The AM Forum

I had a QSO this evening with KJ2P who was running 1kW into something called a TAK-tenna. He said he's very pleased and happy with it, he's had it for 2 years now and it does everything just as well as a dipole.

His signal was quite good considering how much QRM there was this evening, at least S7 background noise on 40m.

Does anyone else have experience with this TAK-tenna? Would it be good on 20m for transAtlantic QSOs?

http://www.tak-tenna.com/

73s, geo VE3GZB

Geo,

    A lot of folks weighed in on this one, and we never came to a consensus. There were those that wanted to explore how it might work, and there were those that insisted any radiation off the Tak had to be feedline radiation.

http://amfone.net/Amforum/index.php?topic=21991.0

Jim
WD5JKO

" Would it be good on 20m for transAtlantic QSOs? "

Probably not nearly as good as a 1/2 wave dipole that is horizontally polarized, more than 16 ft up and broadside to the target.

This is the lay of my QTH here. The only real place for a dipole is up on the TV mast.

A powerful windstorm caused a crack in one tree out front last year and it died, had to be chopped down. It wasn't very big anyway because the trees on this property are less than 30 years old, the old house and old trees were knocked down by a Tornado back in 85.

Another tree out back, this one about 20ft. tall that had it's trunk split off into three equal parts, is now just living with one part. The other two parts of the trunk were literally torn down by a heck of a wind storm just last week.

The tallest structure on the property is our old TV mast, about 35 feet high. THIS is where I want to put some kind of 20m antenna.

The TV mast is about 25, 30 feet from the CATV and hydro lines on the poles that run next to the property. See attached JPEG taken in the late summer a few years back when I was experimenting with an end-fed inverted L, barely visible in the photo, hanging off 1/2 way up the TV mast.

There's a clothesline pole at the corner of the property, near the eastern neighbour's house. The north leg of my current 40m inverted Vee is anchored to that clothesline pole.

The apex of the inverted Vee is suspended by a piece of metal clothesline which has been tossed over the Yagi and I pull on the clothesline when I want to hoist the current inverted Vee up, and I pull on the feedline (16 ga. audio speaker wire really, I'm running it as a balanced line out of my balanced line tuner and it works pretty good) when I want to pull the inverted Vee down to do something to it.

Of course our neighbours immediately to our north have the beautiful big tall tall trees because their property didn't get as damaged during the Tornado. But they're not fans of amateur radio and they don't want anything to do with antennas and whatnot.

People here like a nice looking community, not an antenna lab experiment in the back yard. My wife feels that way too but she tolerates my experimenting.

A good 20m antenna that sort of resembles a common VHF TV type Yagi would blend in well and not raise any eyebrows among the neighbours. But I can't put up a fullsized 20m dipole, the end of the dipole would be too close to those lines that run by the property, and loaded dipoles that can run 800W seem to be a challenge due to corona.

I don't know if any of this helps but it's what I've got to work with. I'm quite close to the CATV and phone lines, the TV mast is closer than farther to those lines as well, and I have neighbours to the north, east and west of me.

73s geo VE3GZB

Because the design is so unusual and the review comments are as mixed, I'd want to see some testing results compared to things I know about, like a 1/4 or 5/8 wave vertical, or a common ol' dipole. There are no such tests to be found, or that I could find.

More than one of the reviewers said it is tricky to tune and it's not unreasonable ascribe some of the negative comments to improperly tuned specimens because the design is unusual and most hams probably don't understand it. I don't claim to understand it.

I'd be as likely to swing a couple slinkys across the attic as to spend $0.12K on an antenna I don't understand well and has mixed reviews. I'd want the great performance that some of the reviewers claim, not the problems the others claimed.

A strict A/B test would be the thing to do and very simple with an antenna switch at the radio, right? But the manufacturer should be the one to do the tests and make the results freely available. Whether it's 'same as' the dipole or 10dB down, that does not matter when the customer has no space for a dipole and has to do 'something'.

Only what matters is the testing so people can know what to expect and make an informed decision when considering a small-space antenna. Even if the test were nothing more than several stations at various distances comparing s-meter readings or AGC voltages in an A/B test. If the feedline makes for part of the performance, so be it, as long as the rules for scientific experiments are adhered to, including documenting the setup.

It bugs me that so many manufacturers of unique items offer no scientific test results. They ignore even these high-school science rules:

Purpose of the Experiment:
What are you trying to find out? Rather than starting from scratch in putting together a plan for answering your questions, using library and Internet research help you find the best way to do things and insure that you don't repeat mistakes from the past.    
   

