IMAX 2000 INSTALL.

[AudioShockwav]

I would not go as far a calling the I max or the 99 junk, they do work.
There are a lot of guys running the I-max on 10/11/12/15/17( and 20 meters) with a tuner just because they are cheap and take up little room.
Depending on how you view the antenna I consider it a .64 at 11 meters.
For 10 meters it's a 5/8 antenna, for 15 it is a 1/2 wave antenna, 12 and 17 are close to the 10 and 15 meter band for that wideband coupling to work.
It is not bad for a c note to have a multi-band antenna that works that well.
The antenna rates a 4.5 out of 5 on 8 pages of reviews over on E-ham.
I have used the A99 in the past on 10/11/12 meters with a lot of success.
I fact I have won a few DX contests using that antenna.
Yes, the coil/cap matching network in the bottom of the antenna might not be optimum, but there are worse out there.
We all know that it was a huge lie to call it a 9.1 db gain antenna.
It still gets a signal on the air for a lot of guys.
I compared my I10K to the Antron 99 and the I10K did show a modest increase in signal strength, ( as I expected it to) but it is nothing to set the house on fire about....I do not think it is a lousy as a lot of guys make it out to be.

73
Jeff

 

[Justme]

Any 5/8 wave antenna doesn't have more as 2.7 dB gain over a 1/4 wave antenna.
It is actually 3 dB but any end fed antenna that is fed with coaxial cable needs an network to get the high impedance down to 50 Ohm.
And introduces losses, same goes for the Imax 2000....

That is real world antenna theory.
That gain comes from the lower angle of radiation, which prefers to be used for less hops to reach your counterpart, hence lower losses.
I saw many posts describing the network in the Imax 2000 as very lossy, even going as far as giving it 10 dB loss, poppycock...
If that were true, please explain why i can put 1 KW into that network and according those claims lose 900 watts into that network without burning it up?

A friend puts 2 KW in it on 17 - 10 and even then doesn't succeed to burn it up with the claimed 1800 watt losses.....

Truth is, it works fine, in the network there will be losses although limited to a few watts with 1 KW in it, but that is the same as in a standard alu tubing 5/8 wave antenna with it's network feeding it to 50 Ohm.

Lowering those few watt losses can be done with a bigger wire in the coil to lower i2r losses and giving more surface area to lower r.f. losses.

In the end you only get a few 0.xx % more power in the end fed antenna...
And we all know you need at least 3 dB difference to be noticeable on the other end.

For 20 meter it can be used, but there the antenna really runs out of the bandwidth it has, if you have no alternative, fine, but putting up a simple open dipole there will give better results.

I worked from 17 -10 all continents with 100 watts or less, even in the less good conditions of the last year.
Having the 5 meter long radials on the roof decouples the coax from the antenna and takes care of a counterpoise.

Half wave or 3/8 wave end fed antenna's have been around a long time and are studied enough to know all in's and out's.
Get a decent antenna book, i have the ARRL, RSGB, ON4UN low band dxing, And a gaggle others, and i.ve been playing with antenna's for the better part of 45 years.

There are no wonder antenna's out there, just good ones and some slightly less.
On 11/10 the size of the wire or tubing does make a difference in bandwidth, but also the way your network adapts the high impedance to the 50 Ohm coax.

My 160 meter inverted L starts as 80 mm tubing, or over 3 inches thick, fed at the base by the MFJ 998 and is used from 160-20 meters, together with the other OCF antenna fit for 160-10 meters.
The Imax 2000 has been on the roof for 9+ years and adds, as it was given for free, a nice alternative antenna for vertical DX on 17-10 meters.

Conditions are more important as the antenna, without them we don't make DX isn't it?
But it is always the best to put up the best antenna's you can get up, designed for the band and what you want to work as ham, n.v.i.s. antenna's for local work or beams and verticals for DX.

Always ask yourself what you want to reach with your antenna you are going to put up and then go from there.
There is no 1 antenna for all, to get the most out of a band you need multiple antenna's or just high multi element beams.

