WHERE OH WHERE IS MOBILE ANTENNA R&D????
Larry Coppala (KD4ZD)
on
June 22, 2000
View comments about this article!
Get "RICH QUICK"!
The first "Research & Development" department to produce a mobile antenna that meets these requirements
will!
- Works Bands 2M, 6M & 10M thru 80M
- Is no more than 5 feet tall
- No bigger around than 2 inches
- Automatic band changing
- Handle 150 watts
- Can be mounted on trunk lip
- Priced no more than $400.00
It's a crying shame after seven years of Icom 706's and the like, made to meet our needs with our smaller cars, that no one has produced a mobile antenna that is just as new & revolutionary.
I rest my case.
This article has expired. No more comments may be added.
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RE: Mobile Antenna R & D
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by KK9H on June 22, 2000
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If it is only 5 feet tall and up to 2 inches in diameter, what kind of efficiency could one expect on 80-10M? When the ad guys get going on this they can say what whatever they may, but they won't be rewriting the laws of physics.
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Mobile Antennas R&D
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by K4IA on June 22, 2000
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Heck if you want DC to daylight coverage that would be great! Why limit it to mobile antennas? - I want one for my home QTH.
Forget the laws of physics. I could turn it into a beam, stack-em, rack-em, phase-em and get Honor Roll in a month. Yeah dat's da ticket!
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Mobile Antenna R&D
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by N6TGK on June 22, 2000
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The ATAS-100 comes pretty darn close to those desired specifications and it seems to work "okay" but you just can't have an antenna that size without sacraficing performance.
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Mobile Antenna R&D
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by K5NIC on June 22, 2000
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Well, you don't get 2 and 6 m, but that is why they have a separate antenna jack for 2m/70cm. There is a screwdriver antenna for $150 bucks that will cover 10m - 80m continuous, and the seller says he has tested it as high as 6m. Don't know about the 6m claim, but a homebrew version adorns a relative's vehicle and works with 1.2 or less swr from 80 - 10 m.
At $150, it is half the price for other variations.
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MOBILE ANTENNA R&D
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by N2MR on June 23, 2000
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I put a 20mtr valor whip ($20) on the roof of my 88 Celebrity wagon in the beggining of February, cut some Alum. welding rod pieces to move it to 18,21,24mhz by standing on the roof of the car and changing bands. I've worked 98 countries as of 6/23 with a used ts-50 on both ssb & cw with the bulk of the countries on 20m & cw (God knew what he was doing when he set up the earth and 14mhz... this band rocks!). Now I'll admit that changing bands is not convenient, and does draw curious looks from people when you climb on the roof of your car (I don't mind dents, it's an 88 but I'm not 14 months pregnant either.) but mobile operation sure is more fun than I ever dreamed, even if I yank out the radio in 3yrs when ol sol goes back to sleep!
Synopsis... you don't need a stinkin $300 antenna and 10 bands to work mobile DX. If you are cheap and ingenious,
don't fear mobile cw, and keep your ears open on your way to work (early weekday mornings) on 20m you can save money and have fun!
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RE: Mobile Antenna R&D
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by VK2JNA on June 23, 2000
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(All said with a healthy amount `tounge-in-cheek'. No malice)
I've just developed it in the lab out the back! It looks a lot like a non-inductive 50ohm resistor with an so-239 connection for just USD400. Available with N connectors for a token fee more. Fantastic SWR as well (& that wasn't even on the requirments list, was it?)
Oh, did you want it to radiate ?? :-)
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Antenna R&D
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by W0FMS on June 23, 2000
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Antennas need to be a certain size (with resepct to the wavelength of the signal) to work effectively.
This is and has been around 50% of the size of a full wavelength antenna.
Even though there are advances due to computer modeling, this "physical limitation" applies to most, if not all,
designs. "Fractal" antennas show promise, but often are criticized, "Counterwound Toriodal Helical Arrays" do not work.. the Traffie "Hexagon" shaped antenna actually seems to work for a short antenna, but is still way to big
to be mobile.
Probably the best antenna for 80M - 6M (this includes "practicality" constraints-- the "bugcatcher" is more efficient
but much less convienient) is the Screwdriver antenna (DK3, High Sierra, ATAS-100 and others).
I don't want to discuorage reasearch and experimentation in physcially short antennas-- in fact this is a great
area for ham experimentation. But don't expect a miracle like this article states...
