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Author Topic: Vertically challenged newb, with photos  (Read 636 times)

KI6GEA

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Vertically challenged newb, with photos
« on: September 27, 2021, 09:36:10 AM »

Hey All, I need some antenna help please... I recently renewed my old technician license, and am on my way to a general license, as a new friend has fueled my first entrance into HF/DX.

I have been researching HF antenna options ad nauseum, and have a decent Google introduction to antenna types and each of their compromises... My challenge is my backyard. I'm in So Cal, and live in what locals refer to as a "McMansion". A big two story house on a very small lot. Its a two story house with a small backyard that is all concrete/swimming pool, filled with palm trees... So I don't have the ground space for radials or the air space for horizontals... This has led me to believe I must accept the limitations of a no-radial vertical.

I spent this past weekend building my initial shack, which is an FT991A to a Diamond BB7 vertical, run to 75 feet of R8X coax. The antenna is on a 15 foot mast bolted to the side of a sturdy shed on the side of the house, which is in convenient close proximity to my shack just inside the house.

I've listened all weekend, and heard as far as the east coast on 20 meters during the day, and Australia on 40 pre-dawn (although the signal was just clear enough to be decipherable, but not really clear at all)... I was encouraged by this but of course havent been able to transmit yet.

There is a flagpole in the yard as well, which I originally thought I may be able to utilize, but it's flanged by palm trees on all sides so I'm not sure what I could do there... Additionally I did try a Chameleon hybrid mini placed in a U shape around an upstairs balcony, but didnt seem to receive as well as the Diamond vertical.

I got the Diamond BB7 because it was in stock, and looked simple enough to deploy by myself as my first antenna... I probably would have gone with the Comet 250, as it is a little taller than the BB7, and seems to have better reviews. But is very similar to the BB7 in most aspects.

So my question is this: Money is no object, but physical limitations are. I want the absolute best antenna I can deploy, particularly for 20 and 40 meters, considering my space limitations... Would I do better to place a backorder for the Comet 250, or something like a Butternut or Hustler, even though I wont be able to deploy radials with these?

What would you do in my yard? Attached are a couple photo links showing my current DB7 on the shed, and the other corner of the yard with the existing flagpole (behind the swimming pool).

Thank you very much in advance for any guidance you can offer and 73's all around.

Chris
KI6GEA

Photos attached, and direct links:


https://photos.app.goo.gl/pTeaFwqvmUwJcbke8

https://photos.app.goo.gl/pTeaFwqvmUwJcbke8
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WB6BYU

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Re: Vertically challenged newb, with photos
« Reply #1 on: September 27, 2021, 10:08:17 AM »

It would be nice if the photos were somewhere that didn't require
a Google account to access...


The Diamond BB7 and Comet 250 are unlikely to feature on the list of
"absolute best antennas I can deploy" in most circumstances.  You may
want to read G8JNJ's analysis of these antennas.

Note that performance varies depending on whether the antenna is
mounted to a metal mast, and if the mast is grounded or not.


What is your vertical height limit?  A quarter wave vertical for 20m,
with elevated radials (even if they have to wrap around the house or
run along the fence) should work pretty well.  One for 40m would be
even better, although it is around 32 feet tall:  by using a dual-band
matching network at the feedpoint you can use it on both bands.

Rather than a self-supporting vertical, you can try a wire running up
one of the palm trees.

If you have a wood fence, you can use that to run elevated radials
(at least in two directions).  Mounting the antenna on the fence then
keeps it further from the house (although closer to the neighbors).
You might need to think of a way to disguise the antenna, like mounting
a bird house on it.

One approach is to use a "screwdriver" remotely tunable mobile
antenna, where the top section can be lowered when not in use so it
isn't as visible.  This could then be tuned from, say, 40m through
10m from inside the house, although it would need radials for best
performance.

Hams have used the Hustler and HyGain verticals with just a ground
post for generations.  Especially if you have good soil conductivity,
these can work well enough.  I suspect your house is stucco, in which
case having the antenna too close to it may make more of a difference
in performance than using less-than-optimal radials.

How tall are your palm trees?

Do you have metal or plastic rain gutters on the house?

What type of roof material do you have?

Is the flag pole easily removable to add an antenna to it?
Or can you add a second one?

There are lots of options, it is just a matter of finding the
one that works best in your specific situation.

W5RH

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Re: Vertically challenged newb, with photos
« Reply #2 on: September 27, 2021, 10:23:48 AM »

Street view of your place shows some beautiful Palm trees.  Probably 70 feet tall.   I'd be putting my money on an antenna utilizing those puppies.  Even phasing them.

