have ...
rclocher3's user avatar
  • 9,242
2 votes

I'm looking for an effective beam antenna for both 20 meters and 10 meters

A resonant 20 meter monoband Yagi will not work on 10 meters. Have you considered a 3-band 10-15-20 Tri-bander? It is a beam, and definitely not a monobander. There are also smaller tri-band ...
Mike Waters's user avatar
  • 8,071
1 vote

I'm looking for an effective beam antenna for both 20 meters and 10 meters

Dipoles are resonant on odd harmonics of their fundamental frequency. So a dipole resonant on 20 meters, or 14 MHz, is also resonant on 14×3 = 42 MHz, 14×5 = 70 MHz, and so on. 10 meters is (...
Phil Frost - W8II's user avatar
1 vote

Is spacing of fan dipoles necessary?

Spacing of parallel dipoles influences the bandwidth you can achieve on every particular band. The smaller the spacing, the more narrowband antenna becomes. However, there is a trick you can use to ...
Jacek Pawłowski SP3L's user avatar
1 vote

Is spacing of fan dipoles necessary?

Consider this "mind experiment" for a limiting factor in the separation required for "Fan Dipole Radiators". Given a Fan-Dipole for 28MHz and 4MHz. Given a Effective Power Out of ...
Glen Ellis K4KKQ's user avatar
1 vote
Accepted

Half wave dipole with parasitic element, (Gain calculation)

The demo version of EZNEC software (free) would be able to do that, with a fairly short learning curve: https://www.eznec.com/demoinfo.htm
Richard Fry's user avatar
  • 2,922
1 vote

Fan dipole with loading coil(s)?

As an extension to the above answer, which mentioned the commercially available option, there is this calculator to make your own. This covers the necessary inductance of the loading coils. https://...
OrangePeel52's user avatar
1 vote

Dipole antennas: Will paracord hold up well enough in the sun? Is there a better alternative?

It does work well although weather will eventually get to it. I got at least 10 years out of some salvaged from an old chute probably made in the 50s. Used to support a dipole made of #3 wire (some ...
George VE3YV's user avatar
1 vote

HF Noise Level S5 to S9+18

Can you Turn off all the power in your house Plug the radio into a battery source (i.e Car 12V) You only need to Rx so no massive power requirement. Now listen... is this better or the same. As ...
Tim Seed's user avatar
  • 290
1 vote

HF Noise Level S5 to S9+18

You wrote "The power lines are parallel to the dipole " and you allow that to pass "OK" because " the dipole is currently in the only place that I can put it...". In theory , you are inviting ...
Glen Ellis K4KKQ's user avatar

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