eHam

eHam Forums => Antennas and Towers and more => Topic started by: W2ANZ on November 23, 2012, 04:49:38 PM



Title: 43 foot verticals
Post by: W2ANZ on November 23, 2012, 04:49:38 PM
I'm getting back on the air after a 10 year hiatus.  My operating interests are 80-10 CW, both DX and local.  In my past operating I always used horizontal wire antennas.  I've compromised with my wife and agreed to a vertical this time, thus eliminating the ugly supports and feedline drop and the feedline slapping against the house siding in the wind.

It looks like the non-resonant 43 foot design is a reasonable place to start.  I don't mind using a matching network at the base, and I have seveal that should work in my collection already.  I would not be using a transformer/balun at the base.  I intend to put in a good radial system, at least 32 x 32'.   

It seems that lots of manufacturers make 43 foot verticals.  I'm looking at DX Engineering, MFJ, Zero Five and others.  I do require that the vertical be self supporting (no guys).   The manufacturers all seem to have great user ratings.  I would buy it without the balun/transformer.  The costs seem to be about the same - around $200. 

I'd appreciate any comments or feedback regarding which manufacturer has the best mechanical product.  If this is a beat-to-death topic already please forgive me.  I searched but did not find  much information.


Title: RE: 43 foot verticals
Post by: WS3N on November 23, 2012, 04:57:39 PM
I searched but did not find  much information.

I'm not trying to be a wise guy, but I put "43 vertical" into eHam search and got 13 pages.


Title: RE: 43 foot verticals
Post by: W2ANZ on November 23, 2012, 05:08:39 PM
I found that too.  And I found even more information with a Google search.  My question is simply, "which manufacturer produces the best hardware".  If that has already been addressed then I missed it.

Thanks


Title: RE: 43 foot verticals
Post by: K3VAT on November 23, 2012, 05:28:15 PM
I found that too.  And I found even more information with a Google search.  My question is simply, "which manufacturer produces the best hardware".  If that has already been addressed then I missed it.
Thanks

One can consult the "Products Review Section" of this site and get a rank-order on 43' verticals. 
WS3N is correct, this topic has dozens if not hundreds of threads.

GL, 73, Rich, K3VAT


Title: RE: 43 foot verticals
Post by: QRP4U2 on November 23, 2012, 05:34:30 PM
I use the Salas matcher

http://www.ad5x.com/images/Articles/Match43footer.pdf

with an S9 (now LDG) and am very happy with the results.

I used two T400-2 toroids in lieu of the open air coils.

Phil -  AC0OB


Title: RE: 43 foot verticals
Post by: W2ANZ on November 23, 2012, 06:31:40 PM
Thanks everyone.  I'll read the threads and product reviews a second time.  I skimmed them prior to my original post, and didn't find what I was looking for, but maybe I missed something. 

Rephrasing my original question, I'm about to pull the trigger on the DX Engineering 43' vertical. Before I do I'd be interested in knowing how it compares in mechanical quality to others such as the  Zero Five.  If anyone has experience with both the DX and another brand then I would very much appreciate hearing their opinion.   

I did not express my original question very well.  Sorry for the confusion.

Jon


Title: RE: 43 foot verticals
Post by: A9KW on November 23, 2012, 07:35:14 PM
Jon
All I can recommend is that you read the products reviews real good.


Title: RE: 43 foot verticals
Post by: KG4RUL on November 23, 2012, 08:43:14 PM
Get yourself a remote tuner such as the ones sold by MFJ.  Makes life with a vertical a whole lot more pleasant.


Title: RE: 43 foot verticals
Post by: KC4MOP on November 24, 2012, 03:13:14 AM
For mechanical attributes I would go with Zero 5. DX Engineering is pretty close for that matter.
The reason you may be sensing a lack of response for the 43 footer is that the mystery about it has been revealed and it is not a wonderful magic antenna. 20M it is a perfect 5/8 wave antenna. On other bands it will perform somewhat and then others it will be complete waste of time. QST also had a nice article on the 43 foot antenna, where it shines and where it doesn't.


Title: RE: 43 foot verticals
Post by: K0OD on November 24, 2012, 06:56:34 AM
Quote
20M it is a perfect 5/8 wave antenna.

Which is no big deal over a standard 1/4 wavelength. I've used the DXE version for several years. 43 footers are worthless only on 160 unless you add baseloading... mediocre on 80... good on 60, 40, 30 and 20. And I've found mine to be surprisingly decent on 15 and up, including even 6 meters in a pinch.  

DXE makes a thicker slow taper 43 footer which is structurally stronger. And a thinner fast taper version, which I use. So far it's been quite adequate without guying, surviving some near-bouts with tornadoes.

There's nothing special about so-called "43 footers" (none are really that size), but they are decent performing and very flexible appliance antennas for us antenna restricted older appliance ops.  High dipoles are better (and much better close-in), but 43 footers are SOOO Much more convenient and durable.  