The Hypothesis:
Like an IF-THEN statement. Your upcoming experiment tests whether your hypothesis is true or false or provides certain data. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should repeat your experiments several times to make sure that the first results weren't just an accident.
   

The Experiment:
Experimental Procedure Documented
Materials List and equipment settings
Conduct the Experiment.
Once your experiment is complete, you collect your measurements and analyze them. This is the test of the hypothesis.


Result:
Data Analysis & Graphs
Conclusions
To complete your science project you will communicate your results to others in a report.

G,

look at this

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=21318

I'd also want to guy your existing tower .........   ( 10 meter "v")

klc

Geo, you have more space, compared to alot of other guys...any chance of putting up an inverted V, from the tower, equal on both sides, and fed with open wire line?...no traps, etc...?..

..tim..

The miniYagi looks nice! Wonder how much power it will handle? Will it handle up to 800W?

Our TV mast is anchored to the side of the house (anchoring is not visible in the photo).

Not shown in the photo as well, I am running an inverted Vee (I believe I stated so earlier) for 40m. The inverted Vee is oriented to transmit East-West.

I was running a dual-band inverted Vee (20/40m) and 20m operation was quite good for all speaker wire! QSO to England, Scotland, Slovenia and Ukraine was possible. But I ran into a problem with TVI on 20m. In the given layout in the picture, an inverted Vee for 20m places the ends of the antenna WAY too close to the CATV line, causing TVI as I infect the cable, shield and all, with RF. Even at only 120W.

40m generated no TVI off the same inverted Vee.

I've changed the 20m antenna to be a suspended dipole off the north leg of the inverted Vee now. But DX isn't as good.

I've added LP filtering to my transmitter and this has helped a lot, but when I run 800W on 20m, I will definitely need to put the 20m antenna up out of harm's way because the radiated power levels will be enough to cause TVI even at the fundamental frequency.

73s geo VE3GZB

Geo
 Here's a link from E-Ham
http://www.eham.net/reviews/detail/6775

Many are happy with this antenna.........I wished I wudda seen this when we visited the Philippines last year. The Ventenna vertical and the 5 radials was miserable
Build another tower 50 feet and mount it there. Your present tower is in use for the TV and you do not want Ham radio RF too close to that antenna. PLUS the TAK antenna might be very sensitive being close to other antennas.

No, we do not use that Yagi for TV reception. Yvonne needs closed-captions and the signal degrades entirely too much with only antenna type TV. We have Cable TV now, so the captions are clear.

The Yagi atop the TV mast is entirely unused now, this is why I want to put another antenna up there for 20m.

But we're still very close to phone, CATV and power lines so I can't put up a fullsize dipole.

73s geo

..there is a small antenna, built by TGM in Stratford, ON. it is rotatable, and i think it is 20-6 metres...there was one listed on the ontarioswapshop recently...it seems to me, the guy from TGM will be at the upcoming hamfests, one in june, and milton in july...check out his website...

..sk..

junk

I'm not an expert on antennas or antenna design, and I have not used this particular antenna, but it has been my experience that if it sounds too good to be true, then it probably is. Pretty much anything will radiate, even a light bulb or coat hangar.

Antennas can be efficient, broadband or compact. You can only pick two, and no amount of fiddling with weird geometries is going to allow you to have all three.

I personally stay away from gimmick antennas. They're all aiming for an impossible combination of attributes, and I have a hard time believing their claims.

As for eham reviews, those folks never met an antenna they didn't like. Just saying!  ::)

-Robert, K7ZMB

..geo..that TGM is still on the ontarioswapshop...look it up, phone or email the guy to see what he is asking...now, it wont perform like a full sized 20m yagi, guys are using them, in restricted space...

..btw...my offer for free wire, still stands...i'm thru your town quite often...as well, there is another ham in grand valley, cant remember his call..

..tim..

..sk..

Good antenna discussions for limited space on the UK ham forum http://www.hamradiodeals.co.uk/forums

Antenna discussion is moderated by Steve, G3TXQ, who is no slouch in antenna dom.   The UK guys are very fond of their Hexbeams and Cobwebs.  There as here wishful thinkers want verticals with few radials to work, etc.

Frank if he feeds it with RG-214 then it can be used for weak signal work.

Yea Mike and if he feeds it with a single wire and L network tuner he might actually work someone.

I'd put this thing in the same category as the E-H and Cross Field antennas that were supposed to have been miraculous and revolutionary for HF AM broadcasting.

A working model is claimed to have been built in Egypt, but despite conflicting reports on how well it works, no reliable technical data or statistics on its performance have been published, and the FCC has not approved its use as an AM broadcast antenna in the US.

