View Full Version : I CAN"T BELIEVE IT WORKS
KA4DPO
11-15-2006, 05:25 PM
I got this cantenna thingy at a hamfest and hooked my rig up to it. I'm not making this up now, when I keyed down on the mike it loaded up 1:1 on 11 meters.
I got to thinking, I wonder what else it will tune.
It tunes up 1:1 on every band, it's like magic. Tomorrow I'm going to try and make some contacts on 160 with it. Boy oh boy I can't wait.....
nm5tf
11-15-2006, 05:36 PM
trolling...trolling...trolling....
keep those doggies trolling....
RAWHIDE!!!!!!!!!!!!!!!!
http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
VE7NOT
11-15-2006, 05:44 PM
Quote[/b] (KA4DPO @ Nov. 15 2006,09:25)]I got this cantenna thingy at a hamfest and hooked my rig up to it. I'm not making this up now, when I keyed down on the mike it loaded up 1:1 on 11 meters.
I got to thinking, I wonder what else it will tune.
It tunes up 1:1 on every band, it's like magic. Tomorrow I'm going to try and make some contacts on 160 with it. Boy oh boy I can't wait.....
Sure kill the experimenter http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Quote[/b] (KA4DPO @ Nov. 15 2006,12:25)]I got this cantenna thingy at a hamfest and hooked my rig up to it. I'm not making this up now, when I keyed down on the mike it loaded up 1:1 on 11 meters.
I got to thinking, I wonder what else it will tune.
It tunes up 1:1 on every band, it's like magic. Tomorrow I'm going to try and make some contacts on 160 with it. Boy oh boy I can't wait.....
There's nothing like those old Heathkits. Let me know when you get BY1. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
cu2jt
11-15-2006, 06:16 PM
Big deal. I have a 33ft vertical on the roof. I tune it on 80 thru 6 meters with a MFJ-962D antenna tuner. OK, on 80m it has about 5 KHz bandwidth but in the last WAE RTTY contest I worked VE, W, 7X2 and a dozen other very valuable multipliers. On 6m, I have worked FG, FM, KP4, W, VE with 100 watts.
It should'nt work but for some odd reason, it does...
Roof schmoof. My Cantenna is in the basement. Doesn't get out that well with QRP. ;)
73, JP, K8AG
The Barker & Williamson BWD90 is a dummy load with wires that will allow you to make contacts. It is not a great antenna and I do not recommend it, but is sure is broad. (1.8-30MHz)
73,
Terry, K7FE
wa4ilh
11-15-2006, 07:13 PM
Quote[/b] (K8AG @ Nov. 15 2006,11:20)]Roof schmoof. My Cantenna is in the basement. Doesn't get out that well with QRP. ;)
73, JP, K8AG
With enough funding, I could develope one that has more than 10 db gain over yours...... http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Tom WA4ILH
Quote[/b] (K7FE @ Nov. 15 2006,11:37)]The Barker & Williamson BWD90 is a dummy load with wires that will allow you to make contacts. It is not a great antenna and I do not recommend it, but is sure is broad. (1.8-30MHz)
73,
Terry, K7FE
Terry, some folks say the new Comet vertical is the same thing. Leaky dummy load.
W4HAY
11-15-2006, 07:30 PM
Quote[/b] (cu2jt @ Nov. 15 2006,18:16)]It should'nt work but for some odd reason, it does...
Why not? Any wire will radiate.
Consider the classic dipole fed with ladder-line. The SWR is horrendous, but the ladder-line minimizes losses while the transmatch converts the (very) complex impedance into something the transmitter can work with.
KA4DPO
11-15-2006, 07:55 PM
Realy? That's so cool....... http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
KA4DPO
11-15-2006, 07:56 PM
So if I soak some shoelaces in salt water can I load them up with ladder line?
wb7dmx
11-15-2006, 08:03 PM
yep, but only if your wearing them.