Title: RE: 43 foot verticals
Post by: K0OD on November 24, 2012, 07:29:50 AM
Since CQWW CW is this weekend, it's appropriate to link to my detailed report on my 2008 full bore low power effort in that contest using only the DXE 43' vertical. Working 100 different countries from Missouri in a weekend proves that these verticals can absolutely work DX including some rare stuff.

Do they quickly bust huge pileups as the ZF reviews often claim?  Heck no!. But you can work plenty of nice DX with them, especially on CW, if you're persistent.
http://www.eham.net/ehamforum/smf/index.php/topic,61353.0.html

Later my experiments determined that base matching improves performance by about 3 dB on 80 meters and a whopping 11 db on 160.
 


Title: RE: 43 foot verticals
Post by: W5DXP on November 24, 2012, 07:42:58 AM
It seems that lots of manufacturers make 43 foot verticals.

Texas Towers has telescoping lengths of aluminum tubing on sale. You could probably construct a 43' vertical for around $60 or so.:)

You say you want to operate 80m-10m. 10m is good and getting better right now but a 43' vertical is not a good 10m antenna as it has a take-off-angle of 56 degrees. It's low elevation angle gain is about -6dBi, a good S-unit down from a 1/4WL ground mounted vertical.

Someone on another thread described a fan-monopole consisting of three vertical elements of 66', 44', and 22' with the ability to switch between the elements for optimum operation on any HF band 80m-10m.


Title: RE: 43 foot verticals
Post by: W2ANZ on November 24, 2012, 11:48:07 AM
Thanks Cecil and everyone.

My intent is to use the 43' antenna with a low-loss homebrew matching network at the base.   The coax line to the shack will be operated in a matched condition and will not have the extra losses caused by high VSWR.  I will not have the 4:1 torroid transformer at the base, another source of loss.  I will not use the "tuned" 150' feed line that some of the manufacturers recommend.  All these seem like band aids for someone who is unwilling to tune at the base.

I see 43 feet as about the upper limit for a freestanding vertical and also about my upper limit for the visual impact to my property.    Yes, the radiation resistance will be low on 80 and yes there will be high ground losses, but given my desire to be inconspicuous, it is what I can do. 

For operation on the high HF bands I can telescope the vertical down to a lower height to preserve the low takeoff angle.  I'm not too keen on the verticals with multiple elements (ugly) or on traps (lossy).

The idea of buying just the tubing is a good one.  I need to add up the cost of the tubing, base insulator and fold over mechanism and see how they compare to a packaged vertical.

I'm still reading through the old reviews and postings. 

Thanks & 73,
Jon


Title: RE: 43 foot verticals
Post by: K0ZN on November 24, 2012, 06:38:58 PM
Just some food for thought: you can significantly add to the mechanical reliability and/or wind survival by adding ONE set of guys at 15 to 20 ft. Level and this can be done with "stealth" guys using something like 3 strands of 25 or 30 lb. test, clear monofilament fishing line. woven into one rope. This is nearly invisible and would seriously strengthen the antenna with virtually no XYL complaints. Due to UV, you might want to replace it every couple of years, but it would be cheap mechanical insurance.

If you only have ONE antenna, mechanical reliability is pretty important.... And it may help you sleep better on some windy, stormy night!

73,  K0ZN


Title: RE: 43 foot verticals
Post by: WD4ELG on November 24, 2012, 08:18:35 PM
Speaking from personal experience, your results may vary:

1. Zero five verticals are 6063 alum tubing, fast taper.  No need for guy wires with this baby, it is self supporting.

2. I run remote tuners at the base of the vertical.  Puts as much into the antenna as possible.  No need to worry about coax losses.

3. Get radials laid down.  As many as you can do.  I have 40 at 32 foot length and 8 at 64 foot length.  Try to get them at least 32 foot long.  I use Home Depot 14 gauge stranded covered wire.  $50 for 500 foot roll.  Put down all 500 feet.  And get a radial plate like from S9/LDG or DX Engineering.

4. Remember that 43 foot antenna is not magic.  See this eham article.  Your perf on the higer bands above 17 will not be all that great.  I can attest to this, which is why I have a multiband wire antenna at 64 feet.  http://www.eham.net/articles/21272

Hope this helps.


Title: RE: 43 foot verticals
Post by: WA8FOZ on November 24, 2012, 08:50:19 PM
Quote
For operation on the high HF bands I can telescope the vertical down to a lower height to preserve the low takeoff angle.  I'm not too keen on the verticals with multiple elements (ugly) or on traps (lossy).
Sounds cool. A bit shorter will give you a lower angle of radiation and better DX on 17 and above, as you know. And if it is no hassle for you to walk out when you change bands, you can work out some sort of base loading arrangement to supplement your matching device on 80 and 160.

If I were to do this I would have an autotuner at the base, maybe the MFJ 1500 watt model, at the base; and have the option of going out to the antenna or not, depending on weather and my mood.