For more information, do a Google Search (http://www.google.com/search?q=e-h%2C+cross+field+antenna&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a#q=e-h,+cross+field+antenna&hl=en&safe=off&client=firefox-a&hs=iOh&rls=org.mozilla:en-GB:official&prmd=ivns&ei=WFjRTZj5BMXJgQeQ3LTBDA&start=10&sa=N&bav=on.2,or.r_gc.r_pw.&fp=c4b94ef403c105f7) for e-h, cross field antenna.

Well, I finished the short (24 ft) Helical dipole and we put it up on the TV mast on Saturday.

Since then I've had 59 communication to on both 20 and 17m England, France, Belgium, Czech republic, Spain, I've had 58 QSO out to Russia and last night had a 56 QSO out to ZL3GS for the first time.

At the time I was running my linear only up to about 250W so I probably could have managed it "barefoot" too.

The young lad on the roof is my stepson who is very daring and very brave, especially when I pay him to saunter up there with the antenna.

I'm using speaker wire as my transmission line still.

73s geo VE3GZB

FB, OM.  Looks like you have entered a new whirl of antenna construction and performance.


Coupla things:

1) Keep an eye on the potential for wear on those plastic insulators from the steel wire. It may take a few years in the wind, but it could eat thru, depending on the tension, ice loads, etc.

2) The speaker wire is "balanced" unshielded feedline. Be sure to keep it away from the rotator control wire and ANY metal mast or house metal on it's full run to the rig.  When you finally get some coax, this requirement will disappear.


BTW, how did you get it to work on BOTH 17M and 20M with a low swr?  Did you have any trouble getting it tuned/trimmed in with the helical windings?

FB on all the new contacts.

T

Currently I have the feedline just hanging in the wind so to speak, so it isn't too close to the mast.

To tune it up, I have one of those fancy antenna measurement devices from MFJ. I started with having full number of small helical loops on the dipole, using 50 feet of wire per leg. Fastened it all down, took it up to the railing on the deck which is about 8 or 10 feet above the earth.

Then I started methodically snipping and shunting loops one by one until I got something close to what I wanted for self resonance, knowing that it will change once it's hoisted into the air.

It was just dumb luck that it happened to be able to tune up on both 20 and 17m. I checked this with the MFJ antenna tool before connecting it up to my tuner and sure enough I saw multiple resonant points above 14 Mhz, so I'm smiling!

The key of the thing was the availability of these 8ft long fiberglass military surplus poles and joining them together with well fitting aluminum sleeves, 4 pipe clamps on each sleeve and plenty of marine epoxy, then giving it a lot of time (couple of weeks) to set and cure.

The antenna insulators seen on the guy wires (aircraft cable, available at Home Depot) are ceramic, and they're latched onto the fiberglass with a pair of thick nylon tie wraps. There's not a lot of weight to these fiberglass rods and I wanted it to have a lot of give in the wind.

Only time will tell of course. I don't have a lot of dollars to put into a nicer antenna but this is just my first try.

The mounting plate that holds the horizontal poles to the vertical pole? That's a homemade job from scrap steel at the farm. Cut and drilled it, painted it, tried to make it as low drag in the wind as possible without sacrificing too much strength.

It isn't the best, but it does fit on the property without crossing the property line or getting too close to those darned high voltage lines.

When winter comes we'll see if it all comes falling down. Or in a strong storm. I'm hoping not.

73s geo VE3GZB

I talked with the owner of MapleLeaf Communications today, Bob Morton (VE3BFM) about this antenna I put up.

Bob is the one I talked with regarding different antenna designs you all shared with me here, then based on my budget, experience in antenna construction and space limitations he drew out the preliminary design for the helical dipole and I built it based on his drawings.

As far as multiple resonance goes, he thinks it's more than likely due to the proximity of the metal guy wires and their size. They may be acting as drone antennas, allowing resonance on other frequencies.

73s geo VE3GZB

Gee those fiberglas poles could build a loop or quad. You could make a loop for each band and feed it with coax or just 1 loop with open wire line.

It's tough enough to just keep these two dipole legs from sagging, and they are sagging just a little now when the wind throws them out of centre.

I'd hate to imagine trying to keep more of them aligned in some fashion!

Tall tall trees are what I really yearn for, but sorely lack.

Oh well!

get some black walnut saplings. They grow about 3 feet a year.
Another option get a length of pipe and add a mast to the tower. Then put up an inverted vee.

 Bought one two years ago,it's on my scrap pile,come get it. Tried but can't give it away,no one wants it. I heard the Collins Collectors Club endorsement of it was false also. :(