KA4DPO
11-15-2006, 08:03 PM
Wait, wait, HAY, #then if I plotted S11 and S22 on a Smith Chart, and found the conjugate for each reactance circle #could I replicate the required L C constants to cancel the reactances using a transmission line transformer leaving me only with the resistance component or are my shoelaces all wet?
wb7dmx
11-15-2006, 08:05 PM
Quote[/b] (KA4DPO @ Nov. 15 2006,13:03)]Wait, wait, HAY, #then if I plotted S11 and S22 on a Smith Chart, and found the conjugate for each reactance circle #could I replicate the required L C constants to cancel the reactances using a transmission line transformer leaving me only with the resistance component or are my shoelaces all wet?
it will work much better if you and the shoelaces are all wet and your standing in salt water.
n0nwo
11-15-2006, 08:07 PM
Quote[/b] ]Wait, wait, HAY, #then if I plotted S11 and S22 on a Smith Chart, and found the conjugate for each reactance circle #could I replicate the required L C constants to cancel the reactances using a transmission line transformer leaving me only with the resistance component or or my shoelaces all wet?
Yes that will work, but you will need a nine foot long wet noodle used as a matching sstub. #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif #
You just can't go wrong with one of those cantenna thingys.
Minton
ve2nsm
11-15-2006, 08:44 PM
Well, I have a 1000' roll of RG58 here, and with nothing connected at its end it's so good that the higher in frequency I go, the lower the SWR !!! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
About 20 years ago I was using my new Cantenna to adjust my transmitter on ten meters and a friend a mile away came on the freq and asked who was sending a carrier, I switched to fone and called him back. He wanted to know why I was so weak, since we were only a mile apart...I explained about the cantenna, but he had a Horizontal Yagi antenna hooked up and there was a polarization mismatch since my cantenna was vertical
wb7dmx
11-15-2006, 09:46 PM
Quote[/b] (k8jd @ Nov. 15 2006,13:47)]About 20 years ago I was using my new Cantenna to adjust my transmitter on ten meters and a friend a mile away came on the freq and asked who was sending a carrier, I switched to fone and called him back. He wanted to know why I was so weak, since we were only a mile apart...I explained about the cantenna, but he had a Horizontal Yagi antenna hooked up and there was a polarization mismatch since my cantenna was vertical
yes, that is very true, the resistor inside the cantenna is in a vertical position, but because of the reflector being a circular shape, that would make the pattern more circular.
k4kyv
11-15-2006, 10:29 PM
Give this wonder a try. It consists of some power resistors in a metal box with an SO-239 connector and one or two feedthrough insulators, depending on whether you want a balanced or unbalanced antenna. To add weight and take up space inside the box, some scrap PC boards are added and the whole thing is potted with epoxy.
These things have been around for decades. The ARRL Laboratory bought one, X-rayed it, opened it up to have a better look, and photographed the insides, which were shown in QST in an equipment review article in the Nov 1984 issue: Maxcom; Antenna Matcher And Dipole Cable Kit
Now they are New and Improved - With an Expanded Tuning Range - To 1.3 GHz!
http://www.maxx-com.com/OurModels.html
Pricing Info (http://www.maxx-com.com/InternetSpecialPricing.html)
wb7dmx
11-15-2006, 10:44 PM
I seen them in the early seventies, my brother-in law actually bought one just to tear it apart to see what was inside, it was just a piece of carbon resistor with a eye bolt on each side to connect you dipole ends, but it did show a perfect match on all bands because the resistor was connected across the coax fitting, and it did work because the dipole was connected to the coax fitting also.
kc7mrq
11-15-2006, 10:52 PM
Quote[/b] ]Now they are New and Improved - With an Expanded Tuning Range - To 1.3 GHz!
According to their testimonial page, they can also double as a bikini top. What a wonderful product.
WA2ZDY
11-15-2006, 11:13 PM
I was just going to suggest a maxcomm for the shoe laces when I saw Don's post. Maxcomm, B&W . . . great stuff. They've made their makers plenty of cash!
Someone had a post in the wanted ad last week looking for a maxcomm. It was all I had to not answer the guy. I decided he knew what he wanted.
wa4brl
11-16-2006, 05:02 AM
edit to deleted comments
VE7NOT
11-16-2006, 05:05 AM
Quote[/b] (wa4brl @ Nov. 15 2006,21:02)]I wonder if Sim is feeding that thing with 500 feet of RG-174? Old waterlogged coax is just as bad. Just like a lossy load (the Cantenna or the BWD90), a lossy feedlind makes for broadband tuning. Looks good to the SWR bridge, but the efficiency is zilch.
RG 58 btw http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif And quite new.
Truthfuklly it could have water in the line after today
k4sav
11-16-2006, 05:23 AM
Quote[/b] (KA4DPO @ Nov. 14 2006,14:25)]It tunes up 1:1 on every band, it's like magic. Tomorrow I'm going to try and make some contacts on 160 with it. Boy oh boy I can't wait.....
