Did anyone see the plywood box antenna at Nearfest?

[KF1Z]

How does one measure "Amazing performance!  ?

Last night, I downloaded a new update to my SDR receiver...

Fired it up, and there on 3885 were Bob k1kbw, Bill  kc2ifr, and several others...

All were over s9,  though Bob should have been stronger, so I thought the band was long.
It was after 10pm. maybe almost 11p.

After listening for a few rounds, I came to the realization that there was no antenna connected!

There had been t-storms earlier, and the coax was disconnected outside, and inside, and the Ant switch was on the dummy-load.

4 feet of rg-8u, to the switch, then 2 feet to the "bird"  military type dummy-load.

I thought the dummyload acted great as an antenna!

Now, If I had tried calling them, I doubt they would have heard me, but sure was working ok fine for RX.

Replace that 6 feete of coax, with wide-spaced feedline, and I bet if would give Amazing Perfomance!

 

[W1AEX]

It's pretty funny how well a dummy load can apparently hear and transmit. I have a friend I chat with on 75 meters frequently, who is about 50 miles away. He is usually 50 to 60 over, but now and then I will hear him call at S-2 or S-3 when he forgets to switch from the dummy load. I guess there's enough incidental coupling across switches and lengths of coax to radiate a couple of hundred milliwatts. As I recall, the Maxx-Com company actually marketed this with their "solid-state-no-moving-parts-antenna-tuning-device" that you installed up at the antenna feedpoint. Just a big dummy load with attachment points for your wires of any length. They must still be laughing about that one...

[K6JEK]

Let's chip in, buy one, and give it to Tom to play with.   He could compare it not just to a dipole but to all manner of crazy things. 

How could he refuse a present like that?

[WA1GFZ]

We had that conversation with the inventor and suggested Tom buy a bunch of them to hang between two towers and phase them. This could generate such a concentrated beam of energy that tower legs could melt running AM in old buzzard mode.

[Opcom]

Maxx-Com is gone.. or has no apparent website. Making an antenna or matching box that is essentially a dummy load has been very popular with many entities. The government loves them becaue there is no tuning involved.

I have a navy VHF antenna that is rated 1KW from 108 to 175MHz. It is in the shape of a cylindrical radome about 10" diameter at the bottom abnd 6" at the top. Inside is a copper pipe that goes straight up, makes a 180 degree bend, and comes straight down to terminate into a high power 100 Ohms resistor. very wide. RX is 3-6dB down over a 5/8 wave vertical on 2M.

Then there is the B&W no-tune NVIS dipole. It uses a balun to match the 50 Ohm coax to it, and the wires go out 50FT on each side, drop down about 18", then come back to the midle into a quite large 600 Ohm resistor.

Max-com was just selling the balun and resistor and the user supplied the wire.

[K5UJ]

Interesting news but it sounds like the inventors have no illusions about this taking the place of a full size decent antenna, so kudos to them for at least not trying to sell with exaggerated bs marketing like a few dozen ham companies over the years (few dozen?  maybe more).  

With 100 w. a good antenna on 40 meters say, should average signal reports of around 20 dB over S9, after making multiple QSOs around N. America over the winter months.  Higher sig. strength even better.  Everyone probably remembers the now sort of famous "everything works" article in QST about 8 years ago by the Force-12 guy (can't remember his name).  A light bulb works.  

The thing to do to evaluate this antenna is put up some kind of standard reference antenna, say a 1/4 w. vertical over 60 radials and conduct field strength measurements with a FIM at a constant distance in several directions with a constant power RF delivered to the feed point.  Then do the exact same thing with the AIB controlling for everything as much as possible so the only variable is the AIB.  Then you will know how much RF in uV per meter it is getting into the air vs. the reference antenna and you will have some bankable information removed from propagation and guys looking at wildly calibrated S meters.  ARRL should do something like this with every antenna made for hams but they won't, maybe because it might hurt ad revenue  

[Opcom]

Does the ARRL have the antenna farm and equipment to do tests like that? seems like they would. Well i hope the plywood box antenna really does work. It would be a benefit to those that can't put up big antennas. The reception of signals is what matters most to me and I've tried every whacky idea there is, including running a piece of wire 4 times around the walls of the room near the ceiling, each "turn" about 2" from the next. It did work, but not well, and it picked up every noise and garbage from every wire in the house. The boogler alarm is the biggest offender.

I was not gainsaying the inventors of the new antenna. I was adding my rant o the Maxx-Com matcher and comparing it to other products.

[K5UJ]

No problem; ARRL may not have space now (they used to have W1AW tx with a rhombic but I think they took that down and sold the land) but they could do something with a moderate amount of land.  A reference vertical need only be a wire held up with a balloon on a calm day and the radials can be simply laid out flat on the ground for one day of tests.   Take a few readings in six equally spaced on the compass locations all 1 Km from the antenna.  Do the same thing with the AIB the next day.  You can drive around with a FIM in a car and get out and take readings at the right GPS determined spots.  Fudging a bit to avoid trespassing is okay--it's not a broadcast proof of performance.  If they need land and money they could shut down and sell W1AW.  Evaluating antennas in an authoritative way would be a way bigger service to hams than W1AW is now.  When was the last time you listened to anything W1AW transmitted? 

Speaking of mystery things in a box, a few years ago some guy at Dayton was marketing an improved and modernized WRL Globe King.  It was supposed to be the ultimate ham AM transmitter.  He wanted around $4000 for one.  There were one or two issues of QST that had half page display ads for this thing.  I think only one was made and he had it at Dayton under shrink wrap and he wouldn't let anyone see inside the cabinet.   A year or two later some competent technician got it in to his shop somewhere in Calif. to make it actually work as a transmitter and he destroyed it in an eHam review--the facts made it obvious the whole thing was a complete sham.

[Steve - WB3HUZ]

Maybe the AIB guys should hook up with the AM-VA guys.

http://www.am-va.com/index.htm

[The Slab Bacon]

Maybe the AIB guys should hook up with the AM-VA guys.

http://www.am-va.com/index.htm

Ground Permitivity?  ? ? ? ? ? ? 

[Steve - WB3HUZ]

That part is actually legitimate. I think they are using that term instead of the possibly more familiar dielectric constant term. The two are related. Dielectric constant is actually relative static permittivity (relative to the permittivity of a vacuum). Permittivity is a more exact or detailed way of describing the ground or any other material, but we in amateur radio most often use dielectric constant and over HF, it is sufficient.

[KF1Z]

yup, just spelled a little off...

From an online source.....................

"Permittivity, also called electric permittivity, is a constant of proportionality that exists between electric displacement and electric field intensity. This constant is equal to approximately 8.85 x 10-12 farad per meter (F/m) in free space (a vacuum). In other materials it can be much different, often substantially greater than the free-space value, which is symbolized eo.
In engineering applications, permittivity is often expressed in relative, rather than in absolute, terms. If eo represents the permittivity of free space (that is, 8.85 x 10-12 F/m) and e represents the permittivity of the substance in question (also specified in farads per meter), then the relative permittivity, also called the dielectric constant er, is given by:
er = e / eo
= e (1.13 x 1011)
Various substances have dielectric constants er greater than 1. These substances are generally called dielectric materials, or simply dielectrics. Commonly used dielectrics include glass, paper, mica, various ceramics, polyethylene, and certain metal oxides. Dielectrics are used in capacitors and transmission lines in alternating current (AC), audio frequency (AF), and radio frequency (RF) applications. ""

[flintstone mop]

Maxx-Com is gone.. or has no apparent website. Making an antenna or matching box that is essentially a dummy load has been very popular with many entities. The government loves them becaue there is no tuning involved.

I have a navy VHF antenna that is rated 1KW from 108 to 175MHz. It is in the shape of a cylindrical radome about 10" diameter at the bottom abnd 6" at the top. Inside is a copper pipe that goes straight up, makes a 180 degree bend, and comes straight down to terminate into a high power 100 Ohms resistor. very wide. RX is 3-6dB down over a 5/8 wave vertical on 2M.

Then there is the B&W no-tune NVIS dipole. It uses a balun to match the 50 Ohm coax to it, and the wires go out 50FT on each side, drop down about 18", then come back to the midle into a quite large 600 Ohm resistor.

Max-com was just selling the balun and resistor and the user supplied the wire.

During the Y-2K joke my company installed the Motorola ALE  radios to all of our Nat Gas storage facilities and pumping stations,,,spread out over several hundred miles. We even had a mobile ALE installed in an all terrain vehicle.
The B&W NIVIS antenna was an ok thing but used up a lot of real estate and was not that flat over the HF spectrum. The freqs assigned to us by the Feces were in the not so perfect part of the range of that antenna. And with SWR foldback it was a challenge to make contact all the time with band condx changing, but that was supposed to be the magic of the ALE system.
We only used the barefoot power of the radio.
A really nice radio that was not user friendly, but had great specs!!!
FRED

[flintstone mop]

Speaking of mystery things in a box, a few years ago some guy at Dayton was marketing an improved and modernized WRL Globe King.  It was supposed to be the ultimate ham AM transmitter.  He wanted around $4000 for one.  There were one or two issues of QST that had half page display ads for this thing.  I think only one was made and he had it at Dayton under shrink wrap and he wouldn't let anyone see inside the cabinet.   A year or two later some competent technician got it in to his shop somewhere in Calif. to make it actually work as a transmitter and he destroyed it in an eHam review--the facts made it obvious the whole thing was a complete sham.