Title: RE: 43 foot verticals
Post by: STAYVERTICAL on November 25, 2012, 01:38:03 AM
With regards to the long radiator problem on the higher HF bands, has anyone considered putting a sliding ferrite suppressor ring on the vertical?

I can't claim this is original since I saw this in some forgotten antenna book, but it may be one way of stopping having to lower the whole tube.
Perhaps some sort of flagpole pulley arrangement on the top and a ferrite ring free to be hoisted up and down.

I am not an engineer, so I am only surmising this could act as a sliding suppressor trap, electrically shortening the antenna.
It may be totally wrong technically, but perhaps some of the genius antenna guru's could comment on this sliding ring's effect.

Another thing I saw was that if you move a capacity hat down near the feedpoint of a vertical, very little radiation will be above the hat.
If a suppressor ring is not practical, could a sliding capacity hat do the same thing?
 
I am pretty busy at the moment with my own antenna experiments/building, but I will try it when I have some free time.

73 - Rob


Title: RE: 43 foot verticals
Post by: W5WSS on November 25, 2012, 02:55:09 AM
The three lengths of wire verticals are not all left in the air and up simultaneously. Their use is superior, though when one is chosen the other two are completely down and not connected but rather rolled up and in the garage ready for deployment when needed.

The system consists of a hoist and halyard fabricated of rope to hoist one wire up vertically and hold it up. Total deployment time about 3 minutes including removing one and adding another.

The techniques used provide for a quick change between the three and allow for better pattern development where longer range dx is desired 22 ft 44ft  66ft provides for better 10m to 75m vertical performance than a single 43ft.

The cost of the system I deployed was about $20 for the rope, wire and hardware.

The antenna system utilized the three lengths and a competent network delivery system capable of handling the band excursions and legal limit power application.

The antenna system can be installed in a way where the coaxial cable feedline linking  the delivery network located at the antenna base feedpoint can be eliminated totally.This methodology completely overcomes the coaxial line losses avoiding an unmatched line.

The system counterpoise consists of tuned pairs oriented opposite relative to each other for each band 10m-40m elevated and sloped downwards to Teflon anchors driven into the ground. Note the 66ft length vertical did not have a dedicated set but relied on the shorter 40m pair as space did not allow for longer radials.

The entire elevated system can be designed and considered in 4 parts.

The three individual wire verticals
The hoist
The delivery system
The counterpoise



Title: RE: 43 foot verticals
Post by: K0ZN on November 25, 2012, 05:49:41 AM
"Self supporting" is not a guarantee, especially if you live in an area with high winds or subject to thunder storm gusts. Guys are not a guarantee either but they greatly improve high wind survival for a simple structure made of tubing. I am not going to run stress analysis on this, but a set of guys probably reduces torque on the base by 70%+. That is a very significant gain in strength. Your situation may or may not need or justify the additional support.

73,  K0ZN


Title: RE: 43 foot verticals
Post by: W5DXP on November 25, 2012, 06:40:00 AM
... has anyone considered putting a sliding ferrite suppressor ring on the vertical?

Although possible in theory, since it would be a one-turn choke, the problem would be getting the choking impedance high enough to compete with conventional traps. The characteristic impedance of a vertical is in the ballpark of a few hundred ohms (variable with height above ground) so the choke would need to exhibit a few thousand ohms of choking impedance which is tough to do with a one-turn choke but it would be easy to simulate using EZNEC.


Title: RE: 43 foot verticals
Post by: K4SAV on November 25, 2012, 10:07:52 AM
Although possible in theory, since it would be a one-turn choke, the problem would be getting the choking impedance high enough to compete with conventional traps. The characteristic impedance of a vertical is in the ballpark of a few hundred ohms (variable with height above ground) so the choke would need to exhibit a few thousand ohms of choking impedance which is tough to do with a one-turn choke but it would be easy to simulate using EZNEC.

You would need about 5000 ohms to keep the bead loss below 2 dB at 7 MHz.  It's difficult to calculate what size bead would be required since the impedance isn't a linear function of diameter, but I would expect to see a bead (probably multiple beads) weighing between 30 and 100 pounds for a 3 inch diameter mast. 

This becomes a lot easier if the radiator is smaller diameter.  For a half inch diameter radiator, a quick check shows that you could get 5K ohms with about 15 lbs of beads (based on some beads I have in hand).  With a skinny wire as a radiator, you would only need about 1 lb of 1 inch diameter #75 beads.  Anyone for designing a ferrite tuned vertical?

Jerry, K4SAV


Title: RE: 43 foot verticals
Post by: WB6BYU on November 25, 2012, 02:18:46 PM
Quote from: WA8FOZ

...A bit shorter will give you a lower angle of radiation and better DX on 17 and above, as you know.



