gizmotchy vs. maco

[Master Chief]

Re: Gizmotchy/ maco

You all want to take a 19 db rating to task, but nowhere on here has anyone refuted or even argued against the CB Magazine review.

Its good to see that you are finally getting to the root of it. The "review" from CB Magazine I linked to earlier, which you failed to affirm that it is the "review" you've been going on about, is anything but a technical review, as I stated earlier. So it appears someone DID argue against it.

I've also run several antennas in my time, and I prefer my Gizmo. I make no bones about it, and I'll never say they are the only antennas to choose from. I'm not noticing the same attitude from most of you though.

You are not paying attention. Nobody cares that you choose one antenna over the other. The issue at hand is the 19db claim. I don't think anyone has really given their opinion on one antenna over another.

I truly do try to make informed and knowledgable statements about things I know, and I am still sticking to my assessment. HANDS DOWN, FOR ME IS THE "GIZMOTCHY" v/s the maco.

Great! good luck with that (except for the 19db thing).

That was my answer and I'm sticking to it!!! I do have the right to my opinion!!

You sure do! Nobody said you didn't. But, if you stick to your foolish assessments (the 19db thing), people might think you a.....

 

[freecell]

i could end all of this with any one of a number of basic first year math problems. my point would be that some people spend years screwing with antenna systems and don't even have a working knowledge or simple understanding of the fundamentals.

just for example, if an antenna exhibits a multiplier factor of 2 when energized with any given amount of power, show the math used to convert the multiplier factor into a gain figure. sure a lot of us already know the answer but how many of us know how it is derived and consequently solved?

or refer back to the isotropic gain chart i posted previously and work any of the four formulas and solve the equation when given 1 watt of transmitter power inside a sphere with a radius of 1 meter as the variables and find the amount of power distributed per square meter inside the sphere. let's see what you've learned in 30 years.

if any of you actually think yourselves to be engineering level material just dive in and provide the answers. i'll be waiting.

if you're as sharp as you claim to be then you can do this stuff in your head. by all means feel free to use writing instruments, paper and calculators. don't forget to invite all of your genius buddies too.

 

[Master Chief]

It COULD have 19 dB gain. Problem is, nobody is specifying "dB gain over WHAT".

I hinted towards that at the very beginning. Still, the majority of us all agree on the much accepted "dbi/dbd" rating.

There will be no acceptance of empty "db" claims on THIS forum!

There is one manufacturer of antennas used for CB who makes honest claims.

HONEST ANTENNA CLAIMS
(I'll probably get some heat for this one!)

 

[freecell]

i can tell you this, no one who believes the ridiculous claims made by charles with reference to the gain of his "giz" will be solving either of the problems i presented above. i'll deem anyone who can solve both of those problems as worthy of investing more of my time into explaining just exactly why the gizmotchy claims are bogus.

 

[freecell]

thanks MC....A1 Antennas? you'll get no heat from me.

i'm still waiting for someone to provide the answers/solutions to the problems i posited previously.

"just for example, if an antenna exhibits a multiplier factor of 2 when energized with any given amount of power, show the math used to convert the multiplier factor into a gain figure. sure a lot of us already know the answer but how many of us know how it is derived and consequently solved?"

"or refer back to the isotropic gain chart i posted previously and work any of the four formulas and solve the equation when given 1 watt of transmitter power inside a sphere with a radius of 1 meter as the variables and find the amount of power distributed per square meter (effective area) inside the sphere."

 

[davegrantsr]

roughly 3 db of gain gives (or in the case of an antenna, IMPLIES) doubling the power output. SO, 19 db IMPLIES doubling the output more then 6 times. so, a 1 watt XMTR would sound like:
1x2=2
2x2=4
4x2=8
8x2=16
16x2=32
32x2=64
key up 1 watt on a 5 element gyzmotchy at the same height, next to, etc, 64 watts on the reference dipole. the reference dipole just won that keydown. bigtime. back the power on the dipole down to 8 or 16 watts & we'd have a race. HOWEVER, since this discussion revolves around the short-boomed 5 element gyzmotchy, and NOT optimally tuned yagis (or quads) of other dimensions, i can state that there are ARE other directional 5 element antennas that WOULD outperform the gyzmotchy under the same conditions.
now, aiming 5 elements of ANYTHING at my neighbors house, running even a lowly 150 watts would cause me the same aggravation as keying 1 or 2 4cx15000a's on the reference dipole, so, to me, the point is moot. NOW, if i lived in some God-foresaken no mans land such as the empty fields of kansas, i'd have up 100' of tower & personally TRY every antenna i could get my hands on. while 13 elements of gyzmotchy(isn't that what's on their site?) would LOOK impressive, an old moonraker 6 or even a laser 400 would outperform it.
OK, let's get back to arguing about galaxies, & not rewrite science.