I hear those cantenna thingies work better if you fill them with salt water.
VE7NOT
11-16-2006, 05:26 AM
They fear us..people always fear experimenters they dont understand! http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
wb7dmx
11-16-2006, 08:58 AM
I think we understand you quite well, its your theory behind your experiment that we don't understand.
we all know why it won't work, and you need to explain with the theory why it does work.
do you have any books on how antennas work?
you might get the ARRL antenna hand book and learn how to do modeling of antennas before you do the physical construction of one,
just a thought that might help you with your experimenting.
W4HAY
11-16-2006, 01:22 PM
Quote[/b] (KA4DPO @ Nov. 15 2006,20:03)]Wait, wait, HAY, #then if I plotted S11 and S22 on a Smith Chart, and found the conjugate for each reactance circle #could I replicate the required L C constants to cancel the reactances using a transmission line transformer leaving me only with the resistance component or are my shoelaces all wet?
Sure! They're called 'tuned feeders', but unfortunately only work at specific frequencies for a given antenna/feedline/transformer combination. Thus the variable L and C in the transmatch to make them work at many frequencies.
I use coax feeders, but only because the transmission line has to run a considerazble length indoors. If I had direct access the the great outdoors, I'd have a honkin' big-a** dipole fed with 600 Ohm ladderline and one of those classic parallel-line tuners you see in the old Handbooks.
Maybe if you put 3 cantennas in a line and feed the center one you can get about 7 db gain and a bit of front-to-back ratio. Sort of a cant-yagi. http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
nm5tf
11-16-2006, 02:22 PM
Quote[/b] (VE7NOT @ Nov. 15 2006,16:26)]They fear us..people always fear experimenters they dont understand! http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
very true Sim...look what happened to Nikola Tesla http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
W5HTW
11-16-2006, 02:58 PM
I have been working on a cantenna for years. One of the difficult areas has been rotation. I finally installed two prop pitch motors, one for horizontal rotation and one for vertical rotation. I mounted the cantenna in gimbal mounts, and have it sitting on the floor under the desk.
I have also installed a hose and feed system, as I have learned that different grades of oil give it different gain and directional characteristics. I can now, while it is rotating, change the oil, with a system of pumps, to achieve not only variable gain and direction, but different angles of radiation.
The oil is run though a HVAC system, so that the temperature can be adjusted precisely, which allows me to control the radiation resistance.
The next project is to mount the entire assembly a used barber's chair, so I can raise and lower it as I deem necesssary at any given moment. Or even several times per moment, to simulate Arctic flutter. Once I have perfected that, I will proceed with the plans for high speed rotation of the entire system, including the barber's chair, to give me all angles of gain, radiation, flutter and directivity simultaneously. Presently it operates on 240 VAC, but when I get to that stage, I will switch to 440 3-phase. With a 4CX15000 (see relevant thread) and 500 VDC bias supply, all mounted within the cantenna.
Ed
KA4DPO
11-16-2006, 06:59 PM
That's a great idea HTW, you could change the radiation angle by raising and lowering the chair. And with a 4CX15000 to provide moderate power you can ionize your own layer when band conditions get poor. Please sen me the plans, I have to build one.
I have a few questions. When I fire up the 4CX15000 do you think the loss on my RG-58 coax will attenuate the signal too much. I'm only looking for moderate output so the supply is limited to 7,500 V on the plate at 1 Amp.
If I use Oil of Olay in the can will it smooth the E-field?
Should I get fire insurance?
VE7NOT
11-16-2006, 07:33 PM
Quote[/b] (wb7dmx @ Nov. 16 2006,00:58)]I think we understand you quite well, its your theory behind your experiment that we don't understand.
we all know why it won't work, and you need to explain with the theory why it does work.
do you have any books on how antennas work?
you might get the ARRL antenna hand book and learn how to do modeling of antennas before you do the physical construction of one,
just a thought that might help you with your experimenting.
I have many books on how antennas work.
The next step is actually now to find out why it tunes all those bands. So far I haven't found it in the books.
wb7dmx
11-16-2006, 07:47 PM
I already forgot what we were talking about.
could you discribe in more detail what you have and the readings your getting ?
sounds like your loading up a dummy load on all bands to get the low swr readings, and your not using a tunner of any kind, so what are you using for the rf source and what are you taking the readings with ?
