This post is very late. The actual date of the events within it are just before March 2009 in preparation for the Virginia QSO Party.

In the many posts within this site, it is no secret my examination of various vertical antenna solutions with comparison between BigIR and the 43 Foot products a big part of this. Check out all the 43 Foot posts on HHD here…

43 Foot Antenna Selected
I chose the DX Engineering 43 Foot quick taper model during the price war between DXE and Zero Five. Compromises understood and simulations complete, I carefully considered the Big IR, but liked the idea of no moving parts or switches at the antenna location.

Back in Black
A bare aluminum antenna would stand out too much in my neighborhood so I decided to paint the antenna black. Priming aluminum is a topic I researched very carefully to be sure I applied a lasting finish. As shown below, I applied regular flat black paint over the primed aluminum pieces except where the pieces slide into each other; If you are going to paint your antenna, you need to mask the mating four or five inches of the lower end of each tube.

Conductive Compound
I used the recommended aluminum conductive anti-oxidant compound suggested by DXE on all physically and electrically mating aluminum surfaces. This results is a gooey mess the first few times you apply, but you get the hang of the proper amount soon.

Antenna Tilt Base – Cumbersome
The “kit” from DX Engineering included an Antenna Tilt Base which I gladly installed. It works great. However, you need to really watch what you are doing when lowering the antenna. If you do not seat the lower pivot bolt properly, you will bind it and/or the top sliding bolt and may simply cut it off.

You are well advised to pay very close attention to what is happening to your tilt base while moving it. If you cannot handle the antenna yourself, enlist the aid of a friend who takes direction well. The good news is you will get the hang of raising and lowering your antenna as you realize you will need to apply some downward pressure during transition.

Basically, you will need to hold the antenna nowhere near its center of gravity and manipulate it just as if it was not attached to anything; You and your two widely spaced hands are the antenna support, not the tilt base pivot point. This ensures you are able to “encourage” the tilt base bolts into the correct slots and keep them there during lowering. The 43 foot antenna is not too heavy, but, in my opinion is very cumbersome due to its length and floppy nature.

Photo Gallery

Radials
You probably noticed only eight or so radials on this 43 foot antenna system. Yes, I know… I need more and plan on installing more soon. On 20 and 40 meters, the feed point impedance is something north of 200 ohms (or something highish). It does not take many radials to create a ground resistance lower than that. However, 60, 80 and 160 meters are a different story. I will add more radials.

Performance – Good enough
With all the simulations I performed in EZNEC…

…I was not expecting more out of this antenna than possible. I knew it would be pointless for 10 and 15 meters. It knew it would provide good results for 20 meters. It would be close to a 1/4 wave 40 meter vertical. It would provide some results on 80 meters. It would stink on 160, yet still provide “something” to use for this difficult band.

In short, it has met all my expectations quite well. I now have one antenna that provides access to the major low sunspot HF bands while sacrificing 15, 12 and 10 meters during this sunspot low. This was the plan for the 2009 Virginia QSO Party and that’s exactly how it worked out.

Comparisons
I had a 75 meter turnstile antenna in addition to this 43 footer during the March 2009 QSO Party. The turnstile out performed the 43 foot vertical in almost every way on 80/75 meters. However, I did use the vertical to pull out one of our roving mobiles about 250 miles away during the QSO Party – I transmitted to him on the turnstile and received on the vertical; I would not have been able to work him without the vertical in the mix. For those wondering, I use the 8 port DX Engineering remote antenna switch – the smaller one – at the end of 240 feet of LMR-400 coax for my ‘antenna yard’ switcher.

40 meters was a bit of a toss up. Most of the time I used the vertical. However, I occasionally tried the 80 meter turnstile on 40 and it did work.

20 meters was tough due to a big DX contest the same weekend as the Virginia QSO Party. I had a tough time competing with the big guns. However, casual operating later revealed the 43 foot vertical does work pretty well on 20 meters.

Attempts at 15 and 10 meter contacts with the vertical are laughable. Zero success, but that’s not a surprise, thus I am not worried about it.

