take off angle

[Captain Kilowatt]

That would only happen if the station you were working was also using CP since a linear polarized signal has no direction of rotation. On the other hand you do have me wondering about something now. If both DX stations are running CP in the right hand mode, I suspect a refraction on the ionosphere could reverse the direction of rotation. Am I right on this?

Yeah it happens a lot on VHF/UHF communications via satellite or EME. A left hand CP signal reflected off the moon returns as right hand CP and some satellites spin at a high rate which has the effect of producing CP from a linearly polarized antenna.

 

[Marconi]

Last fall I experimented with a PDL-II in the CP mode. I can say it definitely stabilized DX signals. Being that it was only a 5 foot boom the gain was not impressive but this fall I'm working on 8 crossed elements on a 18 foot boom that should give more gain.

If DX causes significant rotation of linear polarized signals it may be possible that mixed polarity of vertical and horizontal would be more beneficial than CP since rotation would be reduced and you could only be 45 degrees away at most from any polarization. Not enough to cause a large drop in signal.

Donald, I don't know if CP has any advantage without other stations also having CP and in the right phase or circular direction.

Do you remember the two guys, both truck drivers, up in the Northwest somewhere that made an sold a big quad antenna they called the Sky King? I think their names were Ted and Bill, but I forgot their numbers.

Bill visited me one time while he was in Houston waiting on a load, and he told me some real stories about their Quad, and the mobile antenna they both used that talked just about as good as their base.

He said their antenna was designed to split the polarities, and whether it did or did not do that...they were some talking antennas that were scattered all about the Nation, with several in the South and Southeast.

I don't think there was any magic business and Bill didn't suggest same...he just said the antennas worked really well, and suggested that any effective yagi could benefit from the same configuration idea.

I had a buddy that use to have a homemade 3 element yagi on a 70' foot tilt over tower in Bridge City, Louisiana, about 350 miles away from Houston. It had both an elevation and Azimuth rotor on it, and back in the early 90's he would talk with that thing pointed over here just about any time he wanted, even to mobiles. He told me once at a CB break, that his antenna worked best when he set his Azimuth rotor to 45* degrees and I believed the man...I had heard him talk.

So, I think you might be right in light of these testimonies...you may find splitting the polarities to be more effective than CP could ever be. I have a KenPro A/E rotor with controller and it works fine. I had it on my home made horizontal 4 element yagi with a moon raker boom, but I could not get it to angle down but about 30* degrees and I would hit my guy lines. This rig was installed on a flat 20' x 20' roof deck that I could tilt over, and I could not handle more than a 10' foot mast with all that load out on the end of the mast.

So, I never had the chance to really test the idea. I could not explain what was happening, but it was responsive sometimes to a slight tilt...I can easily remember that.

I understand he went on into ham operations in a big way with DX operations I think, and has a big antenna farm over there near the actual bridge in Bridge City, La.

I have since lost site of Ole Bridge City George...as we use to call him. He is a great guy if you ever get a chance to talk to him.

This thread is way out of my league, so I started one similar with the idea of TOA's. It is instead, showing an array of my CB antenna models, noting the patterns primarily with the images of the antennas attached. I was thinking maybe the CB guy's would not be so overwhelmed by all the tech stuff, math, and ideas. http://www.worldwidedx.com/cb-antennas/158801-take-off-patterns-cb-antennas-we-use.html

Good luck with your project, and keep us posted.

 

[Shockwave]

CP certainly can be a benefit when working a linear polarized station through DX since a CP antenna will have equal response to signals in any linear polarization. It's only when the other station is operating CP that we have to pay attention to direction of rotation.

With respect to mechanical beam tilt, it's never going to happen on HF. This is very easy to confirm in EZNEC. You don't even have to make the boom. Just place your elements at different heights to simulate the beam tilt and you'll see this is useless.

Even with a 45 degree mechanical tilt, you can't change the TOA by a single degree unless you're in free space without the ground reflection or on a much higher frequency.

 

[Marconi]

CP certainly can be a benefit when working a linear polarized station through DX since a CP antenna will have equal response to signals in any linear polarization. It's only when the other station is operating CP that we have to pay attention to direction of rotation.

With respect to mechanical beam tilt, it's never going to happen on HF. This is very easy to confirm in EZNEC. You don't even have to make the boom. Just place your elements at different heights to simulate the beam tilt and you'll see this is useless.

Even with a 45 degree mechanical tilt, you can't change the TOA by a single degree unless you're in free space without the ground reflection or on a much higher frequency.

Lordie me Donald, me thinks you have misunderstood the idea here, and it is probably my words that get in the way. I gota' get out here and leave this stuff to you young bucks.

Here is the best I can do on short notice trying to explain how an Azimuth rotor works.

Repair Homebrew AZ/EL Rotor Controller - YouTube

 

[Captain Kilowatt]

You both made a mistake. An azimuth rotator swings left and right through the compass points. An ELEVATION rotator tilts the antennas up and down. Marconi that video shows an ELEVATION rotator tilting the antennas up and down. In the video it looks like a screw drive elevation control arm from a satellite dish. Shockwave was right about not being able to effect TOA by tilting the antenna up or down on HF. It just does not work that way. VHF/UHF is a different matter.