Fred W0FMS
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Antennas...
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by KK7GP on June 23, 2000
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I suppose you could make a 1/32 wavelength whip using you car body as the radiating elements!
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reply to mobile antenna issue
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by VE7CRA on June 24, 2000
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It seems that radio amateurs are not immune to the "smaller, cheaper, better, do everything" syndrome that pervades our society.
While the design & implementation of exceptionally capable radio transceivers has been made possible by ASICS, LSI, & other computer "spin-offs" the ultimate miniaturisation of these devices is limited only by ergonomic considerations. The same cannot be said regarding antennas. Owing to the fact that the physics of electromagnetics imposes certain minima upon radio antennas( ie: a portion of the wave front has to induce a current in a receiving antenna, & by reciprocity, there must be enough transmitter antenna to "launch" the transmitted wave) unless in the near future , an alternative set of physical laws are discovered that redefine electromagnetics, we will be stuck with variations of existing designs for some time.
It is characteristic of our 21st century society to hold the expectation that science will solve all our problems with yet another "miracle" breakthrough.
While I would never discount the possibility of alternative antenna systems, it would seem that there is a an formidable series of problems that conventional solutions would seem to exacerbate. For instance: Suppose that say, a sphere several inches in diameter could be made to radiate efficiently on 75 metres. I picked a sphere empirically, so substitute such geometric figures as you will, the fact remains that an intense local field would exist in the area of the radiator. Now, if we postulate that only a minimal field or no field exists, how does one communicate by electromagnetic waves where there is no field? I could go on, but you get the picture I am certain.
I would suggest that a radical departure from conventional methodology must take place in order to satisfy the demand for physically small antennas. As food for thought, let me tender an idea or two for consideration.
Suppose that we looked at "injecting" the signal into the "ether" via a probe of some kind. A capacitive probe offers certain advantages .....think about it, & you will see what I mean. I seem to remember the coupling impedance of "free space" being measured or calculated as 366 ohms. Surely it might prove interesting to attempt the construction of a wideband or frequency independent "coupler", to which one would merely feed RF at any frequency, & the coupler would transfer energy to the "ether" being a universal size, frequency not withstanding!
There certainly exists a wide-open field of experimentation in this arena, prime for amateurs who are not well enough informed to know that what they hope to achieve has been declared a "technical impossibility" by the scientific cognoscenti. For those of you who have had the patience to read my little offering, Thank You....for those who quit after a few lines, a small remittance for my printed soporific would not be untoward.
73, de VE7CRA, Brian
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DO IT
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Anonymous post on June 25, 2000
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Some one will now come up with the exact antenna this guy wants and get rich. Then this guy will be crying
"HE/SHE STOLE MY IDEA"!!!!!
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reply to "anonymous"
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by VE7CRA on June 26, 2000
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Anonymous: Nothing would please me more than to see a breakthrough in antenna design that would permit the type of antenna the original poster lamented the absence of. I did not offer any "ideas" as such, I merely offered a couple of avenues of thought for consideration.....so no-one can "steal" my ideas.
Intellectual property laws being what they are, if a concept isn't "copyrighted" a person would have little room for legal recourse. On the other hand, I have never claimed that anyone has "stolen" anything from me, nor am I about to start. I do, however, sign my name to to letters, posts, or public or private communications , in order to demonstrate that I am unafraid to stand by what I say, right or wrong. I do not understand the necessity of wrapping one's self in the cloak of anonymity.......to each is own, I suppose.
Brian Hind, VE7CRA
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Mobile Antenna R&D
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by AB0KP on June 27, 2000
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I don't think you will find something that works well on 80m will also work well on 6 & 2M. I solved the problem reasonably well with two antennas - a High Sierra Screwdriver (longer than 5ft!) antenna for 80-6m (does not work very well on 6m) along with a thru the glass 2m antenna. As far as I know all of the Transcievers that offer this range of frequencies also have at least two antenna jacks (one of which is dedicated to vhf) so in a sense the radio manufacturers have put two radio in one box.
On the other hand if you build one that works well, I would probably buy one! 73!