He was a total RIPOFF. Many made orders and paid in advance and never received product.
FRED

[WA1GFZ]

many made orders? how many people would pay $4000 for a unknown rig.
I don't know anybody that stupid

BTW, I ran into the inventor of the wood box at his place of work. He didn't remember me but fed my tech a pile of crap about his invention. Tom and Huz were getting a demonstration of a tune up as I modulated his swr by moving in front of the antenna. He looked like he was trying to chase a chicken.

[KD6VXI]

Tom and Huz were getting a demonstration of a tune up as I modulated his swr by moving in front of the antenna. He looked like he was trying to chase a chicken.

Sometimes I wish this forum had a "like" button. 

That's too funny

--Shane
KD6VXI

[WA1GFZ]

Funny, you should have seen the car he drives

[Opcom]

well, did the secret wood box antenna work or not? If so how well? we will likely never know unless it gets a real honest test.

[Pete, WA2CWA]

Speaking of mystery things in a box, a few years ago some guy at Dayton was marketing an improved and modernized WRL Globe King.  It was supposed to be the ultimate ham AM transmitter.  He wanted around $4000 for one.  There were one or two issues of QST that had half page display ads for this thing.  I think only one was made and he had it at Dayton under shrink wrap and he wouldn't let anyone see inside the cabinet.   A year or two later some competent technician got it in to his shop somewhere in Calif. to make it actually work as a transmitter and he destroyed it in an eHam review--the facts made it obvious the whole thing was a complete sham.

He was a total RIPOFF. Many made orders and paid in advance and never received product.
FRED

Seems to me I remember someone telling me 30 to 40 were actually made (no way to confirm this) and delivered. At least one went to a New England state, at least one to someone in Long Island, and the rest scattered across the U. S. Given its history, there probably are not too many that will step forward claiming ownership of one.

[KB2WIG]

"    how many people would pay $4000 for a unknown rig.
I don't know anybody that stupid    "

We're all over the place.


klc

[KM1H]

Dave Ring, the other half of the team, told me that it turns out the coax feeding the box was doing the radiating and he got out of the project. Id suggested that and that he try some ferrite beads.

However during the Nearfest demo a bystander asked if he could do a quick test. The rig was on 75 and he hooked up with a net in VT and got a S9+20 report. Thats a hell of a lot of RF getting out of just 10' of coax on the ground. I doubt if a mobile rig next to him could have received a fraction of that report.

[flintstone mop]

"    how many people would pay $4000 for a unknown rig.
I don't know anybody that stupid    "

We're all over the place.


klc

OK Fine! I'm not looney.......there WERE people who had advanced orders and paid in full waiting. What was pictured were beautiful replicas of Globe King. There were reports that what was inside was pretty bad news.
Too good to be true
Fred

[K1JJ]

Except for the front panel pulling off the chassis when the rig was lifted up (sheet metal screws) - and the chassis collapsing under the weight of the transformers, I hear it was a well built rig...

T

[Opcom]

Where could I find a ready comparison with inside pics of the original GK and the 'repro'? Just so as not to make a dreadful mistake. I found the three original manuals on BAMA mirror. Have not found the repro's manual yet.

[W1UJR]

Maybe the AIB guys should hook up with the AM-VA guys.

http://www.am-va.com/index.htm

I loved this from the AM-VA site:

"One interesting and unexpected result of our AM-VA field test involved the cattle that were grazing on the pasture where our field tests were performed.  The owner of the cattle herd indicated that his animals grazing on top of our AM-VA installation increased in body weight and weekly body weight gain when compared to similar animals in different locations on his ranch.  We were surprised by this unexpected positive result, but then found an article in the IEEE Antennas & Propagation magazine (Volume 49, No. 4, August 2007) written by James C. Lin wherein Mr. Lin found this same result from the magnetic fields near 735 KV AC high-tension power-transmission-line exposure. One wonders if the use of the AM-VA in heavily populated communities will have a similar health benefit to the local community living near the antenna.
 
With our initial tests results in, our next step will be to formally file the test results with the FCC and to ask for approval of this new technology.  We hope to have this accomplished by the end of the year and will post updates as they are available on this site."