 

[Shockwave]

Thank you for the correction CK. Sometimes I get the Azimuth and Elevation confused. Same problem with circumference and diameter. I know what I'm talking about but it's harder to get others to follow when I pick the wrong words.

Marconi, I think Motor Mouth Maul and some others have seen EME antennas like the one in your video and mistakenly thought the same thing would be benificial on HF. I even seen some people purposely bend the mast in an attempt to provide mechanical beam tilt.

 

[Marconi]

You both made a mistake. An azimuth rotator swings left and right through the compass points. An ELEVATION rotator tilts the antennas up and down. Marconi that video shows an ELEVATION rotator tilting the antennas up and down. In the video it looks like a screw drive elevation control arm from a satellite dish. Shockwave was right about not being able to effect TOA by tilting the antenna up or down on HF. It just does not work that way. VHF/UHF is a different matter.

I agree CK, I got this wrong, but I think my point is still confusing. So, I did a video demo to show how I see the Sky King idea working to turn the boom and the feed point into a position that, according to the Sky King manufacturer. splits the polarizations 60H/40V.

This is not my idea...this is my recounting what these guys use to claim about their Sky King 4 and 5 element Quad antenna.

http://youtu.be/KWeHBINRGyQ

 

[Marconi]

Here is a better picture of a Yaesu Azimuth/Elevation rotor that is similar to my KenPro. If you put the boom for a single polarity beam, or a single polarity Quad in the top part of this rotator...then you can rotate the antenna N, S, E, W, you can rotate the feed point up and down from horizontal to vertical using a single feed line, or you can place the feed point at any other angle in between and split the polarities.

 

[dksac2]

CB is made for groundwave, it's illegal to shoot skip with CB, but most CBer's could care less about the FCC rules. My apologies to those who do it right.
So you really don't need to worry about take off angle. Just put your antenna up to legal height and use good coax such as LMR-400 and you will maximize your transmissions on groundwave.
John KF7VXA

 

[Lil'Yeshua]

There's short skip I've experienced before and I can talk up to 153 and so much miles on 4 watts.

 

[ghz24]

CB is made for groundwave, it's illegal to shoot skip with CB, but most CBer's could care less about the FCC rules. My apologies to those who do it right.
So you really don't need to worry about take off angle. Just put your antenna up to legal height and use good coax such as LMR-400 and you will maximize your transmissions on groundwave.
John KF7VXA

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 contacts beyond this point line and find out if I can legally talk them.

Perhaps you could point out the difference between talking to local yocal 2 blocks down and talking to "distant contact". If the conditions are good the signal gets to "distant contact" even if I only was trying to talk to local yocal. Radio waves aren't affected by my intentions or FCC rules just physics.

CB was made for ground wave?
I'm guessing you mean intended for ground wave?
The ham 10 and 12 meter bands were they made for groundwave as well?
Cause this (take off angle) is pertinent to 10 and 12 meter bands also.

While some "CBer's could care less about the FCC rules" I respect the rules that protect the public right to use this resource and protect others use of the EM spectrum.
As it happens I don't freeband and my radio is type certified and unaltered
my present antenna and the design I'm working on are both within the legal limits of FCC rules.


I'll admit to attempting to design an antenna with enhanced capabilities to break that rule.

I guess I'll just have to chance it that the FCC will be to busy with the golden screwdriver, limiter clipping, linear happy and super whack pack swing bleed over kit running crowd to be bothered with a barefoot DXer.

I might have to "get my ticket" and use 10 meter to test out my franken-tenna but for now I don't fill out logbooks unless you pay me.

 

[Captain Kilowatt]

Since we are being picky I feel compelled to point out that groundwave propagation does not exist on 11m CB frequencies. It only exists below about 3 MHz. The term groundwave gets used all the time to describe propagation without ionospheric enhancements when in fact it is actually direct wave propagation. Lime I said, since we are being picky.

 

[Lil'Yeshua]

If you knowingly try to communicate over that many miles assuming that people are still honest and choose to obey the law. I think that law is there as a tool for the FCC to use at their discretion. O don't use the word,'DX' in my CB calling language. Now if we can just get some laws changed about 11 Meter use them I could have fun talking skip.

 

[Grinder74]

I bet that hambone never broke a speed limit or ran a red light. Come on, who did I hurt taking to Jack Crap in St. Louis! If I was worried about TOA I would get a beam and be done.
Oh and don't forget hammy, 11 meter was originally a ham band! HAha!

 

[Lil'Yeshua]

WE THE PEOPLE

The thing is that we've had almost eighty years to refine the use on 11 meters. I think that it's time to change some laws. After all,we're supposed to be a self governing nation,right?! Let's not allow power hungry egotistical dillusioned people who get in an office to use that as a bludgeoning tool anymore to lord it over us anymore. All it takes is a movement with enough momentum and persistence and intensity to change certain laws. After all,they work for us.
WE THE PEOPLE.....