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RE: Mobile Antenna R&D
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by N6DUR on June 28, 2000
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A simple 3 legged Mag-Mount, with the mag-mount frame well grounded to the car body, $24 Ham Sticks with quick disconnects installed, tuned for the bands you like, mounted as high on the car as your XYL will allow, work great for 40 through 2M. If you can still find 6 feet Mobile Mark Heliwhips (The 10M is 3 Ft.), they work equally well, are a foot shorter than the Hamstick, have no stinger, but are tuned to the freq range of choice by carefully removing wire from the tip under the plastic cap. I use both antennas with the 706 Mk II and sucessfully enjoyed 2 cross-country mobile experiences, working all over the world on 40-10M. My current Mag-Mount is located on top of a 98 Ford Expedition and I have a Mag-Mount on top of a Mitsubishi Montero. Try it; you'll like it!! 73's Bob Wagner
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WHERE OH WHERE IS MOBILE ANTENNA R&D?
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by KD4ZD on June 28, 2000
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WHILE I APPRECIATE EVERYONE'S COMMENTS, I'M AMAZED HOW MANY OF YOU DIDN'T CAREFULLY READ WHAT I WROTE. A LITTLE CLARIFICATION, I'VE BEEN IN ELECTRONICS 48 YEARS. I'VE TRIED ALL THE MBL ANT SYS AND THEY DON'T MEASURE UP TO THE NEWER RIGS. "SMALLER & BETTER" IS RIGHT ON THE MONEY. WHY NOT? REMEMBER WHERE THE GASFET CAME FROM? THE MICROCHIP? THERE IS A GUY WITH WORKING PROTOTYPES OF MICRO ANTENNAS FOR VHF/UHF ALREADY. DON'T LET YOURSELF BE HEMMED IN BY OLD RULES. BE BOLD, EXPIERIMENT!
TO THE COMMENT ABOUT "SOMEONE STOLE MY IDEA". MY GOAL IN LIFE WAS TO BE HAPPY, NOT ATTAINING RICHES. AND I'VE BEEN BLESSED OVER & OVER WITH HAPPINESS. MONEY IS NOT MY DRIVING FORCE. MONEY WON'T BUY A LOVING WIFE, HEALTHY CHILDREN & GRAND CHILDREN!
73'S
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RE: Where is mobile antenna R&D???
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by KU4ET on June 29, 2000
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It's in the hands and minds of the hobbiest. :)
73's Owen KU4ET
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Mobile Antennas
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by WA4CNG on July 28, 2000
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Presently running FT-100 with AL-500 and Ham-Sticks (75-40-20-10-6) with quick disconnects. I am presently designing a single antenna whip with remotely switched coil taps for 75-10. Ham-Sticks are mounted on a tri-mag mount on roof of Explorer. Single band is good, but rapid change is sometimes painful. I really want my old green Webster Bandspanner back, but I burned it up on 15 CW in 1966......
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RE: Mobile Antennas
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by K3FT on August 22, 2000
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Greetings!
I have tried Hustlers, Outbackers, Hamsticks and the like. Mine work fine and I make QSO's all over the place on 75 -10M. (Nothin' like doing 20 WPM while driving 70 MPH on the open clear road! HI) However, I recognize the limitations of the service within which I am operating. I don't expect to be a big gun or a mini gun. But I DO expect to be able to operate and be heard.
No mobile antenna will radiate EFFICIENTLY on 75M due to the low radiation resistance and losses inherent in the mobile antenna environment. One must consider the laws of physics always. They haven't yet figured out how to break those and succeed.. but I suppose someone is trying to, every day! HI
However, it CAN and DOES radiate EFFECTIVELY (you can still be 'inefficient' and maintain 'effectiveness') when you take the time to install it properly and take into account the fact that the radiating portion must be as high and in the clear as you can make it. If you can enlarge the radiating element diameter and reduce the losses to a minimum it will work acceptably AS LONG as you are willing to accept the inherent limitations of you installation.
Clean connnections (you'd be amazed at how many skunky mobile antenna performance is due to cruddy connex, not bad antennas! HI). Tight connections, proper installation of radiating element and base mount. Proper matching between the rig output impedance the mobile antenna input impedance. Proper grounding to reduce DC and RF losses.
just my 25 cents worth (inflation!)