Conclusion
I am very happy to have this antenna. Except for certain times of the year, it is the only HF antenna I have available operating year round. For a single simple antenna (remember no moving parts), it provides at least some coverage on 160-20 meters with best results on 40 and 20 meters. Good enough for the moment.

However…

Those sunspots are coming back and I will lust after a solution for 17-10 meters very soon. My next project will likely be the hex beam as a simple solution for those bands. I will need some kind of support for this antenna which adds to the complexity.

When you compare the steps required to raise even a modest antenna like the hex beam, it is quite obvious no antenna solution will be as simple as the 43 foot vertical even after I took the time to paint it black.

The 43 foot antenna provides, for me at least, a very good value for the money, real-estate and simplicity. I would do it again and humbly suggest it to anyone who needs a single, simple, reliable, stealthy antenna and/or wants an additional “choice” for their antenna farm.

See you on the bands…
73

After much simulation and trading the benefits against pitfalls, I purchased the DX Engineering 43 foot antenna kit with the balun.

However, a shiny aluminum antenna in the back yard would attract the kind attention I just don’t need. Research on the Internet reveals several solutions including:

• Paint the antenna camouflage
• Wrap the antenna with black electrical tape
• Just spray some black Krylon on the aluminum and when it flakes off, it will be a kind of camouflage…!??!
• Paint the antenna flat black

Flat black objects do seem to hide themselves quite well so this is the color I decided for my 43 foot antenna.

However, I know all too well for a paint job to last you really need to do your homework. Despite advice to the contrary, priming first is absolutely necessary.

What primer paint is best for bare aluminum?

After researching this question for three weeks, the most popular answer is to use Zinc Chromate primer paint for bare aluminum. Zinc Chromate dates back to before WWII and was used extensively for all aluminum aircraft parts.

If you might be wondering if the Chromate in Zinc Chromate is dangerous, it is. It is hexavalent chromium (Chromium VI), a known carcinogen. This is the chemical of Erin Brockovich fame. As such the availability of products containing Chromium has waned in recent years. Substitutes for Zinc Chromate are readily available. However, after three weeks research, it became clear that nothing beats real Zinc Chromate for priming bare aluminum.

I went to a local aircraft repair shop thinking they have to paint aluminum often. A quick call revealed they carried Zinc Chromate primer. I went up to the counter and thay rang my up one can of Zinc Chromate primer paint in a spray can. When they handed me the product, I carefully read the label for the usual warning related to exposure to Chromium VI. There were no warnings. Sure enough, the product they list in their very own SKU system as Zinc Chromate Primer has no Zinc Chromate. I kindly returned the can to the sales desk and left.

No local source of Zinc Chromate could be found. I wound up ordering two cans online. I was not sure about that second can, but I wanted to get a bit more for just a little more shipping costs. It turned out we needed the second can.

You might be wondering why I am going to such bother to paint my new 43 foot aluminum antenna with so many steps: wash, sand, wipe, prime once, prime twice, paint. That’s a fair question since hams are notoriously cheap in their purchasing.

I am not that kind of ham.

While I do not have an Orion II and SteppIR DB, I don’t try to short change things I really can afford to do. If applying this much energy to painting yields an antenna paint job that will hold up longer than just spray and pray, then I think I have actually found the better value in the long run.

I have learned much during this research…

• Zinc Chromate has been the primer of choice for bare aluminum since before WWII
• Zinc Chromate is dangerous and a breathing mask is essential
• Sanding dried Zinc Chromate primer is also dangerous
• Zinc Chromate is paint with Chromium VI – watch out for fakes
• Zinc Chromate is NOT a paint color – depending on the formulation, it might be green, yellow, dark red and other colors
• Sanding or similarly prepping the metal surface is essential for good priming
• Access to a paint booth is a big advantage
• Making the pipe holding frame allows you to spray many smaller pipes at once thus wasting much less paint

I will let the primer cure for the full 48 hours suggested on the can and then apply two coats of flat black paint from the local home store when I get a chance.

I am thinking about getting a 43′ vertical to use on 160 to 10 meters.

Has anyone calculated the coax loss for 100 feet of RG-213 coax, especially on 80 and 160 meters?

