Base First beam

[SuperLid]

Personally, I would go with a yagi type all day long. BUT, this would mean a free standing tower and lots of money, plus lots of labor that this old body doesn't have much of. So, I'm wanting to put the rooftop tower on a shed, but the shed is rather close to some trees and a power line about 15+ feet away. A 3 or 4 element yagi has two major drawbacks. The length/turning radius, or the height and length if mounted vertically, thinking the mast may interfere with the operation. I need something short and directional that will give me better performance than a ground plane or there's no sense in changing. Even at 5 or 6 dBd I'd be getting much better performance than a GP. For the cost, I'm fine with that. Add the rear end rejection and it's a plus. Wish I'd done this 30 years ago when I had a body left so I could use a 40' tower and climb it. But, it is what it is. More than likely, I wouldn't be using the flat side anyway. I would install it in the vertical polarization since the vast majority of folks are et up that way.

Hey Greg! Have a look at the "HENTENNA". Sounds like what you are dreaming about. I have yet to make one yet. It is on my list of future projects. I hope you build it and report back. I don't see anyone talking about this antenna on here. I bet this gets a lot of banter.

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://hb9sota.ch/wp-content/uploads/2015/07/The-Hentenna-Pr%25C3%25A4sentation_EN-HAM16.pdf&ved=2ahUKEwjL9Mf63puMAxURM1kFHZ9uAgQQFnoECA8QAQ&usg=AOvVaw3dMv55a0f2y9oDKfH_mPS5

SuperLid

 

[unit_399]

Greg T -
I agree with Crawdad. I believe the V-Quad is your best bet. Especially considerating where you're mounting it and space limitations. Don't get all wound up in the gain specs. For what it is, size-wise, it will give you the best bang for the buck. Use a steel (NOT aluminum) mast for best wind resistance. A good thing about the V-Quad is that the entire antenna is above the mast, eliminating the pattern distortion caused by the mast with other antenna designs. Good luck. Let us know how things work out. 73 Mi Amigo.

- J.J.

 

[BJ radionut]

CB Series – CUBEX QUADS- Welcome Cubex Quads

www.cubexquads.com

 

[BJ radionut]

The V-Quad is just IMHO a very off balanced center of gravity mounted antenna...wind load issues are created when mounted with V-up designs...never seen one mounted in the up position stay they're long at least not in Mid-West weather...Diamond quad style can handle the wind/Ice much longer.

 

[BJ radionut]

Not sure this will load...The Master of the Quad/Bill Orr.

 

[Greg T]

Thanks for all the replies and excellent info, guys! I have a lot of reading and studying to do before summer so I can decide on the best fit for my application. This would all be so simple if I had a 50' free-stander and a bucket truck~! But, such as it is, I have to make due. So far, looks like a two element or V quad will be the front runners, unless I can trim enough of the trees back to make more room. Don't know about that yet. The info and responses are much appreciated!

 

[Henry HPSD]

The length/turning radius, or the height and length if mounted vertically, thinking the mast may interfere with the operation. I need something short and directional

I would not rule out the 2el Cubical Quad BJ mentioned...

You have stated you would like "vertical" polarisation, and better results then your present vertical.

That means the delta loop has to be on the flat side in alsmost a "<" shape.
( One leg needs to be horizontal.)

One of your primairy reason to think about the 2el Delta loop was its turning radius.

If the antenna is configurated to work vertical, the turning diameter will be well over 7 meters... say 25 feet.. this is a lot more then when placed in a horizontal polaristation.

Secondly a delta loop antenna still wont perform to its maximum performance when placed vertical ( it still isnt fully vertical but has also horizontal components). That means your gain will have dropped with 1..2 dB. (for vertical)

The 2el Cubical Quad wont have those issues.
Its turning diameter would almost be half of that, and the horizontal component is much less when placed vertical.

The only downside would be ...it needs some room "under" the antenna for clearance.


@ BJ radionut, If seen your post.. if i wont forget ill get back to your findings later.
(ill need to find my flame suit first too )

Kind regards, Henry

 

[Crawdad]

Somebody, somewhere has a PDL-2 still in the box that's for sale............

 

[Greg T]

I would not rule out the 2el Cubical Quad BJ mentioned...

You have stated you would like "vertical" polarisation, and better results then your present vertical.

That means the delta loop has to be on the flat side in alsmost a "<" shape.
( One leg needs to be horizontal.)

One of your primairy reason to think about the 2el Delta loop was its turning radius.

If the antenna is configurated to work vertical, the turning diameter will be well over 7 meters... say 25 feet.. this is a lot more then when placed in a horizontal polaristation.

Secondly a delta loop antenna still wont perform to its maximum performance when placed vertical ( it still isnt fully vertical but has also horizontal components). That means your gain will have dropped with 1..2 dB. (for vertical)

The 2el Cubical Quad wont have those issues.
Its turning diameter would almost be half of that, and the horizontal component is much less when placed vertical.

The only downside would be ...it needs some room "under" the antenna for clearance.


@ BJ radionut, If seen your post.. if i wont forget ill get back to your findings later.
(ill need to find my flame suit first too )

Kind regards, Henry

Appreciate the info. Yeah, I was thinking about that last night. I did some research and found that many, if not most with beams are using H polarization rather than vert. After thinking it over, I may just go that route because everyone says it cuts the noise in half, and sometimes even more. Then I began thinking more (my downfall), and I figured that with so much ground effect, buildings, trees, cars, etc, that a signal must fluctuate between H and V before it gets to the intended target anyway. Am I wrong? I'm thinking signals bounce and change as they travel, so is there TRULY a big difference in polarization?