 

[bob85]

i am not scared of getting it way wrong as i do not believe you will show me unless i get it wrong, so heres some numbers,

area of shere with r=1mtr 12.56637 m2

1 .0795775 w/m2

2, .1591549 w/m2

3, .3183099 w/m2

4, 1458.973435 w/m2

 

[freecell]

davegrantsr....

sorry, wrong answer.

X-multiplier.....dbi.
factor

1..... 0
2..... 3.01
4..... 6.02
6..... 7.78
8..... 9.03
10.... 10.00
12.... 10.79
14.... 11.46
16.... 12.04
18.... 12.55
20.... 13.01
40.... 16.02
60.... 17.78
80.... 19.03........*the claimed gain for the giz.
100.... 20.00
18334.... 42.6

the conversion from multiplier to db is an exponentially graduated logarithm. the formula for converting the multiplier factor (X) into db gain is:

10log[10]X=()db.

bob85........A+

 

[bob85]

i dont even know how to type the p2 divide p1 10 log thingy in here lol

 

[freecell]

use windows scientific calculator........

Dec. Degrees

type 80....log....X10

 

[davegrantsr]

i oversimplified the #'s, freecell, for those of us like me who need more hands & feet then we have, to count our paychecks. the resulting #'s were used to show what the real world results would be. roughly. if bob got an A+, i think i deserved a B for effort . nobody else tried. or they were at work 8)

 

[freecell]

that's the difference between a linear progression and an exponential logarithm. i'll split the difference with you. your score is 80%.

here's a "real world" test comparison that can be used to debunk the gain claim.

given an antenna with a gain of 19.03 dbi. at a multiplier factor of 80X, calculate the Effective Radiated Power (Carrier and PEP) in the favored direction when excited with an FCC Type Accepted Citizens Band Radio Transmitter.

320W ERC, 1280W ERPEP

given the same antenna with a claimed gain as above but questionable as to the ability of the antenna to produce the stated gain, describe a simple test comparison procedure to establish as to whether or not the stated gain figure is true.

simple. erect a 1/4 wave ground plane at the same feedpoint height as the antenna in question and feed the ground plane with a transmitter capable of producing the figures provided as the correct answer to the previous question and feed the antenna in question with an FCC Type Accepted Citizens Band Transmitter.

if 10log[10]80=19.03
and if 4WC/16WPEP(80)=320WC/1280WPEP then

4WC/16WPEP(80)=320WC/1280WPEP(1), or

4WC/16WPEP into the 5el Gizmotchy=320WC/1280WPEP
into a Unity Gain 1/4 wave ground plane at the
same feedpoint height........wishful thinking not supported by the facts.
.

 

[marven]

Gismotchy v/s maco

I think I can rest my case!!

The manufactures stats were listed here, true.


However, the original question seems to have been ignored.
Testosterone or ego? I'm not sure why, and don't really care.


For any honest real world assessment of the difference, all we came up with were theoreticall meanderings. And the "let me quote something" without any real context or sources.

For anyone trying to answer the question of how these 2 antennas actually compare. I hope you came up with a few places to check on your own.


I was actually hoping for some real education, but the "I can be mathmatically inclined", seems to have taken over.
I also was a math major in college.
But the theories don't always work in the field. The antenna manufacturers don't use the same testing criteria. Now I've learned that everyone of them got it wrong, except for one guy!!

WOW!! So much for theory.

I'm sure that all of you will just ignore my next post here, if you don't outright delete it. However, I'm hoping some of you realise what I'm saying. As, pointed out by "freecell", customers do use these forums as well as people working in the industry.
My customers, and if your honest with yourselves, yours also, want your opinion. Not the math or other things, we have studied.
To just jump on the bandwagon, "of I know better and can use a calculator", doesn't begin to answer the question. Nor does it truly do justice to the subject. We have all read books, now is the time for "the rest of the story".

That's what I'm NOT seeing!!
The impulse to start treating everyone as ignorant or uneducated, if they don't agree with you has REALLY got to stop.

Just my .002 cents.
marven :roll:

 

[Peddler]

I thought someone said this dead horse was being whipped enough and locked the thread, correct?

 

[Switch Kit]

However, the original question seems to have been ignored.
Testosterone or ego? I'm not sure why, and don't really care.

Very good observation Marv , sometimes it seems like it can be so bright in here that it can have a blinding effect. :? Peace