KA4DPO
11-16-2006, 08:32 PM
A dummy load? #You're a cretin aren't you.
I'm using a non reactive carbon element having a nominal resistance of 50 ohms. #It is encapsulated in a cylindrical metal vessel filled with a viscous liquid that absorbs heat from the carbon element which is generated by thermionic agitation by absorption of alternating electric current.
Dummy load indeed!
Experiments to date show that if the vessel is filled with mineral oil it produces a haaarrd radiation pattern.
If the vessel is filled with baby oil it produces a smoooth radiation pattern.
If the vessel is filled with cooking oil, you can make french fries. #MMMM..
#http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif
VE7NOT
11-17-2006, 12:48 AM
Quote[/b] (wb7dmx @ Nov. 16 2006,11:47)]I already forgot what we were talking about.
could you discribe in more detail what you have and the readings your getting ?
sounds like your loading up a dummy load on all bands to get the low swr readings, and your not using a tunner of any kind, so what are you using for the rf source and what are you taking the readings with ?
All reading are below 1.5
It was jury rigged together sort of just to test and so far has preformed well.
Yes the coax is cheap rg-58
The antenna as discribed are 2 96" whips joined together and feed at the center. The wire was supposed to go to the balcony railing from the braid but the match was better without.
Like I said it was an experiment.
And I quickly sketched it below on ms paint
http://i15.tinypic.com/44l9xja.jpg
N1XHF
11-17-2006, 12:50 AM
I love my mineral oil filled cantenna!
wb7dmx
11-17-2006, 01:35 AM
and what is the hf rig ?
Quote[/b] (wa6oml @ Nov. 16 2006,09:22)]Quote[/b] (VE7NOT @ Nov. 15 2006,16:26)]They fear us..people always fear experimenters they dont understand! http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
very true Sim...look what happened to Nikola Tesla http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
I'm just glad I'm on the other side of the Continent. When they start 'experimenting' with anti-matter, I'll have 3,000 miles and two mountain ranges between the chain reaction and the QTH. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
wd4brp
11-17-2006, 03:45 AM
That's nothing ! #I have a dummy load that loads up at 1:1 on all bands 160 to 10 meters. http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
Oh heck, I was going to re-invent the Maxcomm right in front of your eyes, guys, but you smart-alecks beat me to it !
I can remember when the League tore apart the Maxcomm unit. All of a sudden, the ad no longer appeared in the magazine, either!
However, I seem to remember the Army using some sort of "frequency agile" antenna that was basically a dipole with a big 50 ohm resistor stuck in the feedpoint. 1:1 SWR, all-right ! ! !
http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
73, and Good DX ! Jim
Dr. Frankenstein, is it true the villagers burned your castle because they didn't understand that you were simply experimenting with Amateur Radio?
VE7NOT
11-17-2006, 08:28 AM
Quote[/b] (wb7dmx @ Nov. 16 2006,17:35)]and what is the hf rig ?
TS 680 Kenwood. 160-6m
Quote[/b] ]there was a polarization mismatch since my cantenna was vertical
Just tip it over on it's side for horizontal polarization!!!
It will be ok...really!...no really, just try it!!
KA4DPO
11-17-2006, 04:27 PM
Quote[/b] (k7mh @ Nov. 17 2006,01:49)]Quote[/b] ]there was a polarization mismatch since my cantenna was vertical
Just tip it over on it's side for horizontal polarization!!!
It will be ok...really!...no really, just try it!!
Yeah but at least wait till the fries are done..
wa4ilh
11-17-2006, 04:37 PM
Quote[/b] (N1XHF @ Nov. 16 2006,17:50)]I love my mineral oil filled cantenna!
I tried WD-40 but now it only works on the 7 Mhz band. I'm trying to locate some WD-20.... http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Tom WA4ILH
KM5FL
11-17-2006, 04:46 PM
Quote[/b] (wa4ilh @ Nov. 17 2006,11:37)]Quote[/b] (N1XHF @ Nov. 16 2006,17:50)]I love my mineral oil filled cantenna!
I tried WD-40 but now it only works on the 7 Mhz band. #I'm trying to locate some WD-20.... http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Tom WA4ILH
Havoline 10 W 40 works pretty well... I'm experimenting with some generic 140 W gear oil for 160 meters.. I'm getting some iffy results in the summer but when winter rolls around, the cantenna radiation really slows down..