Would it be beneficial to build a remote tuner [like below] and place it at the base of the 43′ antenna to reduce coax loss?

Remotely Tuned 43 Foot Vertical Antenna

This is the story of how I constructed the ground mount for it.

First a related story…

The day after Christmas my son and I carefully replaced the current copper pipe 16 foot vertical with the pieces from the kit which includes a nifty tilt-base, 4:1 balun and lots of hardware. The details of the actual 43 foot antenna installation will be detailed in another post. For now, I am here to tell a story of how to accommodate the needs of the XYL.

While my son and I were assembling the antenna some 200 feet away from the house it appears the mother-in-law and my wife were not liking what they saw. The wild imagination expressed by by mother-in-law included statements like “It will take five people to carry that thing” and “they should not bend it like that” and “I would not have that in my yard” and, well… sigh.

This got my wife all upset, but her personal concern was actually valid… the antenna will spoil the view. Of course a view with any antenna in it is art to me, but we have spectacular sunsets in our backyard unobstructed by any buildings and my new extension from 16 feet to 43 was going to push her patience. So this article describes how we prepared a new location for the antenna behind the trees, but still in a reasonable location. Lessons learned from the previous installation are applied.

As for my mother-in-law it is quite amazing what folks will say about things they know nothing about to try and let others think they do resulting in everyone knowing they don’t. Foot in mouth syndrome.

Anyway…

When I installed the original pipe in the ground I learned several lessons and continued to hear more good ideas as time went by. Thoughts include:

• Use a 2 inch OD metal pipe for the antenna stake
• Use gravel rather than concrete
• No Weeding

Let’s explore each point in detail.

Use a 2 inch OD metal pipe for the antenna stake
DX Engineering has clamps designed for this diameter – I found black plumbing pipe 1-7/8 inch OD (1.5 inch ID) which seems to be good enough.

Use gravel rather than concrete
This is an idea learned from one of the many ham email reflectors I monitor. I considered using concrete to secure the pipe in the ground, but ran across one fellow in a post who suggested using gravel instead. His thought was gravel will continue to settle and pack ever tighter as the pipe wiggles from the load. His concern about pouring a concrete post hole pier is the dirt could loosen around the cylinder and cause antenna tilt which would be difficult to fix; Indeed a proper concrete pier involves a wide and deep foot which creates more work than probably necessary.

No Weeding
A hard core requirement for this new antenna footing is no weed trimmer to maintain it – mower only please. My old antenna location did pretty well in this regard, but grass did grow “into” the radial plate from the perimeter requiring occasional hand trimming. This time I want to extend the “no growth” zone to well past the edge of the radial plate.

So my son and I proceeded to create the new antenna base for this new vertical antenna.

Resulting in…

Ground Antenna Mount with Antenna Base

The antenna mount is ready and shown with the bottom components of the DX Engineering 43 foot antenna system.

One good idea expressed by a local club member is to define the edge of the circle with landscaping edge material. This will help keep the rocks in and the grass out. This is a great idea and I did just that. Thanks Frank!!

Another good idea is to replace the surface gravel with landscape stone or pebbles… perhaps dark brown. This is a good idea and I will probably do it, but one has to ask how much effort does one put in to “decorating” an antenna mount when the antenna itself remains so obvious.

There is currently only one thing that might be an issue with this mount… the ground pipe easily turns in azimuth. This is not too big a deal with a vertical antenna, but could be a problem if there is some kind of directional antenna on this system. Concrete would certainly solve this. I am not too worried about this issue, but felt it wise to note it.

The final result is I have a new location for the antenna which is more XYL friendly, does not spoil the view of our sunsets and is ready to accept my new 43 foot antenna, ground radial installation and coaxial cable routing.

Stay tuned for upcoming posts.

Both antenna types approach the vertical HF antenna problem with unique solutions.

The 43 foot antenna never changes height. Its height is such it never places the high impedance part of the antenna at the feed point at any desired operating band to give a tuner a chance to turn this wild impedance to 50 ohm resistive.