There is a lot of theory supporting this, but it isn't always the case in the real world.  Let's consider
a full wave vertical for a moment:  the current will be about equal and out of phase in the upper and
lower halves of the radiator, so there should be no radiation broadside to the antenna.  Similarly for
a 3/4 wave vertical:  the radiation from the lower 1/4 wave is out of phase with that from the upper
1/2 wave, which tends to cancel radiation at low angles.

But when the antenna is installed in a subdivision or condo with a lot of buildings around it, the
radiation from the bottom section of the antenna may be blocked or reflected by nearby buildings,
leaving mostly that from the upper section (which hopefully is more in the clear) as the strongest
component.  That means you'll have better radiation at low angles than you would have with the
same antenna in an open field (at least in some directions.)

And even without the surrounding buildings, the signal strength from a full wave vertical really
isn't that bad: my model suggests that compared to a 1/4 wave ground mounted vertical, a
3/4 wavelength vertical is about 2dB better and a full wave radiator is less than 2dB worse
at an elevation angle of 10 degrees.  That doesn't mean that the longer vertical is ideal, of course,
but that the differences won't be huge on DX signals:  even at 10m or 6m, EZNEC suggests the
radiation at 10 degrees vertical angle is less than 2dB down from a ground mounted quarter
wave vertical (though such an antenna isn't particularly popular for 6m weak-signal work.)


If you do want to improve performance on the higher bands, a "sleeve vertical" approach may
be better, using perhaps a pair of stub verticals parallel to the main one and spaced a foot or
so away from it.  This makes the bottom section act more as a transmission line so maximum
radiation is from the top section of the antenna rather than the bottom.  For example, consider
a 3/4 wave vertical with a 1/4 wave grounded section parallel to the bottom:  this would
make a J-pole (in ideal conditions) and may be more effective than a shorter vertical, as well
as being simpler mechanically than some scheme to change the element length.



Title: RE: 43 foot verticals
Post by: W5DXP on November 26, 2012, 08:19:56 AM
You would need about 5000 ohms to keep the bead loss below 2 dB at 7 MHz.

Here's another idea. Given a 44' vertical, we could turn it into a 2x5/8WL phased collinear on 10m by installing a phase shifting coil at the halfway point. If we could come up with a phase shifting common-mode bead choke, would that work? Some ferrites are mostly inductive at certain frequencies.

For instance, if I take a 44' vertical and install an EZNEC load of 0-j400 ohms at 22', it lowers the take-off-angle from 56 deg to 10 deg while increasing the gain at 10 deg by about 12 dB. Of course, such a choke is impossible in the real world but the idea might have a grain of usefulness.

I wish Owen, VK1OD, was still posting. This would be right up his alley.


Title: RE: 43 foot verticals
Post by: K4SAV on November 27, 2012, 06:34:06 AM
Here's another idea. Given a 44' vertical, we could turn it into a 2x5/8WL phased collinear on 10m by installing a phase shifting coil at the halfway point. If we could come up with a phase shifting common-mode bead choke, would that work? Some ferrites are mostly inductive at certain frequencies.

For instance, if I take a 44' vertical and install an EZNEC load of 0-j400 ohms at 22', it lowers the take-off-angle from 56 deg to 10 deg while increasing the gain at 10 deg by about 12 dB. Of course, such a choke is impossible in the real world but the idea might have a grain of usefulness.

I'm not sure that I agree with your numbers for the reactance needed.  (The reactance will depend on the details of the antenna construction and I think it will require a positive reactance.)  But that's not the point. 

For a phase shift network made from a core, I doubt that you will ever find a core(s) with low enough loss because the voltage across that core will be very high (maybe 500 volts at 100 watts, and 1500 volts at high power).  You don't get much inductance per turn with powered iron cores (which you will need for high reactance and low resistance) and for this application you are probably thinking a single turn per core.  That would probably require hundreds of cores.  Multiple turns on a core would very quickly exceed the maximum flux for the core.  It would be much easier to just add an air core coil or a phasing line.

I wish Owen, VK1OD, was still posting. This would be right up his alley.

Yes, I miss Owens comments too.  He is a library of information.

Jerry, K4SAV


Title: RE: 43 foot verticals
Post by: N3OX on November 27, 2012, 07:34:40 AM
Quote from:  link=topic=86565.msg635755#msg635755 date=1353836283
This becomes a lot easier if the radiator is smaller diameter.  For a half inch diameter radiator, a quick check shows that you could get 5K ohms with about 15 lbs of beads (based on some beads I have in hand).  With a skinny wire as a radiator, you would only need about 1 lb of 1 inch diameter #75 beads.  Anyone for designing a ferrite tuned vertical?

Are you distributing things over the length of the wire that they'd occupy in the model? We might want to be little careful not to completely trust a single EZNEC load for long bead chokes in high impedance areas.  For an extreme example of the weirdness that can happen because of displacement currents, take a look at this.

I was doing some coil Q tests using the method described here:

http://n3ox.net/tech/coilQ/

I became concerned about common mode excitation of the coax to the bottom plate of that apparatus; after all some small "antennas" are built like that :)  But every time I added a choke, whether beads or multiple turns through a core, I found a substantial measurable increase in the measured resistance of the LC circuit; equivalently a sharp reduction in the number I was getting for the coil Q.  The maximum attenuation I could achieve was greatly reduced. The absolute weirdest part came when I removed the bead choke from the coax feedline I was shorting to do the measurements; I simply attached it to the plate with the other end dangling in the air and measured a similar increase in the measured resistance of the "coil!!"

So I re-rigged and did some tests.  I removed all metallic connections between the outside world and the plate on one side of the coil/cap LC circuit.  I put the LC circuit in parallel and coupled to it with an inductive loop to my transmitter.  I attached the choke to the plate with the free end dangling.  That setup looked like this:

http://n3ox.net/files/chokeprob/setup_ann.jpg

I adjusted the coupling loop and LC resonant frequency for a good match, and applied 100W.

I have access to a thermal camera and took a picture after a short time:

http://n3ox.net/files/chokeprob/IR_Choke.png

The coil gets warm and the choke gets warmer, but not uniformly (this is probably less power dissipation in the choke than in the coil because of lower heat capacity, mass, and cooling).  The main weirdness here is that the choke is attached to nothing at all at the far end.  So the "circuit" causing current flow through the choke is all displacement current, and it is apparently distributed along the choke... you could kind of draw a circuit like this if you wanted:

http://n3ox.net/files/chokeprob/beadcirc.jpg

I made a lumped model to understand this a little better (though keep in mind that b/c of the reduction in current along the length the choke impedance R+jX in this model doesn't exactly translate to the string of beads).  I assumed a lossy inductive choke coupled across the coil with a small capacitance.

http://n3ox.net/files/chokeprob/circ.jpg

In this particular case, with a super strong electric field due to the high Q tuned circuit, the choke that you'd need to have to avoid perturbing the circuit is really extreme.  Here's the peak parallel resistance of the circuit above as a function of the choke impedance:

http://n3ox.net/files/chokeprob/R_chokes.png

Now, a long wire antenna isn't nearly as harsh of an environment as this: the electric field is not nearly as strong and if you put a 5000+j5000 choke at the "end" of a long wire section it's not going to affect the overall antenna losses as much as it does a very low loss tuned circuit.  Plus the wire on the other side will have some effect.  But the reason why I bring it up in the first place is that I wouldn't be surprised if a long string of beads in a high impedance part of an antenna has a substantial variation in heating along the length and probably ends up with a different effective choking impedance.

It's possible that this simply isn't relevant outside of this extremely high Q tuned circuit environment with hugely concentrated fields, but I wanted to mention it anyway.  I haven't looked much at models, but playing around with ten 500+j500 loads distributed over a couple feet in the middle of a 43 foot wire turns up some situations with very uneven distribution of dissipation in the individual sections.



Title: RE: 43 foot verticals
Post by: K4SAV on November 27, 2012, 02:27:44 PM
But the reason why I bring it up in the first place is that I wouldn't be surprised if a long string of beads in a high impedance part of an antenna has a substantial variation in heating along the length and probably ends up with a different effective choking impedance.

I didn't do an actual design Dan, especially since it didn't seem to be a good solution for a multi-band antenna.  I suspected that there might be a problem with a long string of beads, but the solution to this problem was left as a exercise for the student. :D  That's why I asked if anyone was interested in doing a design.  It didn't seem to be worth the effort for me because I didn't think the solution would yield anything anyone could build.  Power limitations will be a problem too.  The voltage across the choke will be very high and that can very easily cause the core flux to exceed the maximum ratings for the cores.

Jerry


Title: RE: 43 foot verticals
Post by: N3OX on November 27, 2012, 05:35:50 PM
  It didn't seem to be worth the effort for me because I didn't think the solution would yield anything anyone could build. 

That's true. 


Title: RE: 43 foot verticals
Post by: KE2TR on December 04, 2012, 09:12:52 AM
I installed a modified S9 43 ft vertical and laid a bunch of radials into the ground, used a 4:1 Unun and the antenna worked real nice on 20mtrs were it was a 5/8ths wave vertical but on the higher bands its take off angle was too high and on 40ty and 80ty there was way too much loss. I will end up tunning it just for 20 and let it be.
Jim


Title: RE: 43 foot verticals
Post by: W5DXP on December 04, 2012, 11:32:48 AM
I will end up tunning it just for 20 and let it be.

You can improve the 20m efficiency by installing a matching network at the base - probably just a tapped loading coil.


Title: RE: 43 foot verticals
Post by: K0OD on December 04, 2012, 02:27:01 PM
Quote
"on 40ty and 80ty there was way too much loss."

Unless you're running like a mile of coax, loss on 40-meters should be microscopic. How are you determining the loss there?

I use my 43 footer all the time on 40 and it works as well as a 1/4 wave vertical or perhaps better because it's taller than obstructions such as our home.


Title: RE: 43 foot verticals
Post by: KH6AQ on December 04, 2012, 04:44:37 PM
43' vertical article

http://www.eham.net/articles/21272


Title: RE: 43 foot verticals
Post by: WB6BYU on December 04, 2012, 05:20:25 PM
And here is VK1OD's analysis of losses:

http://vk1od.net/antenna/multibandunloadedvertical/index.htm



Title: RE: 43 foot verticals
Post by: K0OD on December 06, 2012, 05:48:37 AM
The poster who bashed the performance of these verticals on 40 has disappeared.

Links in the previous two posts suggest that 43 foot verticals have ESPECIALLY low losses on 40 meters unless fed with extremely long runs of poor quality feedline.  

Mine is 30 feet from my one-story home. I've used it for DXing, contesting and rag chewing for 4 years now. Using a 43' vertical solely for 20 meters is a waste of an antenna that's quite competent on 60 thru 15, and decent even on 80 and 10-meters.


Title: RE: 43 foot verticals
Post by: W5DXP on December 06, 2012, 06:10:31 AM
Links in the previous two posts suggest that 43 foot verticals have ESPECIALLY low losses on 40 meters unless fed with extremely long runs of poor quality feedline.  

A 43' vertical has a feedpoint impedance of around 100+j200 on 40m. A base-mounted autotuner, like my SG-230, would have very low losses with that feedpoint impedance and provide minimum (matched line) coax losses. It's hard to beat an autotuner at the base of these non-resonant length verticals.


Title: RE: 43 foot verticals
Post by: K0OD on December 06, 2012, 07:04:51 AM
A remote tuner is a very pricey way to go for hams running >100 watts. At least the cost is coming down. I've given it some thought. I'm not comfortable leaving such an expensive item outside. Also, I've heard plenty of complaints about the durability of remote tuners. OTOH, my in-shack Dentron MT-3000 is going strong after 35 years.

On 160 a remote tuner would be a huge benefit (on transmit only) , but so would clipping on a simple wire top hat or "L" wire. On bands higher than 80, the advantage of a remote tuner is negligible if the feedline is short.   

Any thoughts on this new remote tuner from MFJ? 
http://www.dxengineering.com/parts/mfj-998rt


Title: RE: 43 foot verticals
Post by: STAYVERTICAL on December 06, 2012, 12:53:46 PM
+1 for a remote base mounted tuner.

Put it in a waterproof case, and it will last indefinitely.
Even so called weatherproof tuners will benefit from this treatment.

I have used remote ATU's for seven years and sometimes I have to replace the case I enclose them in, but never the tuner itself.
Even some retrofitted remote tuners I have modified from coax type tuners are not a problem.
If you fit them in a watertight case, they will last as well as being in the shack.

I recently took one in for a basic clean, and it did not look any different to a new one I had recently acquired.
So, don't settle for the case it came in, give it an extra layer of protection and it will last a long long time.

The days of having to battle SWR losses on feedline coming from a multiband vertical antenna should have been left behind many years ago.
The VK1OD link which 6BYU gave shows that feedline losses are a major player in system losses with this type of multiband vertical.
These can be eliminated with a remote antenna tuner, so gaining you many dB which would otherwise have to be provided by an amplifier.

Remote ATU's are not that expensive these days, and it is hard to overstate the benefit of pressing the button and having a low feedline SWR.
I read time and time again about hams having matching nightmares, when it could be so simply and efficiently solved.
In addition, a good remote ATU can be used with open wire feedline to other types of antenna's, so they are extremely versatile.
We can then concentrate on the antenna, and forget the matching nightmares.

73 - Rob


Title: RE: 43 foot verticals
Post by: KE2TR on December 06, 2012, 06:04:49 PM
I will end up tunning it just for 20 and let it be.

You can improve the 20m efficiency by installing a matching network at the base - probably just a tapped loading coil.
I used 8 turns of #12 around a 2" form about 1.6" long at the base and a balun design 4:1 Unun, loads on 20 mtrs. with a 1.2 swr at 14.2mhz and 1.5 at band edges. I did shorten the vertical down to 41.5' which would be 5/8 on 20 at 14.2mhz, it still loads on 75 with the tuner in line but a 35' inverted L with 2 gull wing radials spanks it on that band but it realy does well on 20 mtrs (there's a bunch of radials in the ground and added some 20 mtr radials as well).
Jim


Title: RE: 43 foot verticals
Post by: KE2TR on December 06, 2012, 06:18:22 PM
I have two 1/4 wave verticals up for 40mtrs and I have removed one just to compare with the 43' vertical, the monoband vertical is always 6db  better on tx and sometimes more of rx. Sorry my real world comparo's speak volume from what I have seen and it always shows up on DX but on 20 it kicks some but. BTW the two 40mtrs vertical array is12-15db better on everything, tx&rx. Makes me think what two would do on 20!


Title: RE: 43 foot verticals
Post by: WD4ELG on December 07, 2012, 04:00:15 PM
Thanks for posting those results.  Definitely expect 2 x verts phased over single 43 to be better.