73
Chuck K3FT
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RE: Mobile Antennas
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by KD6OD on November 15, 2000
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Hi Chuck, I just couldn't resist responding to the comment that you made previously about no antenna can radiate efficiently on 75 meters.......I beg to differ with you sir, try a Swan 45 mounted top dead center on the roof, and shunt feed the base with a 500 pf capacitor. A couple of years ago I was driving about 100 miles north of LA talking to a friend of mine named Dave (KJ7AN) who lives in Dallas, Oregon and he thought that I was at home talking to him on my 124' inverted V at 43'; I was in fact using the above described setup, and in fact I was up in Oregon on vacation about 5 weeks ago, and when I was still about 300 miles south of his station on the Oregon coast he accused me of running a mobile kilowatt.................not to bore you, but one more example; on the same trip I was about 15 miles south of Coos Bay, Oregon where Clair (N7PXJ) lives, and he told me that I was the first and only station to peg his receiver at 60db over S-9.......and the rig I did all 3 of those transmissions on was an original IC-706 putting out about 100 watts. The match on 75 meters for me is 1.5 to 1, on 40 meters it drops to 1.2 to 1, measurements courtesy of my Bird 43.........the reason I mentioned that is that I never bothered to add any more capacitance, but I'm sure that I probably could have gotten it down to 1.05 to 1, but who cares? I just happened to have a 15KV LPN type in the junk box, and I tried it and it worked......I imagine that to get a flat match it might take closer to 700 or 800 pf, but if I had gone that route I would have to switch it out to work 40, because the match there would have been excessively high.
73's
Ron KD6OD
kd6od@netscape.net or
kd6od@yahoo.com
73's
Ron KD6OD
kd6od@netscape.net
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RE: Mobile Antenna R&D
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by KI8JT on December 18, 2000
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I see in the ads for the ATAS-100 that it does support 6, 2, and .75 as well as HF down to 40. Based on experiance is this not correct?
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RE: Mobile Antenna R&D
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by AD6LR on January 2, 2001
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Hello KD4ZD,
I would be very interested in learning more about
the antenna researcher you mentioned in your last
post. The section of the post I am referring to
is listed below.
"THERE IS A GUY WITH WORKING PROTOTYPES OF MICRO ANTENNAS FOR VHF/UHF ALREADY."
AD6LR
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WHERE OH WHERE IS MOBILE ANTENNA R&D????
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by N7HQK on January 15, 2001
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OK, how'bout this for a radical departure...
A truly active antenna that tunes itself dynamically can be implemented with a medium power IR laser mounted to fire in a vertical mode. The power of the laser is dynamically controlled to determine the height of a column of ionized air (Plasma) that is created above the laser thus the resonant frequency of the plasma antenna. Coupling to the plasma column is accomplished via a shunt feed that is created by a second IR Laser of lower power and servo mounted so as to intersect the first Lasers plasma column at a variable height.
Resonance and impedance is controlled via a MPU system and is adjusted on a very rapid, dynamic basis to correct for variations in the air density, vehicle speed, precipitation etc.
In implementation the un-deployed height is only a few inches and when deployed it would be a heigh as necessary to achieve resonance.
A few bugs to be worked out would be of course the safety issues... Tree trimming potential etc...
Food for thought! Mobile 23 cm to 160m!
BTW don't laugh, a "Star-trek Phasor" weapon has already been demoed based on this same technology. It uses two IR lasers to provide twin plasma paths to the "target" then ships a high voltage discharge down the "conductors" Tazer style...
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WHERE OH WHERE IS MOBILE ANTENNA R&D????
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by HA5CMG on May 25, 2001
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If you are looking innovations in HF Mobile antennas then you need to visit my website:www.hiqantennas.com
Read technical details, comparisons, Radiation Efficiency, then you may realize that in the past 50 years nothing came close to this PATENTED Hf Mobile antennas design.
It may not meet you height limit, however it performs well and it is making me RICH!!!
73 Charlie
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WHERE OH WHERE IS MOBILE ANTENNA R&D????
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by KB3BMT on May 30, 2002
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Anyne had any experience with the Spider 5 band mobile or the Pro Am five bander. interesting concept, but does it work? I can't find a Pro Am home page, so I haven't been able to get specs on it. Spider is at www.spiderantenna.com.
73
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RE: Mobile Antennas
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by W8JI on July 8, 2003
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>>>>RE: Mobile Antennas Reply
by KD6OD on November 15, 2000 Mail this to a friend!