The BigIR literally adjusts height to make itself just the right length to resonate and bring the feed point close to 50 ohm resistive.

These are two interesting and opposite solutions.

Let’s look at the plots for 10, 15, 20, 40 and 80 meters again…

BigIR vs 43 Foot at 10 meters

- – - – - – - -

BigIR vs 43 Foot at 15 meters

- – - – - – - -

BigIR vs 43 Foot at 20 meters

- – - – - – - -

BigIR vs 43 Foot at 40 meters

- – - – - – - -

BigIR vs 43 Foot at 80 meters

BigIR points include:

• Beats the 43 foot handily at 10 meters
• The 1/4 and 3/4 modes for 10 and 15 meters offers a great choice in antenna pattern
• No antenna matcher required since the antenna length does the tuning for you
• Antenna SWR under 2:1 a completely reasonable expectation
• SteppIR’s clever variable length antenna and optional 80 meter coil have moving parts resulting in complexity
• BigIR needs 4 (or 8 with 80 meter coil) control wires to operate antenna from shack
• For what you get, the antenna cost is a great value, but is, indeed, not cheap

43 Foot Antenna points include:

• Provides a significant benefit for 20 meter DX with good gain and potentially low take off angle
• Requires some kind of antenna matcher for every band except, perhaps, 60 meters, at antenna feed point or in the shack
• Balun helpful to ensure currents are fully driven to antenna if not using matcher at the antenna base
• Arguably much simpler antenna system with no moving parts
• If matcher located at antenna base, additional wiring required

…and…

• Neither antenna differs much at 40 and 80 meters
• The 43 Foot antenna may provide some use at 160 meters – better than nothing I guess
• The 43 Foot antenna system between 1/3 to 1/2 the cost of the BigIR system not including the required antenna matcher for the 43 foot system

Which one to pick? Well, for me the answer is not obvious. I like antennas that present low SWRs to the feedline. I like simple antenna systems. I also like 20 meters a lot. I have no problem with the cost of the BigIR.

One obvious answer is to get one of each and switch between the two. Well, I do have the room and do have the switch. However, the whole point of the Shootout is to decide the most effective antenna if you could only have one.

With the upcoming sunspots the 10 and 15 meter bands look very attractive and a good ground mounted vertical may be just the thing. However, I have got to wonder if a modestly high 10 meter dipole won’t work better than the ground mount.

I am inclined to take advantage of the DX Engineering Zero Five price war and just get the 43 Foot antenna for now since it is a plug and play system to replace my current 16 foot vertical (which works great on 20).

My preparations focus mostly on the Virginia QSO Party where NVIS 40 and 80 meter antennas along with a decent 20 meter DX antenna are a great combination.

Whatever choice you make it is nice to know great products like the BigIR and the 43 Foot offerings are available. Just remember to not cheat yourself concerning a good ground system; Both antenna systems are incomplete without it. You need lots of radials. Read the ARRL Antenna book to nail down the reasons why.

A good vertical antenna is a sensible first antenna and a great addition to your dipole. Either choice will offer the possibility of lower takeoff angle to improve your chances at DX contacts. These two choices deserve a good hard look for your first or next vertical.

The 43 foot antenna uses an antenna matcher (tuner) somewhere in the transmission line to offset the non-resonant impedance; This is the case for all bands except, possibly, the 60 meter band where 43 feet is close to a quarter wave.

The BigIR max height is about 32 feet or about an 1/8 wave antenna. The BigIR continues to not need an antenna matcher by adding an inductance in series with the 32 foot radiator. This inductance brings the antenna system into resonance with a resulting impedance of about 13 ohms. A 4:1 balun wound on an internal toroid transforms this to about 50 ohms… a slick system.