GL...Rick  W5RH
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K1VSK

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Re: Vertically challenged newb, with photos
« Reply #3 on: September 27, 2021, 10:34:06 AM »

Not an uncommon problem. Unfortunately, now 20 and 40 are the “go-to” bands for DX and both require either a vertical with effective radial pattern or a horizontal antenna at reasonable height. The good news for you is this is a short term problem as the higher bands will soon come back to life as propagation conditions improve requiring smaller antennas at lower height.

Cobweb and Hexbeams each have a small footprint and effective to some extent at a height close to your roofline so as to conceal it from view. The options are almost endless.
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KG4RUL

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Re: Vertically challenged newb, with photos
« Reply #4 on: September 27, 2021, 10:37:47 AM »

If you decide to use the palm trees to support a wire antenna, consider this as part of the installation:
http://antennatensioner.com/drupal/
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WA2VUY

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Re: Vertically challenged newb, with photos
« Reply #5 on: September 27, 2021, 01:34:52 PM »

"NOTICE TO CUSTOMERS...Due to devistating flood damage from Hurricane Florence Vari-Ten Tensioners are no longer available and the business has been closed indefinately.  Our heartfelt thanks go out to our customers who have supported us over the years.  "
If you decide to use the palm trees to support a wire antenna, consider this as part of the installation:
http://antennatensioner.com/drupal/
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GRUMPY2021

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Re: Vertically challenged newb, with photos
« Reply #6 on: September 27, 2021, 01:44:18 PM »

DX Commander.   
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W6MK

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Re: Vertically challenged newb, with photos
« Reply #7 on: September 27, 2021, 01:53:27 PM »

So I don't have the ground space for radials or the air space for horizontals... This has led me to believe I must accept the limitations of a no-radial vertical.

You need to expand your thinking about vertical antenna systems 'way beyond what you seem to have googled. Rudy Severn has a series of articles on vertical antenna radial systems.

For example alternatives to vertical "radials" (strictly speaking) are often referred to as "counterpoises." Research this topic thoroughly and you will discover there are ways to provide very effective methods to create the second half of a vertical antenna system without requiring much space.

Counterpoise ground or radial systems can be folded, or include loading coils and in many cases can work very well with a minimal (one or two) number of elements. Tom Schiller, N6BT, a well-known antenna designer, has been producing over many years various designs of highly efficient vertical antennas which work well on 40M and higher bands and include just two radial elements. In recent years Ham Radio Outlet has been a source for these antennas which also have been available directly from the designer and builder.

You are far less vertically-limited than you imagine if you have 70 ft. palm trees which you can use as supports for wire verticals. Your limitations at this point have to do with your understanding of antenna design.
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K0UA

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Re: Vertically challenged newb, with photos
« Reply #8 on: September 27, 2021, 01:58:47 PM »

DX Commander.

That was my first thought too. Far far far far better than any Comet Cha 250b or the Diamond equivalent ever thought about being. By a factor of about 30 dB.

https://www.m0mcx.co.uk/store/products/dx-commander-premium-build-hf-multi-band-vertical-system/

Or build simple fan vertical yourself supported by those palm trees.  You would never even see them with the correct choice of wire size and color.

I wish those things like a Comet 250b didn't even exist. They promise so much and deliver so little.
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73  James K0UA

K1KIM

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Re: Vertically challenged newb, with photos
« Reply #9 on: September 27, 2021, 03:03:07 PM »

You can always run a Screwdriver antenna with a 20-40 section of fence pipe for your counterpoise on your existing privacy fence.

Tarheel etc comes to mind. It is a compromise antenna, but works.

Others can comment on this suggestion.

I thought of this as I have a wrought iron railing around my patio that is quite large, but decided on a Hustler 5-BTV with 40 32' ground radials. Obviously your space constraints won't allow this.
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So Many Toys.......So Little Time!

K6AER

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Re: Vertically challenged newb, with photos
« Reply #10 on: September 27, 2021, 05:23:46 PM »

YOU GOT PALM TREES!

Put up a non resonate dipole (40 feet each side) and feed it with ladder line from a 1:1 balun. Use an antenna tuner to feed the balun. Suspend the dipole in an inverted V configuration from the tree top. This antenna will outperform any vertical you can come up with and it will be a lot quieter than a vertical.

I use one of these antennas at 60 feet here in New Mexico and have worked over 230 countries on 40 meters in the last 4 years.
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WB6BYU

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Re: Vertically challenged newb, with photos
« Reply #11 on: September 27, 2021, 09:46:49 PM »

KG4RUL

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Re: Vertically challenged newb, with photos
« Reply #12 on: September 29, 2021, 04:36:42 AM »

"NOTICE TO CUSTOMERS...Due to devistating flood damage from Hurricane Florence Vari-Ten Tensioners are no longer available and the business has been closed indefinately.  Our heartfelt thanks go out to our customers who have supported us over the years.  "
If you decide to use the palm trees to support a wire antenna, consider this as part of the installation:
http://antennatensioner.com/drupal/

Too bad.  They made an excellent product.
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KI6GEA

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Re: Vertically challenged newb, with photos
« Reply #13 on: September 30, 2021, 01:08:37 PM »

Thanks for all the thoughtful responses everyone... W6MK this is exactly where I'm going.. Tom from ZeroFive is building me a new vertical and is helping me come up with a dual counterpoise system... What he suggested is two 30 feet wires bolted directly to terminals at the lower mast u-bolts, running out and down north and south in an inverted V.. This works well because I have decent room to the north and south but not east/west...  He implied this would create a type of dipole that would compliment the vertical. Still not sold this is the best place to attach the counterpoise to the verticals though?

