We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: T2FD Antenna  (Read 37850 times)

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #15 on: May 17, 2010, 1737 UTC »
"W7LPN thanks for your Emails:
Trust me, I've read them all.... Even ole Marty Jue..(XXX) notes of distain:...

The problem now is, all the advertisers who pay big buck$ with XXX, & XX mags to advertise their Antenna tuners have now threatened the ARRL/QST, and CQ to redraw or reduce their advertising if they continue to publish articles about T2FD, and WINDOM (tunerless) antennas.  ANY Antenna that does not use an antenna tuner that could be written about in these pubs are bad news for the leading Amateur Publications.  Cebik is now SK, but back when he wrote that piece, he was writing books for QST/ARRL.

For eighteen years, I was the digital editor of XX magazine, never missed a month writing my column.. sometimes several...  Then when I wrote an article about the T2FD, they refused to print it... then I wrote an article about the Windom.... suddenly I had some sort of writers disease... they would not print it either.

I was furious, as I had put a lot of time and effort into those articles (column). 

I gave them my "notice" and immediately stopped writing for them.  They got P/O'd and then one of the employees of XX (nameless), called and informed me WHY they would not print my articles about the antennas that did not need an Antenna Tuner....

Seems two of their biggest advertisers threatened to pull all their advertising dollars if they ever gave credence to any article(s) that took away antenna tuner sales.

It's a sad day when politics enters our hobby, and begin to dictate editorial policy… and the rank-n-file HAM suffers because of the all-mighty dollar.

Up until 1995, all the handbooks, HAM magazines, and league publications (Antenna Books) had articles about T2FD, Windoms and specific antennas that did not require an antenna tuner. 

SUDDENLY, all the Antenna handbooks, Annual Amateur Radio Handbooks.. and publications sold by the XXXX, XXX, or XX, took a noticeable difference in their hobby antenna related content and antenna information:!

ALL, I mean ALL reference to the T2FD, the Windom, and tunerLESS antennas was noticeably missing from these rags!
Here be side me, in my BOOK CASE are the last 4 years of ARRL Annual Handbooks.  Not a word about these antennas.

Add to that, I have the ARRL Classic Wire type Antenna Handbook; first Edition Copyright 1999 through 2009.
Here is a book that should be bulging with T2FD, Windom and other WIRE type antennas (that don’t need antenna tuners), alas… NOTHING!
I tried to make a big noise, but I was laughed at because I related this to some of the "powers-that-be" at the league, and XX.... they poo poo'd it and denied it no less.

I rest my case.

Now you understand why I don't advertise in any of these “Hobby Rags.”

Every chance they get, they'll have some of their cronies put something on an antanna review page in print, trying to discredit me.  I'm still here, and most of them are out to pasture.

AND now’ you know "The rest of the story !"

Have a great weekend."

Anonymous, but not too hard to tell who it is.

 


cmradio

  • Guest
Re: T2FD Antenna
« Reply #16 on: May 18, 2010, 0038 UTC »
Politics ::)

Peace!

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #17 on: May 18, 2010, 1559 UTC »
I have 2 of the B&W folded dipoles (T2FD type).  They both work much better than standard dipoles.  Out of the dozen or so antennas here, the folded dipoles are the 'go to' antennas most of the time.

Gee whiz, the local FCC office has one on their roof for their HF intercept!  They can't be THAT bad.  I agree with the author, if every ham and SWL tried a commercially built T2FD style antenna, tuner sales would certainly drop drastically.  I don't buy into the conspiracy theory, but it is possible I suppose.

One of my folded dipoles is about 9 years old, the other about 3.  The first was installed N/S and was just such an awesome performer, I couldn't resist buying the second one when I was able to install E/W.  Not a bit sorry about either purchase.  Would certainly buy again.

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #18 on: May 19, 2010, 0501 UTC »
Thank you for an honest real-time evaluation. I don't really care about whether anyone believes these antennas(T2FD & Windom) have been conspired against. I'm sure if I was the manufacturer and couldn't get a fair deal I would feel very different about it. If you occasionally get on QRZ forum look up antennas, limited space W7LPN thread. The so called experts have been bashing the t2fd for a few days. I'm relatively sure these "Experts" don't, nor ever have, owned a commercially manufactured T2FD. The truth as you have stated it needs to be known.

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #19 on: May 19, 2010, 1636 UTC »
That's exactly why I stay off of QRZ forums and other similar forums.  You stand a better chance talking reason into a CB forum than you do the ham ones.  Hams hear someone say something like "RG-8 is the best coax on the planet" and then they parrot that from that day forward.  They don't know, they have never done their own experiments, and 99.9% of them don't have the right test gear to do it right anyway.  Heck, 99.9% of them say "I put 1000 watts in, I get 999 watts out" and call it good.  What about receive?  What about induced noise?  What about efficient transfer of those precious few microvolts from the antenna to the receiver?  A 2-way conversation requires both stations to be able to copy each other!

The hams are all 'experts' because they have a license.  Big whoop.  If I have a driver's license, does that automatically make me an expert driver?  No, of course not.  Same thing.