Here are the two antennas with radials appropriate to 80 meters…

The 43 foot and BigIR antennas in EZNEC

…and the plots…

43 Foot and BigIR Compared at 80 meters

Very very close…

Points include:

• Both antenna exhibit 0 dBi gain peaking around 25 degrees
• Like with 40 meters, the 43 foot antenna puts just a little more higher current conductor higher in the air, but just a little
• The SWR for the BigIR calculates fine for this, but I have found EZNEC a bit difficult to predict SWR with real-world lengths. The folks at SteppIR suggests the SWR will be under 2:1 for the 80 and 75 meter bands when using their 80m option coil
• I could not simulate any respectable SWR with EZNEC for anything between 3.5 and 4.0 MHz – I suspect your results may be better since folks seem to have reasonable results

I would call these results a wash. Both antennas work on 80 even though both are short for this band. It might seem surprising they are so similar despite the height difference. However, this pattern similarity reveals not all of an antenna’s length is actually used for radiating effectively. Indeed, the high current portion of the antenna does much of the work and in this case the lower portion of the antenna is this higher current area.

Here are the two antennas with the current magnitudes at 7.15 MHz.

The two antennas energized with 7.15 MHz.

Once again, the 1/4 wave antenna’s currents are nil at the top and maximum at the bottom. Assuming you have a good radial system on the ground with low ground resistance this should be near the ideal of 36 ohms impedance. This results in a SWR of about 1.4 or so. The fact the BigIR’s 32 foot height won’t simulate a low SWR is probably the result of simulation artifacts. Either way this is good demonstration where the ideal SWR of 1:1, where the feed point impedance is 50 ohms and a good match for the coax, is not the ideal since this means you have 36 ohms antenna reactance (turns your RF into signal) + 14 ohms ground resistance (turns your RF into heat). That’s another story though.

Here is the plot…

43 Foot vs. BigIR Vertical at 7 MHz

Hmmm, not that different… not that different at all. Points include:

• Both antennas show their best lobe of energy at about 27 degrees elevation at -0.5 dBi gain
• The 43 foot has just a little more higher current radiating portions of the antenna a little higher than the BigIR
• The SWR (at least for the 36 simulation model) is nice and low
• The SWR for the 43 foot is about 5:1 for 50 ohm feed and a respectable 3:1 using the 4:1 transformer

Neither is a clear winner. The good news is neither is a clear loser. They both do the job of getting radiating metal up in the air to make contacts.

The 43 foot antenna provides the potential for better efficiency since its impedance is much higher than the ground losses induced by the radial system. This suggests you might be able to get away with a worse radial system with less efficiency penalty… I still would put a lot of radials in since it is so easy to do.

Onward to 80 meters next…

As always, each EZNEC simulation is based on a model from the excellent collection of NEC files available from the late Cebik.

Here are the two antennas with the current magnitudes at 14.1 MHz.

The two antennas energized with 14.1 MHz

As usual, the 1/4 wave antenna’s currents are nil at the top and maximum at the bottom. Assuming you have a good radial system on the ground with low ground resistance this should be near the ideal of 36 ohms impedance. This results in a SWR of about 1.4 or so. This is good demonstration where the ideal SWR of 1:1, where the feed point impedance is 50 ohms and a good match for the coax, is not the ideal since this means you have 36 ohms antenna reactance (turns your RF into signal) + 14 ohms ground resistance (turns your RF into heat). That’s another story though.

Here is the plot…

43 Foot vs. BigIR Vertical at 14 MHz

Well well, the 43 foot has some clear benefit here. It potentially has a lower take off angle and a bit more gain than the 1/4 wave. It is not staggeringly better, but if you are trying to get every dB you can, the 43 foot wins. Points include:

• The 43 foot vertical has its peak lobe at a nice low angle of 16 degrees with a gain of about 1.3 dBi
• The 43 foot has a full half-wave radiating section well above the radiating portion of the 1/4 wave which may help your signal clear local obstacles
• The 1/4 wave BigIR has its peak lobe at 27 degrees with -0.3 dBi.
• The SWR for the BigIR is around 1.5… perfect
• The SWR for the 43 foot was far more than 10:1 with a 50 ohm coax feed. If you have a 1:4 balun the SWR gets tamed down to around 7:1. Obviously a matcher is needed and contributes its own losses

Who wins? Well I don’t know. Analysis is showing clear benefits, but nothing that would move the S-Meter more than a couple of S-Units.

The fact the BigIR is tuned by adjusting its height makes it possible to reach the theoretical 36 ohms. This puts significant requirements on your radial system if you are to have good antenna efficiency.

The very fact the 43 foot antenna is being fed at a higher impedance point suggests the radial system’s impedance need not be as low to maintain good efficiency. Then, however, there is the need for the tuner somewhere with potential added losses.

I am using the equivalent of the BigIR with my 16.6 foot copper pipe monopole antenna in my backyard over 28 radials each 33 feet in length. It works on 20 meters, but I am not busting pileups with 100 watts. Would the 43 foot approach give me an edge with everything else being the same?

Stay tuned for more band analysis.

All three antennas, the 43 foot and the BigIR in 3/4 and 1/4 wave mode and their antenna currents are shown below.

All three antennas running at 21 MHz

The current profiles for the 3/4 and 1/4 mode are just like any other antenna the same electrical length. The 43 foot antenna constrains the electrical length to around 7/8 wavelength.

Here are the three patterns superimposed…

Elevation Gain Plots of 43' and SteppIR BigIR 21.2 MHz

Here we see:

• The 43 foot vertical has its peak lobe at 37 degrees with gain of 4 dBi
• The 3/4 wavelength mode of the BigIR has its peak lobe at 47 degrees with a gain of 3.8 dBi
• The 1/4 wavelength mode of the BigIR has its peak lobe at 27 degrees at 0 dBi gain
• The SWR for the BigIR is nice and low for both the 1/4 and 3/4 mode. It was slightly better in the 3/4 mode.
• The SWR for the 43 foot was off the charts

The 43 foot vertical definitely requires a tuner. Both DX Engineering and Zero Five suggest if you are going to use the tuner in your shack then place a 4:1 transformer at the antenna feed. This converts the 50 ohm coax impedance to 200 ohms. Indeed, when EZNEC is used to check SWR at 200 ohms, it is far lower, but still about 5:1.

At 15 degrees or so elevation all three antennas show similar energy with the BigIR showing an edge in both the 1/4 and 3/4 wave modes. At higher elevations the 43 foot begins to show an advantage.

It is hard to declare a winner with this data. We will need to analyze more bands. Stay tuned to the RSS feed.

All three antennas are shown below with the relative currents displayed.

All three antennas at 10 meters

Since 28 MHz is so short, the current profile along 43 feet of vertical radiator is long. The SteppIR BigIR in 3/4 wavelength mode shows a full half wave of current high up along with the 1/4 wave at the bottom. This is, of course, the definition of 3/4 wave. Finally the simple 1/4 wave vertical mode is on the right.

Here are the three patterns superimposed…

Elevation Gain Plots of 43' and SteppIR BigIR

The following characteristics are revealed:

• The 43 foot vertical has its peak lobe at 56 degrees with gain of 5.6 dBi
• The 3/4 wavelength mode of the BigIR has its peak lobe at 47 degrees with a gain of 3.9 dBi
• The 1/4 wavelength mode of the BigIR has its peak lobe at 27 degrees with a gain of 0 dBi
• Suprisingly, the SWR calculated from 28 to 29 MHz was well under 2 and often under 1.5 for each antenna

This comparison reveals each can work at 10 meters, but one has to argue the 43 foot antenna’s angle of radiation is a bit too high for practical use.

The 3/4 wave mode of the BigIR edges out the 1/4 wave mode just slightly at the low angles we desire for long haul DX. Still, who knows, you might gain some benefit from the 3/4 mode if your soil conditions and location are different and the BigIR lets you choose either. Another way to look at the 3/4 mode is a large half-wave radiator is somewhat elevated which may help clear obstacles close by; That could be a serious benefit over 1/4 wave. Pretty nice.

Next time we will analyze the 12 meters band the same way as above and keep going until we hit 160… or maybe just 80.

Stay tuned to your RSS feed.

Trap verticals have been around for decades and many use them with success. However, two new designs have achieved some notice and are attempting to eat into the trap vertical market: The 43 Foot Tuner Required Fixed Length antenna and the Variable Length SteppIR BigIR antenna.