 

[TM86]

Appreciate the info. Yeah, I was thinking about that last night. I did some research and found that many, if not most with beams are using H polarization rather than vert. After thinking it over, I may just go that route because everyone says it cuts the noise in half, and sometimes even more. Then I began thinking more (my downfall), and I figured that with so much ground effect, buildings, trees, cars, etc, that a signal must fluctuate between H and V before it gets to the intended target anyway. Am I wrong? I'm thinking signals bounce and change as they travel, so is there TRULY a big difference in polarization?

Not really. Horizontal does give you a lower take off angle, so more of your signal bounces off the ionosphere. But, yeah, after a bounce or two the polarization can be anywhere from horizontal to vertical or anywhere in between. Propagation is weird like that.

 

[Henry HPSD]

As soon as your signal hits (vertical or horizontal) the layers it breaks up in the ordinairy and extra ordinairy wave. Your signal will start to rotate.
But it rotates so fast... there is no difference between either vertical or horizontal anymore.(in 99 percent of the cases) on the receiver side.

So, from that point op view there is no benefit.

(ps...i do remember reading there seems to be a sligth advantage for RHCP polarisation though most observation were done with NVIS communication on low frequencies, i dont recall reading RHCP in favour for higher HF frequencies).

Anyway...for DX on 27MHz....vertical or horizontal... there is no difference.
From just the polarisation point of view.

This is the reason why you can work people with beams on vertical from the otherside of the world, where you might expect to work vert..vert.. and hor..horz.. but that just isnt the case is it ?

If you place a horizontal antenna low it will actually have a much higher take-off angle then a vertical.
But as soon as you place that horizontal antenna say above 6...8 meters the main take-off angle, which could still be higher then a (low) placed vertical.... gains a bonus which is called groundgain.
SImply said...your signal transmits from the antenna.. that signal will also reach "ground" and bounches back up...if those two are in phase it adds.
if you place that horizontal antenna higher...the take-off angle will go down and "DXing" will become easier.

Vertical polarisation doesnt have that....
That is the reason why for DX high horizontal antennas are preferred.

But verticals did have a relative low angle, they dont need height as the horizontal antenna did.
That is why verticals are preferred on low bands (1,8...3,6MHz etc) for DXing as you simply cant put up a horizontal so high from a mechanical point of view.

Back to 27MHz...Sometimes it actually is wise to set a vertical "near" ground instead of high on a mast in order to "gain" more at low angle.
This all depends a bit on the "values" of the ground around the antenna.

PS a lower take-off angle doesnt necessarily mean "more" is reflected, but It does mean you will hop" further.

You can find some graphs on my site under "additonal information".
(how high should i place....etc)

Kind regards,

Henry

 

[Greg T]

As soon as your signal hits (vertical or horizontal) the layers it breaks up in the ordinairy and extra ordinairy wave. Your signal will start to rotate.
But it rotates so fast... there is no difference between either vertical or horizontal anymore.(in 99 percent of the cases) on the receiver side.

So, from that point op view there is no benefit.

(ps...i do remember reading there seems to be a sligth advantage for RHCP polarisation though most observation were done with NVIS communication on low frequencies, i dont recall reading RHCP in favour for higher HF frequencies).

Anyway...for DX on 27MHz....vertical or horizontal... there is no difference.
From just the polarisation point of view.

This is the reason why you can work people with beams on vertical from the otherside of the world, where you might expect to work vert..vert.. and hor..horz.. but that just isnt the case is it ?

If you place a horizontal antenna low it will actually have a much higher take-off angle then a vertical.
But as soon as you place that horizontal antenna say above 6...8 meters the main take-off angle, which could still be higher then a (low) placed vertical.... gains a bonus which is called groundgain.
SImply said...your signal transmits from the antenna.. that signal will also reach "ground" and bounches back up...if those two are in phase it adds.
if you place that horizontal antenna higher...the take-off angle will go down and "DXing" will become easier.

Vertical polarisation doesnt have that....
That is the reason why for DX high horizontal antennas are preferred.

But verticals did have a relative low angle, they dont need height as the horizontal antenna did.
That is why verticals are preferred on low bands (1,8...3,6MHz etc) for DXing as you simply cant put up a horizontal so high from a mechanical point of view.

Back to 27MHz...Sometimes it actually is wise to set a vertical "near" ground instead of high on a mast in order to "gain" more at low angle.
This all depends a bit on the "values" of the ground around the antenna.

PS a lower take-off angle doesnt necessarily mean "more" is reflected, but It does mean you will hop" further.

You can find some graphs on my site under "additonal information".
(how high should i place....etc)

Kind regards,

Henry

GREATLY appreciated, Henry!! This was kinda the conclusion I was getting when I was thinking about the signal bounce. I was not aware of the ground gain, though, which is a welcomed addition. This kind of solidifies my idea of the V quad, then. Horiz polarity mounted approximately 25 to 30 feet to the mounting point is where I will end up to make it easier to install and service. They're inexpensive, show decent gain and are light enough for me to handle on a shed roof. I'm going to check out your site as well. I was never before interested in a beam, but have recently got the urge because sometimes I can have a hard time hearing some folks 10 miles away when conditions get rough. Excellent info, Henry. Thank you!