Hi Chuck, I just couldn't resist responding to the comment that you made previously about no antenna can radiate efficiently on 75 meters.......I beg to differ with you sir, try a Swan 45 mounted top dead center on the roof, and shunt feed the base with a 500 pf capacitor. A couple of years ago I was driving about 100 miles north of LA talking to a friend of mine named Dave (KJ7AN) who lives in Dallas, Oregon and he thought that I was at home talking to him on my 124' inverted V at 43';
I'm sorry, but truthfully you have no idea what the efficiency of that antenna was. I regulary work Europe with my mobile on 75 meters, and the antenna is only 5% efficient. On 160 meters, I can beat many home antennas and my antenna is well under 1% efficient.
I could be puffing up my chest and saying my antenna is "super", but I know it isn't. It's more a matter of how much POORER the antennas I beat are.
It is a good mobile antenna, ten feet tall with a six foot hat at the very top and a large very good loading coil, but PHYSICS limits efficiency to a few percent on 80 meters. It will beat crummy antennas and even modest antennas IF I have the better path to DX, it is better than a clothes-line dipole, but it isn't magic.
Comparing an unknown antenna to another unknown antenna, on a different day and time and over a different path, isn't really a comparison at all.
73 Tom
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RE: Mobile Antennas
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by AA4PB on July 8, 2003
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Be careful how you spec things. I have a dummy load that meets all your requirements perfectly because you didn't specify anything about the efficiency of the antenna. Some things will never change and one of them is that the ability of the mobile antenna to radiate signal is based primarily on its physical size. You can make various trade-offs differently but you will never find the perfect mobile antenna for every environment.
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RE: Mobile Antennas
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by N0TONE on October 10, 2003
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As others have said, you left out the specification for efficiency. So any sort of dummy load could meet your specs.
To make an antenna shorter, you have to do something to reduce the resultant resonant frequency. For mechanical reasons a center loading coil is most common, although top loading leads to a more efficient antenna. To make the center loading coil more efficient, you should be using a large diameter coil made of 1/16" to 3/16" tubing, not skinny little 12 gauge wire. Do you see the problem? To make an antenna short, but not sacrifice efficiency, you have to make it fatter.
Congratulations to HiQ antennas. They have at least realized that efficiency is key. The website is pretty inadequate, though, and shows that while they know the right thing to focus on, they don't know how to specify it. Specifically, efficiency WILL vary with band you're on. They spec efficiency, but don't indicate what frequency it's on. They also don't indicate how they measured it. Based on the test equipment in their modestly-equipped lab, they probably measured the coil, then used simulation software to predict efficiency, which is a poor approach. However, better than others. There's a fairly predictable approach using the resonant base-feed resistance that takes into account all the antenna losses. The coil is only one part. On lowbands (80 meters), a stainless steel lower section contributes as much loss as a good coil. The base impedances which are advertised on the website do not correspond with the claimed efficiency.
Also, the base impedance spec of their antennas is given - but only at one frequency. In order to ensure that the rig/tuner you use will work with the antenna, you need to know impedance at many frequencies.
Finally, in the comparison of antennas, it's all words. Show us pictures. If it's built better, a picture proves your point. Until then, it's just marketing mumbo-jumbo. Anybody can claim anything.
As far as becoming rich, here's how it looks to me:
Income: $400 per antenna, sell 1000 per year, that's about $400,000 per year. Materials and labor to build one antenna: $300 (assuming $8 per hour manual labor). A decent ad campaign in QST, CQ, 73, etc, $30K. That leaves a net profit of $80K. Not a bad income, but below average in some cities. Definitely not wealth-building levels.
AM
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WHERE OH WHERE IS MOBILE ANTENNA R&D????
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by N0RTU on March 28, 2004
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WHERE, OH WHERE, IS THE MOBILE ANTENNA R&D?????
The answer to your post lies simply in two places Larry!
1. In your local library, here on the internet, and in magazines you may have on the subject of Mobile hf antennas.
2. As a Ham, YOU ARE THE R&D GUY!
Read, understand, experiment!
Ham radio SHOULD BE as much learning as operating.
The answers are not in your checkbook!
Try the local library!
My $.02
73
Mike
N0RTU
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RE: WHERE OH WHERE IS MOBILE ANTENNA R&D????
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by WA6BFH on April 17, 2005
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The Hustler antenna fits the bill almost exactly as you outline it. I have used mine for many many years on 6 through 80 Meters. With minimal modification, I have in the last several years also used it on 2 Meters, as well as 135 and 70 centimeters.
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