Also I have been reading on the advantages of the OCF dipole, and am wondering if it would be advantageous to have one counterpoise 43 feet and the other 24 or whatever the correct OCF measurements are for 40 meters... This also compliments my space as I have plenty of room to the south for one counterpoise (50 feet maybe) but less room to the north.

Any insight you guys could offer to this vertical/counterpoise setup would be most appreciated.

73,
Chris

You need to expand your thinking about vertical antenna systems 'way beyond what you seem to have googled. Rudy Severn has a series of articles on vertical antenna radial systems.

For example alternatives to vertical "radials" (strictly speaking) are often referred to as "counterpoises." Research this topic thoroughly and you will discover there are ways to provide very effective methods to create the second half of a vertical antenna system without requiring much space.

Counterpoise ground or radial systems can be folded, or include loading coils and in many cases can work very well with a minimal (one or two) number of elements. Tom Schiller, N6BT, a well-known antenna designer, has been producing over many years various designs of highly efficient vertical antennas which work well on 40M and higher bands and include just two radial elements. In recent years Ham Radio Outlet has been a source for these antennas which also have been available directly from the designer and builder.

You are far less vertically-limited than you imagine if you have 70 ft. palm trees which you can use as supports for wire verticals. Your limitations at this point have to do with your understanding of antenna design.
So I don't have the ground space for radials or the air space for horizontals... This has led me to believe I must accept the limitations of a no-radial vertical.

You need to expand your thinking about vertical antenna systems 'way beyond what you seem to have googled. Rudy Severn has a series of articles on vertical antenna radial systems.

For example alternatives to vertical "radials" (strictly speaking) are often referred to as "counterpoises." Research this topic thoroughly and you will discover there are ways to provide very effective methods to create the second half of a vertical antenna system without requiring much space.

Counterpoise ground or radial systems can be folded, or include loading coils and in many cases can work very well with a minimal (one or two) number of elements. Tom Schiller, N6BT, a well-known antenna designer, has been producing over many years various designs of highly efficient vertical antennas which work well on 40M and higher bands and include just two radial elements. In recent years Ham Radio Outlet has been a source for these antennas which also have been available directly from the designer and builder.

You are far less vertically-limited than you imagine if you have 70 ft. palm trees which you can use as supports for wire verticals. Your limitations at this point have to do with your understanding of antenna design.
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WB6BYU

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Re: Vertically challenged newb, with photos
« Reply #14 on: September 30, 2021, 04:11:40 PM »

Quote from: KI6GEA

... What he suggested is two 30 feet wires bolted directly to terminals at the lower mast u-bolts, running out and down north and south in an inverted V.. This works well because I have decent room to the north and south but not east/west...  He implied this would create a type of dipole that would compliment the vertical. Still not sold this is the best place to attach the counterpoise to the verticals though?



The best place for radials to connect is to the coax shield at the
feedpoint.  If that is connected to the the lower mast u-bolts, that
should work well.  2 radials are sufficient when they are elevated
above ground, and tuned to resonance on the band of operation.

They do not, however, make a dipole.  The currents are flowing in
opposite directions in each radial wire, while they are flowing in
the same direction (for example, North to South) in a dipole.


Quote

Also I have been reading on the advantages of the OCF dipole, and am wondering if it would be advantageous to have one counterpoise 43 feet and the other 24 or whatever the correct OCF measurements are for 40 meters... This also compliments my space as I have plenty of room to the south for one counterpoise (50 feet maybe) but less room to the north.



There are lots of configurations that can be made to work, to
some extent.  But the radials need to be designed to work with
the vertical portion of the antenna:  you can't just mix and
match and expect good results.

With a single pair of radials, you can design a vertical that will
work with them on two bands.  Might be easier, however, if you
are using elevated radials for 20m and 40m, just to use two
quarter wave wire radials for each band.  That should work with
a dual-band vertical, which might use traps, or a dual-band
tuning network, depending on the available height you can
get away with.  You can extend it to other bands by adding
more radial wires - they can be run parallel to each other, or
angled down towards the ground with some vertical space
between them, so the higher frequency bands take up no
more space than the lowest band.
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