They do more as large linears, an antenna works 2 ways receive and transmit.
A large linear and a so so antenna makes you become a crocodile, big mouth, small ears...

I think we already have enough of these on the bands..., certainly in my side of the pond in Europe.

 

[BOOTY MONSTER]

""....... the thickness (or thinness) of the wire used does ......"

i was thinking that electrically the tubing would be seen as a larger diameter wire .

Nope the tubing is an insulator, it's only use is to keep the insides of the antenna protected from the elements (weather) and to allow the antenna to stand up."

i was referring to aluminum tubing ...... not the tube the fiberglass tube/radiodome to used to support the wire in a imax/antron/bandit .

 

[socal1leg]

arrived today

Needless to say the wife wasn't impressed. She said "that's not very long"

 

[hotrod]

i find the a-99 /imax are noisy on recieve. by that on quiet nights no dx /locals
i get slightly more white noise on these compared to my sirio 2016. these 3 were
tested on my 20 feet test pole using same radio,coax,ect. my 2016 is actually
hitting stations out 50 -60 miles away daily. nd im able to hear them without straing my ears.
tvi is also not there anymore using my 2016 ,in my tests nothing was changed but the antenna.so for me the 2016 was a better antenna and tuned better and im not meaning
covering numerous bands ,my dummyload will do that . the x was lowest on this antenna
at
x=0 on 11m
x=1 on 10m
the x was around a 4-6 on the a99/imax hmmmmm

 

[Justme]

The wire in the Imax 2000 is decent thick enough for 11 meters, we use wire antenna's on 160 - 10 of the same size, the higher the frequency used the more the size of the conductor matters for bandwidth, it is relative easy to use 1/2 inch elements and dipole for a 70 cm ( 450 MHz) beam, giving it a relative larger bandwidt as using 1/10 th inch elements and dipole.
Doing the same on 11/10 meters will make the radial material relative large, cumbersome, and unrealistic thick.
Here you chose the size of tubing for strength to withstand storm, not to widen the bandwidth.

So the wire of the Imax 2000 is good enough, the bandwidth comes from the used length of the wire and the network feeding the wire.
Using th same network and use 1" tubing would make the bandwidth fractionally larger but not much, the network used for transforming 50 Ohm to the high impedance end fed wire is realistically the limiting factor.

Even on 160 meter the 80 millimeter or over 3" tube as radiator used doesn't add to the bandwidth, i should then go to 1 meter or more, very unpractical.
I use the autotuner to adapt the L to the 50 Ohm coax.

What every Imax 2000 user can do to get the static from the antenna if you can open it up at the network feedpoint is using a 1 MegaOhm resistor over the C's so that the radiating wire has a 1 MegOhm resistor to ground in it's path, that will bleed static buildup to ground, the same as i use for my inverted L antenna, and Hi-end fed multiband antenna's.

Look at the opened up Imax story here on the board to see how the network of the Imax 2000 is made up.

The normal 5/8 antenna's have a long coil going from ground to the radiator, and the tap is chosen so that there the impedance is 50 Ohm, here the radiator has a short for static build up through the coil.

The network used in the Imax 2000 with 2 coils and the separating C's is the cause of the higher noise level for that antenna.
The radiator has no bleed off to ground so that static build up can occur on the antenna.

My Diamond X 510 for 2/70 vertical has the same smd 1 MegaOhm resistors over the C's that couple the 5/8 stapled sections inside the dome, bleeding static to the ground, as we did that on our X 7000 for our repeater 2/70/23 main antenna.
That repeater antenna is at 180 feet above ground and we had lots of static rain here causing trouble, this adding resistors to bleed the antenna took care of that.

 

[Assaulter]

so basically the Imax and the A99 are NOT going to perform better than a Vertical dipole cut for the band... IN FACT it will even be outperformed by a typical vertical dipole. WHY??? Well it's simple the Imax and the A99 are nothing more than a piece of wire and a matching coil to control the piss poor match

Apparently you need to read this... :

The Imax 2000 EXPOSED!