I happen to be a 'real' RF engineer, and have been a radio and TV Chief Engineer for 30 years.  I find it amusing that a ham with no engineering education or background will argue a basic point with me.  I have actually had hams with Extra licenses tell me they know more than me simply because I have not upgraded from General.  Seriously!  In an effort to keep my blood pressure low, I avoid those ridiculous forums.  All hambones can disappear forever as far as I'm concerned sometimes.  90% of hams really repulse me.  I suggest you adopt the same policy, life is so much more peaceful when you avoid the hambones.

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #20 on: May 19, 2010, 1659 UTC »
By the way...  I just read your thread on QRZ.  The two 'experts' that replied are showing their lack of knowledge, and a sharp prejudice for something they have not tried themselves.

If they had a shred of knowledge in this department, they would know that a balancing resistor on the OPPOSITE side of a folded dipole does not absorb "half the transmitter power" at all.  If that were true, that resistor would blow up every time I run 1500 watts on CW.  In fact, at most, the resistor will absorb 1/4 of the transmitter power if the antenna is that far out of resonance on my chosen operating frequency.  The other 3/4 is radiated with a very small amount coming back (<10%).   Most of the time, the balancing resistor isn't doing very much.

And, none of those jerkoffs even considered the receiving characteristics of the antenna (which is what it was actually designed for).  The balancing resistor keeps the elements in perfect balance all the time in relation to the feedpoint, and THAT does a very effective job of canceling out local noise.  In addition, at MOST, the balancing resistor might cause a 3 dB drop in signal (1/2 an S-unit).  Most of the time, it absorbs little, if any signal.  Almost all signal is fed to the feedpoint through the folded dipoles because of the slightly lower resistance at the feedpoint that at the balance point.  That is why for a 500 ohm feedpoint, you use a 540 to 600 ohm resistor in a terminated folded dipole.

I could go on and on, but I have a job, and a life.  Those 'expert' pinheads need one of each too. 

See?  Hams really jerk my chain! 

73, TS

Offline Seamus

  • Full Member
  • ***
  • Posts: 140
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #21 on: May 19, 2010, 1837 UTC »
About the only thing I keep my (extra) license active for these days is to keep people from grousing about the legality of my data and video links.  Enough hams can't cope with the idea that someone one third their age is allowed to play with "their" radio waves, or just might actually know something about RF that it almost isn't worth even listening around the bands anymore, let alone transmitting.  If you can manage to find someone who doesn't go on about how you "can't be a REAL ham because...", then about all that's left for them to talk about is their medical problems.  Beyond that, it's "call, signal report (always an inaccurate 5x9), weather, 73".

Just last week, one of the local FM repeaters was all abuzz with people offering their valuable opinions on which coax a new ham should use to hook up his 2-meter ground plane.  One of the "experts" - I know he was an expert because he mentioned several times that he's been a ham for almost fifty years now - repeatedly told him that you didn't need to worry about coax line loss.  It was unimportant, he said, because as an example, he's got 10 or 12 dB loss on his antenna, and "you can't hardly even hear a twelve dB sound if you're tryin'".  Even so, he said that he just makes up for it by talking louder into the mic, and everyone can hear him just fine (his audio was clipping pretty badly, actually).  The saddest part was, NOBODY contradicted him; several even agreed wholeheartedly.

Other "wisdom" I have heard discussed on the radio recently:
  • RF radiation and ionizing radiation are the same thing (because they're both called "radiation", you know).
  • There's no difference between the different types of coax - it's all just price.
  • SWR doesn't matter with modern radios - they can pump full power into any kind of antenna (no mention of automatic power reduction when high SWR is encountered).
  • You've GOT to have an SWR of 1.1 or less in all cases, or you'll burn up your finals within minutes.
  • You can't use a computer and a radio together because they'll blow each other up.
  • You can't build your own antennas or radio gear, because the people who make commercial units have access to "special wire", materials, and "design computers" to make them work.
  • Regular horizontally-strung dipoles are non-directional (all cases, regardless of frequency or height above ground).
  • It's impossible to operate HF from a moving vehicle, because the motion will cancel out the longer wavelengths.
  • You can't polarize an FM signal (apparently, horizontal, vertical, RH and LH circular polarization are all just a bunch of hooey, despite demonstrable effect).
  • The one biggest thing that can make or break a hamfest is having enough electric scooter carts available for rent (out of all of the above, this is the one item I believe to be true).

Listening to the local repeaters can be hilarious at times, but it doesn't take long before it just becomes too depressing to bear anymore; my dual-band mobiles are most often used for listening to the local EMT dispatchers these days.

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #22 on: May 19, 2010, 1929 UTC »
Thanks again. I am not an RF engineer. I know a few of them & they make more sense than any of these "Hambones" you speak of. When he was criticizing the effects of the non-terminating resistor, it sounded like puffed up BS. Sooner or later you can recognize the truth and the level heads in a discussion. Tahnks , & 73. 

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #23 on: May 20, 2010, 1544 UTC »
First of all, Seamus- You literally had me laughing out loud!  I actually spit on my screen when I read the part about the electric scooters!    Man, that was funny.

W7LPN- Yes, you are correct.  It is pretty easy to spot the 'real' experts sometimes. 

