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I haven't modeled a rototiller yet but I suspect it will have the same problem as Circularly Polarized beams have (at CB frequency). The ground increases the gain of the horizontal component dramatically more than the vertical component making the signal more elliptical than circular.. The...

A horizontal dipole at one quarter wave above moderate (default ground in 4nec2) shows -5 dBi at 8 degrees and 2.1 at 22 degrees. Consider mobiles that get much less than unity gain and far from favorable TOA but still work DX. Not optimal but it can work.

Doubling the power wont increase the received signal like an antennas gain does. It just gives you a bigger mouth than ears.

Take off angle is no myth No, it's a fact . Keep in mind this is a CB /11 meter antenna thread. On 11 meters the signal wont arrive at high angles I posted this before herebut it must have been missed so I'll repeat it Critical angle is directly related to critical frequency...

perfect ground? 8 dBi ?(looks like 7.87 to me) Could be because astroplane is a little directional. Perfect ground inflates gain and hides the take off angle. I have a dipole model at tip height of 36.25 ft , perfect ground gives it a gain of 8.04 dBi Freespace gives the well known 2.15dBi...

I knew it would be contentious Started this 3 days ago so sorry if it reaches way back. sleep, work, read latest posts, write a couple sentences, repeat. That's a nice program there Shockwave wish I could play with it. I tried to find an easy way of reproducing that very effect (only the...

just my take Hi Marconi, Sorry late response I've been super busy lately. When I first started to try to apply modeling to CB frequency antennas I read a long thread (somewhere ) with a heated debate about this very question. Some regarding it as just a modified j-pole, others claiming an...

I was the respondent who asked where 35 ohms came from. OK so ~35 ohms is from a 1/4 wave with horizontal radials (and perfect ground). I got the numbers ( the 70 ohms) from a model with 379 wires and 690+ segments very much like Marconis blazer model only car shaped and the whip is mounted...

That would be where the Imaginary part (the reactance) is 0 Then 35 ohms is from the assumption that a car body most closely resembles a flat ground plane? Don't think I ever thought that let alone hinted at or stated it. But it doesn't matter 35 or 70 either way it's a swr of ~1.4-1.3 so...

So a 105 inch whip @ 27.18 MHz will be resonant at ~ 35 ohms not 70 ohms? Cause I quoted a resonance point (well close to resonance) not just a SWR. Element length =104.88 Impedance = 71.8 +j0.18 Would a starduster type antenna count as a 1/4 wave? What about a dipoe same question?

RE: http://www.k0bg.com Not every thing. The following statement is not factual for 10 -12 meter where it is possible to get a 1/4 wave on a vehicle. And this is a CB question. I'm surre it's true on 40 meters and lower frequencies. The original article even said with the exception of 10 and...

Thanks for pointing out the stupidest rule regarding CBs ever made. Tell me, how am I to know how far away the contact just made is until I've made the contact to find out their 20 ? Assuming they are truthful. I could then refer to my hi res map (HA HA) with the big circle denoting the no...

According to times microwave you can bend as tight as 1 inch radius turns but you cant adjust or bend it again 4 inch radius bends as beetle suggested can be unwound and reworked. So if you bend tighter than 4 inch radius loops you should consider them permanently bent...

Yes reflected CP signals reverse with each reflection. so local would require both left or both right handed ends of the link. Dx would require one left and one right. I saw somewhere that linear signals are converted by the ionosphere to a more elliptical. Which direction the spin was...

Take off angle proven real Actually I was hoping to copy off someone else and not have to do the home work. But I've done it now. You guys can copy mine now instead. <gotproof> Critical angle is directly related to critical frequency. Critical frequency can be found in "near real time"...

OK you may all consider this a fools quest. And it may well be but it's mine. I'm working on the design (model) of a 4 element circularly polarized electrically steered phased array antenna. I'm aware of the article denouncing circular polarization by Tom the author of the take off angle...

Thanks to all who responded . I can tell by the replies that I misused the term MUF and should have used "critical frequency" instead of max useable frequency. So yes I know it's possible to make skywave contacts on the CB band with other parts of the world. So my question should have been...

Not always a myth? I was aware of the thread (in Amateur Radio Antennas) That's why I opened a new thread here in CB antennas instead of posting to that thread. Is the Myth of take off angle article relevant to the narrow band of CB ? Does MUF ever approach 27 MHz? Don't get me wrong I'm in...

Does anyone know the optimum take off angle for CB? Or the most optimistic critical angle.