Wondering about 20 meters, where a directional horizontal antenna should blow the verticals right off the map.  However...it would be interesting to see....since the vert would be very low angle of radiation...and the horizontal antenna would need to be very high (above half wave) to get that...plus up higher the horizontal antenna would have secondary lobes at higher angles (which is why the big guns phase them...to eliminate those higher lobes).


Title: RE: 43 foot verticals
Post by: KA7NIQ on December 07, 2012, 10:13:34 PM
Here in Florida, you see an awful lot of these 43 foot S9 Verticals, mounted on chain link fences w/o any additional radials. The fiberglass S 9 Verticals seem most popular, because some Hams here in Florida have power lines nearby.
They seem to do ok with these antennas, especially on 20 and 40 meters.
One Ham I know has one of these mounted where 4 chain link fences come together.
He used the MFJ current sensing meter to make sure his chain link fences were seeing the full current they should have, and had to electrically enhance (bond) some parts of the chain link fence. He uses an LDG high power auto tuner at the base of the antenna.
He only has a small amplifier, but on 40 meters, well inland from any salt water path, he blows smoke into Italy on 40 meters at night. All from a smallish city lot, east of Tampa.


Title: RE: 43 foot verticals
Post by: K0OD on December 08, 2012, 05:11:27 AM
If a 43 footer works terribly on 40 meters, something else is going on.

It's hard to follow your antenna tests or know when they were conducted. Likely there's some interaction between the multiple 40 meter verticals you're comparing. Certainly your 1/3 acre QTH, with NINE yagis on two towers, isn't exactly a pristine antenna test range:

http://lists.contesting.com/_towertalk/2001-09/msg00034.html
http://www.ezoom.net/images/lotsayagis.jpg
http://www.qrz.com/db/KE2TR.


Title: RE: 43 foot verticals
Post by: AD5X on December 08, 2012, 09:02:35 AM
...Any thoughts on this new remote tuner from MFJ? 
http://www.dxengineering.com/parts/mfj-998rt

I did the review on the MFJ high power remote tuners for QST.  The unedited review is in the "Reviews" section on my website at www.ad5x.com.  After returning the tuners to the ARRL, I decided I really wanted one for my 43-footer.  So I got one.  I could have gone with the much less expensive MFJ-994BRT since I just run 500 watts, but I chose the MFJ-998RT since it is so much more "hefty".  R&L has the best prices I found.  Anyway, all tuners worked fine for me.  The only issue is that none of the remote tuners can tune the 43-footer on 160 meters without adding external inductance (see November QST or the 160M extender article in the "Articles" section of my website)

Phil - AD5X


Title: RE: 43 foot verticals
Post by: K0OD on December 08, 2012, 07:08:26 PM
Hey Phil I was reaching for my credit card when I noticed that very costly MFJ-998RT KW remote tuner is spec'd to handle SWR's only under 32 to 1. 43 footers have SWRs much greater than 100:1 on 160 and perhaps more than 32:1 on 80.


Title: RE: 43 foot verticals
Post by: AD5X on December 08, 2012, 07:42:20 PM
Hey Phil I was reaching for my credit card when I noticed that very costly MFJ-998RT KW remote tuner is spec'd to handle SWR's only under 32 to 1. 43 footers have SWRs much greater than 100:1 on 160 and perhaps more than 32:1 on 80.

It'll tune the 43-footer on 80 meters, but not on 160 meters.  See my article in the Nov QST, or in the "Articles" section of my website that shows my add-on inductor for 160 meters.

Phil - AD5X


Title: RE: 43 foot verticals
Post by: K0OD on December 08, 2012, 08:30:59 PM
Yes, I'm familiar with your excellent material. I've used a properly baseloaded 43' vertical on 160. Frankly, it's a lot of work and cost and the result still isn't good on 160. Using 100 watts, I eked out a few Qs with big gun European stations. Now without the baseloading, Qs beyond 1,000 miles were nearly impossible.

I had much better luck with a wire L years ago: 140' of wire tossed over a 50 foot tree with the end anchored to another tree. Cost about $5 and was invisible. I understand that not everyone can get a wire up 50'.  


Title: RE: 43 foot verticals
Post by: KE2TR on December 09, 2012, 10:46:48 AM
In regard to testing the 43ft vertical on 40 I have down about 30 33ft radials and also a bunch of 18ft radials as well plus its tied to about 100ft of chain link fence. When I compared the two verticals on 40mtrs I used just one 1/4 wave vertical with 2 elevated radials, local qso's were not as big of a difference but on DX it showed up more when using the monoband vertical over the 43ft vertical. On 75mtrs the 30ft inverted L (this is a coaxial inverted L) has a lower noise floor and is an all around better antenna for both local and DX. Were the 43ft vertical shines is 20mtrs., I had up a 20mtr delta loop and it spanks that antenna on everything, maybe cause its 5/8 wave and according to theory 3db of gain, I don't know but its a real good antenna for that band. I am not saying that its a bad antenna but its a compromise just like trapped verticals and anytime you compare a monoband antenna to either trapped or 43ft vertical, the monobander will do better so its what you want in total system performance is the bottom line. Maybe if you just want one antenna at your qth it makes a good compromise antenna but above 17mtrs the take off angle gets a little on the high side but on the lower bands it makes for something that will get you on the bands with a decent signal. BTW all the antenna feedline's are with RG-213, no RG8X.
Jim
KE2TR


Title: RE: 43 foot verticals
Post by: W5DXP on December 10, 2012, 05:36:41 AM
Where the 43ft vertical shines is 20mtrs., I had up a 20mtr delta loop and it spanks that antenna on everything, ...

If that's a full-wave 20m vertical delta loop, it should beat the vertical broadside at most elevation angles (if it is as tall as the vertical).


Title: RE: 43 foot verticals
Post by: K1DA on December 10, 2012, 08:37:34 AM
With regards to the long radiator problem on the higher HF bands, has anyone considered putting a sliding ferrite suppressor ring on the vertical?

I can't claim this is original since I saw this in some forgotten antenna book, but it may be one way of stopping having to lower the whole tube.
Perhaps some sort of flagpole pulley arrangement on the top and a ferrite ring free to be hoisted up and down.

I am not an engineer, so I am only surmising this could act as a sliding suppressor trap, electrically shortening the antenna.
It may be totally wrong technically, but perhaps some of the genius antenna guru's could comment on this sliding ring's effect.

Another thing I saw was that if you move a capacity hat down near the feedpoint of a vertical, very little radiation will be above the hat.
If a suppressor ring is not practical, could a sliding capacity hat do the same thing?
 
I am pretty busy at the moment with my own antenna experiments/building, but I will try it when I have some free time.

73 - Rob
  HyGain used stubbs to decouple lengths of the antenna on the HyTower, which is 52 feet high.


Title: RE: 43 foot verticals
Post by: K0OD on December 10, 2012, 08:46:13 AM
Jim [KE2TR], I'm still trying to figure out where your A/B antenna tests were done. You've moved a number of times according to your online info. Was this the location, apparently on the tip of Long Island surrounded by ocean and a ton of aluminum shown in this picture?  Your info says you had a "3 element 40ty at 72' "
http://www.ezoom.net/images/lotsayagis.jpg

[sing along] "If everybody had an ocean across the U.S.A..."


Title: RE: 43 foot verticals
Post by: KQ0C on December 10, 2012, 12:45:00 PM
I use a wire 43 footer next to a wire 24 footer. I use the 43 on 20-30-40-80 and the shorter antenna on the higher bands. Feed both with ununs. My feedline SWRs don't run all that high so feed line losses are manageable. Both antennas share a semi-decent radial field.

A remote SGC auto-tuner would be more efficient but I run higher power than they can handle.

At a different QTH I have the heavy duty Zero Five 43-footer which I top load to be an 80 meter monobander. These are really built beautifully. I do guy mine with the guy ring provided with that version of the antenna. It sees 100 mph winds a lot and has been struck by lightning at least twice.

But if you have trees why not just run a wire vertical.

And incidentally, if you run an inverted V with the feed line coming down a tree trunk that is pretty invisible too.



Title: RE: 43 foot verticals
Post by: KE2TR on December 12, 2012, 08:01:19 AM
That was two qth's ago back when I had my mini contest station and a small ton of yagi's on 1/3rd acre plot here on LI,NY, wish I had that station out here which is 15miles east of the old qth. Were I tested the 43ft against the 40mtr monoband vertical is my present qth, both qth's were are 5 miles inland from LI sound so I didn't get that extra 6db boost from a salt water qth. All I have up here is a pair of 40mtr verticals, the 43ft tuned for 20mtrs and a coaxial inverted L for 75mtrs, much lower profile then back then. When I had that station I was single so that kinda changes when you get married. That station was my dream shot and I am glad that I built it cause it played real well but its allot to take care of, now I keep it simple and easy.
The delta was at 35ft and I did take it down cause the vertical did as well if not better, the longer the dx path the better the vertical did over the delta.
Jim


Title: RE: 43 foot verticals
Post by: W5WSS on December 12, 2012, 08:31:55 AM
Kq0c I use three wire verticals 22ft 44ft and 66ft and a  hoist made of rope.

I hoist one of the three up and hold it taught.

I have pairs of elevated radials that slope down from the feed point.

2 per band 75m to 10m.

The feed point is just outside the shack window.

The auto tuner is just Inside the shack window.

A wander lead is used to ground the vertical wire to a ground rod.for safety during thunderstorm potential.

I can hoist up down and change vertical wire about 2 minutes.

The radials are isolated from ground and uses insulated anchors driven into earth.

I built this for a summer cottage in TN and loved it.

Three verticals and quickchange.