During this shootout we will compare a 43 foot antenna with the BigIR one band at a time. The base model for this analysis will use a ground vertical model from Larry Cebik’s NEC model collection which simulates the benefit of a good radial system. The radial lengths will be adjusted for each band and will be identical for both the 43 foot and the BigIR. The 43 foot vertical will, of course, never change height. The BigIR will be “adjusted” in height for minimum SWR at the test frequency. Where the BigIR can be 3/4 wavelengths height that will be calculated too.

HF Band Analysis:

Band	Antennas		Notes
	43 Foot	BigIR
160 m	1/12 wave	n/a	The Top Band is great, but both antennas are woefully short
80 m	1/6 wave	1/8 wave	Having an 80 meter vertical is worth while
60 m	1/4 wave	1/6 wave	Its nice to have a way to use this new band
40 m	1/3 wave	1/4 wave
30 m	4/9 wave	1/4 wave	WARC bands are often the forgotten bands
20 m	5/8 wave	1/4 wave	This is an important DX band
17 m	4/5 wave	1/4 wave	Another good WARC band
15 m	7/8 wave	1/4 and 3/4 wave	We will compare three antennas since the BigIR can tune 15 m two ways
12 m	17/16 wave	1/4 and 3/4 wave	Ready for sun spots
10 m	5/4 wave	1/4 and 3/4 wave	Ready for sun spots
6 m	9/4	1/4 and 3/4 wave	Just for fun

Note, all the above comparisons have the antennas ground mounted, not elevated.

The big 43 foot next to the BigIR set to 10 meters 1/4 wave

We will analyze each band in turn in upcoming posts and link to them from here so bookmark this page now and stay tuned…

If you install a 43 foot vertical in your back yard, route the coax through a switch and handle the tuning inside your ham shack, you need to ensure you do not exceed the voltage or current limits of the relays in the switch.

This issue comes from the expected high SWR on the coax. When there is high SWR on any transmission line you will have points along the line that may be high current or high voltage. Either could exceed the limit of the relay.

The good folks at DX Engineering confirmed my 8 port switch I purchased from them can handle an SWR of about 2:1 at full power. Everything else being the same this limit will climb as power is reduced.

The point is if you are using the tuner in your shack to load up the 43 foot vertical along with its transmission line, that transmission line has high standing waves on it which will cause trouble for anything in its path… like a switch box.

If you insist on tuning the 43 foot antenna in your shack you are well advised to connect it straight to your matcher.

If you are using a switch, as I am, that is in the RF path for the 43 foot vertical, you should seriously consider placing a tuner at the base of the antenna to avoid the high SWR issues on the coax.

Perhaps he is right for many things, but for ham radio folks evaluating antenna choices a popular answer for the height of a vertical antenna for the HF bands appears to be 43.

Be sure to check out the many posts about the 43 foot antenna here at Ham Help Desk.

If you have been in the market for a vertical you have probably noticed the availability of a “tuner required” vertical which is forty-three feet in height above a reasonable ground plane of radials. Indeed Zero-Five, DX Engineering and others offer this exact configuration in their model lineup claiming “all band” operation from 160 to 10 meters. Can this really be true?

This is also known as a 13 meter vertical. Here is a discussion of why this compromise length exists with some pitfalls.

Forgoing the need for a tuner (which is arguably not too big a deal) let’s have a look at the predicted patterns using EZNec. To set up the simulation, I copied a vertical antenna with four radials from the Cebik model set available for purchase on his web site. The only thing I changed was the antenna height and the radial length.

• Antenna height = 43 feet AGL with the bottom about 3 inches above ground
• Four Radials of 1/4 wave each to simulate an efficient low impedance ground resulting from layout of many radials

I chose Cebik’s vertical example to ensure I leverage his knowledge of how to model radials reasonably well in EZNec which, in my case, uses NEC2 as the engine. NEC2 does not model underground radials so Cebik’s technique is a welcome insertion of NEC2 trickery. Plus, I wanted to capture all the appropriate assumptions he makes for vertical over radials EZNEC antenna simulation.

The antenna looks like this…

View of 43 foot vertical antenna in EZNEC

Now here is the predicted patterns using a typical frequency of the main HF bands. Note the “Primary” trace is the one plotted for the 10 meter band…

Patterns of 43 foot Vertical Antenna on the major HF Bands

The peak radiation angles and relative antenna gain for each bands are:

• ~ 5 dBi @ 57° for 10 meters – impressive, but high angle
• ~ 4 dbi @ 37° for 15 meters
• ~ 1 dBi @ 16° for 20 meters – nice low angle
• ~ 0 dBi @ 25° for 40 meters
• ~ -2 dBi @ 29° for 80 meters – this is quite functional
• ~ -8 dBi @ 23° for 160 meters – lossy, but it does work

Several things are apparent:

• The antenna has “better than nothing at all” performance on 160 meters and is certainly interesting for this difficult band.
• Low gain, but good low angle performance is apparent for 80 through 20 meters.
• The 15 meter band shows some actual gain, but at a high angle of about 30-40 degrees – This may or may not be what we want for our DX purposes on this band. That said, it is noteworthy to see it still has unity gain at lower angles.
• The 10 meter band, the black trace marked as Primary, shows peak energy well above 45 degrees elevation. I suspect this will be less than desirable.

You can see why the ten meter case has the high angle radiation when you look at the currents along the vertical as shown here…

View of 43 foot vertical operating at 28.3 MHz

The opposing current phases destructively interfere at some angles and constructively interfere at others.

Is this an all HF band antenna? Well, because it operates at no particular “tuned” length for any HF band, except maybe 60 meters, you will always need a tuner. So, sure, it can tune up anywhere the tuner (or matcher if you prefer) can match. If you have to have just one antenna for HF, maybe this is a good choice, especially during the current great low band conditions in this low sunspot point in time.

A better reason to consider this antenna is for reasonable 80-20 meter use and as a practical thing to try for the 160 meter band. Because you can tune almost anything to almost any band, it is possible to get 10 and 15 meter use too with the propagation issues described above.

Other advantages for this 43 foot antenna is expense. You can have one for a few hundred dollars and several major antenna manufacturers, noted above, make them. The variables between the manufacturers is likely strength in materials and other mechanical design issues. Look to Eham for evaluations.

In my quest for a do it all vertical to replace my 16.6 foot copper pipe my choices include:

1. Multiband Fixed Height Vertical using Traps
2. Multiband Variable Height Vertical using the SteppIR BigIR III
3. Multiband Fixed Height Vertical using an antenna matcher in the shack – such as this 43 foot concept
4. Multiband Fixed Height Vertical using an antenna matcher at the antenna base – 43 foot concept again
5. Forget the vertical and get a dipole

Because I am getting good results on 20 meters with my 16.6 foot vertical, I am not interested in dipole solution #5… yet. Thus, I desire to bring some closure to this vertical installation and make it the best it can be.

I am still leaning towards the SteppIR BigIR Vertical even though it is a bit expensive. Being able to tune the antenna precisely to the appropriate length is a great feature resulting is little standing waves on the coax.

However, the simplicity of solution #3 means no additional wires to the antenna to power an automatic remote tuner or drive the SteppIR motor. This is just radio (with built-in matcher), coax, antenna. I lose some power in my very long coax with the standing waves, but have a much more reliable system. Uncomplicated solutions are certainly well worth considering.

No matter what your choice, if you want a vertical, consider the investment you will need for the radial system. Get the DX Engineering Radial plate and just do it. It really helps.

One more point is worth mentioning. The various makers of 43 foot vertical antennas all suggest the use of a 1:4 balun. Some suggest using a balun model made specifically for “tuner use” with the idea these specialized units have the robustness needed to handle the less that ideal voltages and currents. A nice balun costs good coin and is certainly worth it. Just be sure to roll this expense into your trade study when comparing this 43 foot solution with something like the BigIR vertical.

Also watch out for aluminum components near the ground. Certain soil conditions will dissolve aluminum.

DX Engineering and Zero Five Antennas seem to be in hot competition in the vertical market and they both have an approximate 43 foot system to sell you. If you are in the market for this kind of vertical start your trade study with these two manufacturers.

Good luck.