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna- Please reply
« Reply #24 on: May 20, 2010, 1711 UTC »
I'm searching for the truth. Please read.  :)

 W8JI
Ham Member
        
Join Date: Oct 2003
Posts: 2,853
Send a message via Yahoo to W8JI
Default
Any one additional comment you can pass back to "tube shortwave" about this:

"If they had a shred of knowledge in this department, they would know that a balancing resistor on the OPPOSITE side of a folded dipole does not absorb "half the transmitter power" at all. "

That wasn't the statement at all. He isn't even honest enough to quote someone accurately.

The statement I made (it is in black and white here on the Zed, so there is no debating he misquoted) is the resistor sometimes dissipates less than half of the power applied to the T2FD antenna, and on other bands it dissipates much more than half the applied power. Nothing worse than a critic who fabricates the very statements he is openly critical of.

He goes on to say:
"If that were true, that resistor would blow up every time I run 1500 watts on CW. In fact, at most, the resistor will absorb 1/4 of the transmitter power if the antenna is that far out of resonance on my chosen operating frequency. The other 3/4 is radiated with a very small amount coming back (<10%). Most of the time, the balancing resistor isn't doing very much."

That's clearly wrong, as any analysis or measurement has shown. What "tube shortwave" is unaware of is the owner of Amp Supply found that antenna design in some publication and decided to build it commercially. I believe he eventually cooked up a deal with B&W to buy the "design" of that, and a terminated V, antenna. The original matching transformers were the filament chokes from amplifiers, wound at Prime Instruments.

I actually directly measured the dissipation in the resistor and it was pretty high overall.

There is considerable mutual coupling between the dipole half with the resistor, and the dipole half with the feedline. Anyone who knows anything about antennas understands mutual coupling of two very long wires (90 feet or so long) spaced a few inches apart is extremely high, plus the ends of the wires are directly connected. The resistor is, for nearly all practical purposes, directly connected across the feedline.

The power division depends largely upon the unterminated impedance at the feedpoint. On bands where the antenna is a conventional half-wave or 3/4 wave dipole length, that impedance is low and the resistor has limited effect on the system. On bands where the feedpoint would have a high unterminated impedance, the resistor soaks up most of the energy.

This is why the SWR stabilizes. What would be a terrible SWR on some bands is reduced by diverting energy into the resistor on those bands.

When testing the antenna as a consultant doing work at Amp Supply, I built an antenna at home and ran the "resistor" side through ladder line to a dummy load. I had an RF current meter in series with the load, and measured load current. I still have the huge resistor I used here, I use it as a dummy load for testing high impedance balanced systems. The measured result was basically as LB Cebik and many others have analyzed and published.

If you search the web you will find many articles telling exactly what the T2FD antenna is, and what it is not.

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #25 on: May 21, 2010, 1652 UTC »
I bought it! Thanks guys. I saw no reason so many positive reviews(unsolicited w/o monetary gain) would exaggerate or lie about favorable antenna performance. I think Buck called it right. http://www.buxcomm.com/catalog/index.php?main_page=product_info&cPath=45&products_id=2184&zenid=qj0ragan0h62c260r6lvhbbsf3

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #26 on: May 22, 2010, 1531 UTC »
Well, thank you for sharing.  However, I am not about to engage in an argument across boards with someone.

Just FYI (for you, not him)- You cannot compare real field and design experience with a guy who just repeats what other people write and calls it 'fact'.    Perhaps his non-resonant antenna was being influenced by outside objects or too low to the ground.  Or, perhaps his lab conditions were less than ideal for a non-prejudiced outcome.

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #27 on: May 22, 2010, 1630 UTC »
I agree completely. Some folks quote technical mumbo-jumbo and have never used the antenna to which they are criticizing. Buck Has one up & has used it for years. The only reason for posting quotes is to sift through the garbage & get to the facts, which I believe I've done. That's why I went ahead and purchased this antenna. I'll know for myself within a couple weeks whether it will operate as advetised here at my QTH. I understand good earth, poor earth, salt water, grounding & reflection, so I'm no ostrich. I will understand some or most of the why's or why not's. 

Offline Tube Shortwave

  • Full Member
  • ***
  • Posts: 115
    • View Profile
Re: T2FD Antenna
« Reply #28 on: May 22, 2010, 2333 UTC »
Well, it will be very nice to hear how it works for you.

You just have to love hams that think they are SO much smarter than us actual RF engineers.  It's kinda cute.
« Last Edit: May 25, 2010, 0257 UTC by Tube Shortwave »

Offline W7LPN

  • Newbie
  • *
  • Posts: 13
    • View Profile
    • Email
Re: T2FD Antenna
« Reply #29 on: May 23, 2010, 0501 UTC »
A fellow ham friend is an ex-military, then commercial RF engineer for 40-50 years, and I trust his judgment implicitly. He doesn't have to prove a thing, has been on the local ham clubs board of directors, or a welcome guest at tech meetings for decades. working at a career for 8+ hours a day for nearly 50 years trumps a test you can take 100 times, on line, to practice the right answers, while comprehending nothing, every time in my book.