KM5FL
wa4ilh
11-17-2006, 05:02 PM
Quote[/b] (KM5FL @ Nov. 17 2006,09:46)].... I'm experimenting with some generic 140 W gear oil for 160 meters.. I'm getting some iffy results in the summer but when winter rolls around, the cantenna radiation really slows down..
KM5FL
LOL... You forgot to compute the viscosity factor of your feed line. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
Tom WA4ILH
KA4DPO
11-17-2006, 09:13 PM
Try some antenna grease on that sticky cantenna, be sure to warm it up before you try 160 though.
n2cfj
11-17-2006, 09:44 PM
About 20 years ago one of the magazines, (QST, CQ 73?), had an article about an experiment loading a wet clothesline. they actually took the time to compare types of rope. It just occurred to me, (its late in the day and the coffee pot is empty) that some clothesline is wire with a plastic covering. If it was set up with pullies as you would between two apartment buildings, you could adjust the feed point to tune on various bands.
W5HTW
11-18-2006, 02:54 AM
Quote[/b] (k7mh @ Nov. 17 2006,01:49)]Quote[/b] ]there was a polarization mismatch since my cantenna was vertical
Just tip it over on it's side for horizontal polarization!!!
It will be ok...really!...no really, just try it!!
GOSH NO! Won't the Scotch run out? At 22 bucks a fifth, I don't want even a fourth of it to flow out. Besides, it helps me rotate, even when the cantenna isn't.
Ed
W5HTW
11-18-2006, 02:55 AM
Quote[/b] (n2cfj @ Nov. 17 2006,14:44)]About 20 years ago one of the magazines, (QST, CQ 73?), had an article about an experiment loading a wet clothesline. they actually took the time to compare types of rope. It just occurred to me, (its late in the day and the coffee pot is empty) that some clothesline is wire with a plastic covering. If it was set up with pullies as you would between two apartment buildings, you could adjust the feed point to tune on various bands.
Lots'a dem dose t'ings in Brooklyn
They ain't ain't even filled with earl.
Ed
KM5FL
11-18-2006, 03:30 AM
Quote[/b] (wa4ilh @ Nov. 17 2006,12:02)]Quote[/b] (KM5FL @ Nov. 17 2006,09:46)].... I'm experimenting with some generic 140 W gear oil for 160 meters.. I'm getting some iffy results in the summer but when winter rolls around, the cantenna radiation really slows down..
KM5FL
LOL... You forgot to compute the viscosity factor of your feed line. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
Tom WA4ILH
Hey, I never thought of that. Can you help me find the formula for calculating the viscosity factor??
80 w gear oil works great on 80 meters. When winter slows down the radiation, I just spray on 2 coats of black radiator paint. http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
KM5FL
KA4DPO
11-18-2006, 04:50 PM
Quote[/b] (KM5FL @ Nov. 17 2006,20:30)]Quote[/b] (wa4ilh @ Nov. 17 2006,12:02)]Quote[/b] (KM5FL @ Nov. 17 2006,09:46)].... I'm experimenting with some generic 140 W gear oil for 160 meters.. I'm getting some iffy results in the summer but when winter rolls around, the cantenna radiation really slows down..
KM5FL
LOL... You forgot to compute the viscosity factor of your feed line. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif
Tom WA4ILH
Hey, I never thought of that. Can you help me find the formula for calculating the viscosity factor??
80 w gear oil works great on 80 meters. When winter slows down the radiation, I just spray on 2 coats of black radiator paint. http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif
KM5FL
I wonder what Marvel Mystery Oil would do?http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif
http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif
w7lpn
11-18-2006, 07:05 PM
Quote[/b] (VE7NOT @ Nov. 15 2006,10:44)]Quote[/b] (KA4DPO @ Nov. 15 2006,09:25)]I got this cantenna thingy at a hamfest and hooked my rig up to it. #I'm not making this up now, when I keyed down on the mike it loaded up 1:1 on 11 meters.
I got to thinking, I wonder what else it will tune.
It tunes up 1:1 on every band, it's like magic. #Tomorrow I'm going to try and make some contacts on 160 with it. #Boy oh boy I can't wait.....
Sure kill the experimenter #http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif #http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
NOOOOO! You'll never stop me from wasting my $$ and being stubborn and refusing to just buy it already made!
I love to tinker...it's the best part about this hobby. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif