Modified Vector 4000

[bob85]

The 6mtr vectors are the first antennas i tested using the rsp1a for signal strength Eddie,
i used various methods to see signal change in the past but nothing in calibrated quantifiable units,

50mhz is a great band for experimenting, the antennas are much smaller & that turns what was a weak & bendy 27mhz antenna into a strong stiff antenna,

all that comes to mind with regards to dx about the i-10k was at the low height i had it installed, short hop skip into places like iceland was better while longer haul skip & local signals were not as good as the vector,

i don't think i ever thought it picked up horizontal signals any different from my other verticals but there's nobody local using beams & dx signals get skewed so i would not notice,

is this horizontal radiation you see wasted energy that should be vertical polarity ?

The astroplane was on the same pole & coax as the gain-master making the gm significantly higher so naturally my signals to and from everybody local within 40miles have gone up,

i have not done any 27mhz antenna testing to post about, been playing on uhf & vhf away from the headbangers & music players.

 

[bob85]

Today i noticed my vswr on the 3/8 cone Vector was higher than usual, the dog has been out for a look & can't see anything wrong that could cause a problem & my wife won't go out in the snow to adjust the gamma ?

i don't know what to do next,

 

[Marconi]

Hey Bob, how did you determine the location of the dog bone on your 6 meter version of the 3/8 wave cone on the Vortex?

I tried to scale the antenna and for the most part everything except for the physical gamma was about right at 27.205 and 50 MHz.

Just curious.

 

[bob85]

I had it tuned pretty close with the 1/4wave cone Eddie,

not having my analyser to use i recalled the ARRL open sleeve antenna article i posted about years ago,
i presumed extending the radials & reducing the angle & spacing to the monopole would lower the feed-point impedance

i went looking for 50ohm a little higher up the monopole & found it,

I moved the gamma strap up in small increments & adjusted the gamma capacitor for lowest vswr each time until vswr was low again,

neither of them were tuned perfect but less than 1.2:1 on my old kenwood sw200a,

you can achieve a low vswr over a wide range of monopole and cone lengths.

 

[Marconi]

My model has two wire for the radiator length of 343.76". This is because Eznec requires wires to only connect at wire ends.

So, from the base to the dog bone wire #1 is 60" at 27.205 MHz.

Wire #2 = 283.76" + Wire #1 = 60" = 343.76" for radiator.

60" / 343.76" = 0.1745% is the space to the dog bone.

I did the same thing that you did to find the point for a good match.

My model is a little long in the length, but I probably averaged the overall radiator diameter wrong, at 0.73", and the tune covered up the error.

 

[davev8]

Today i noticed my vswr on the 3/8 cone Vector was higher than usual, the dog has been out for a look & can't see anything wrong that could cause a problem & my wife won't go out in the snow to adjust the gamma ?

i don't know what to do next,

here on the lincolnshire coast we just got rain and then some more ....its still raining

Today i noticed my vswr on the 3/8 cone Vector was higher than usual, the dog has been out for a look & can't see anything wrong that could cause a problem & my wife won't go out in the snow to adjust the gamma ?

i don't know what to do next,

 

[bob85]

yep, no snow in Hull either but we had cars blocking roads here with a few inches of snow.

 

[Marconi]

Bob, I think you mentioned a few days ago that one of the Q82's had a radiator that was 0.82 wavelength. Which model had the radiator that long?

 

[bob85]

The mk1 q82 had a longer monopole @ about 28' 2", its not .82wave,

when you sweep the radials up towards the monopole it raises resonant frequency/ electrically shortens the monopole,

The q82 mk1 is about 4" longer than a 3/4wave new vector 4000,
& its got fatter radials raising its resonant frequency more than the skinny vector radials,

its electrically closer to 3/4wave imho.

 

[bob85]

The claims and actual measurements for both versions of Q82 are as of recently only available on wayback machine Eddie,

looking at the Q82mk1 you will see that they call it a .82wave but look further down at the antenna height @ 27.500,
its only a tad longer than a Nv4k and it has fatter radials at the same spacing
making it look a little shorter electrically,

it is not a 29ft+ .82wave antenna on 27.500mhz as claimed

The mk2 comes in two versions,

version 1
has a 10" shorter monopole than the mk1,
it has a 3/8wave cone with 1 set of spreaders up near the hoop,
the hoop is 3" smaller in circumference than the mk1

version 2
Had a modified taper schedule using longer 38mm & 30mm lower monopole tubes so that the upper spreader clamps to a larger diameter tube & a second set of spreaders were added lower down to keep the long radials more accurately spaced to the monopole in wind,

regardless of what the advertising claims none of them are .82wave antennas on 27.500mhz.

 

[Marconi]

@bob

Sorry I deleted my post. I saved it by mistake and I was trying to do an edit and I deleted it by making another stupid mistake...hitting the wrong button.

I'm just trying to get my details together for what antenna is being discussed, what the dimensions are, and at what frequency (or range) the kit provides.

1st I wanted to try another model of the Vortex Q82 Mark2 to see if I missed something in my earlier models.

Then I wanted to try the Vortex Q82 Mark 1, but I don't have any good dimensions or the frequency either.

Just too much BS in the details here to know what the dimensions for the Vortex antennas is. Same for the vague results they published too. If I'm wrong maybe DB can make his model of the Q82M2 and prove me wrong.

So Bob, I'll wait until you're able to post your real world dbm results when the weather clears for you.

 

[bob85]

The cone & monopole lengths for resonance @ 27.500 for both versions of Q82 are clearly listed on Vortex's website available on wayback machine,

you have modeled the mk1 dozens of times without realising it Eddie,
i think the confusion is they called it a .82wave when its not

The mk1 cone hoop & monopole lengths are so close to the Nv4k with its little ball hat that you have to look elsewhere for what makes them different,

Q82 differs in its use of larger diameter much thicker wall tubes with a different taper schedule & larger diameter gamma using polyflon ptfe dielectric.

the dimensions are so close if you want to see a difference you will have to model the proper tube diameters & schedule, that's all that makes them not the same antenna electrically.

 

[Marconi]

You're right Bob.

I've never been real sure these Vortex models were to specs, and I know using good specs can make for a more accurate model, but I don't know if it will make the difference this bunch might tend to report showing big gains. This is why I want to model the Q82M1 again.

I might even try and use taper in the radiator and the radials just to get a base line and compare taper to no taper again. So, again I might have to make some estimates for some of the individual tube lengths in their stacked setup they refer to as "Vertical Radiator Stock" with 6 pieces.

I'm just guessing if the images are close, I would say the 2 bottom tube are approx. 75" inches and the other 4 are close to 45+" inches for the 6 tubes. This is close to 338," So, I'll make the tubes fit into 338." I don't want to change this length, at 27.500 mhz, in the gamma tuning process.

I think I will also model this Q82M1 with what I call "simulated match" where I just find 50 ohms on the bottom of the radiator somewhere, and then try and match it as an End Fed too, like I think they showed us in their Vortex paper work for the Q82M2.

That said, I don't have the taper outside diameters...unless you or somebody else has some tips that will get me closer for this long tubing.

 

[bob85]

since the hoop cone & monopole are so similar in length to a Nv4k i will list the things that are different,
it won't help you make a good model,

The tube diameters for the mk1 radials are 16mm & 12.7mm
mk2 radials version 1 & 2 use 20mm 16mm & 12.7mm,

vector uses 13mm & 10mm,

you can see from oggy's video review on the Q82 mk2 version1 that they did not use equal length sections,

we also know that on the mk2 version 2 they extended the 38 & 30mm lower tubes so that the spreader clamped to the 2nd section & not the 3rd section shown in oggy's video,



The lowest part of the monopole inside the cone is 2" / 50.8mm box section stepping down to 38.1mm tube, & 30mm tube
vector uses 33.5mm & 30.5mm lower tubes

Vortex gamma is 16mm & 9mm
vector gamma is 13mm & 6mm,

these seemingly small details are what makes the a Vortex Q82 mk1 different to a vector & all the other sigma4 clones sold in cb shops,


i don't believe those differences make a Q82 mk1 consistently 2 s-units up on a vector 4000 unless other factors were screwing the tests up in a major way.

 

[Marconi]

The cone & monopole lengths for resonance @ 27.500 for both versions of Q82 are clearly listed on Vortex's website available on wayback machine,

The key to my getting good dimensions hangs on one big factor that few folks mention, and most don't consider when (bless their heart) they go to the trouble of getting me dimensions, and I'm thankful for that. That is, that the frequency is seldom noted along with the dimensions in these discussions. Bob you are right, Vortex does show us a frequency.

you have modeled the mk1 dozens of times without realising it Eddie, i think the confusion is they called it a .82wave when its not

In my efforts to model the Q82M2 I never considered if the radiator was 0.82 wavelength or not. My mistake in most models back then was getting the radiator length to work at 27.205 MHz, which is our CB frequency in the US, and trying to use these dimensions without knowing the frequency for those dimensions.

Sometimes I might also make a change in the radiator length to make the model resonant, and that would a mistake too. Then going back after days, weeks, or months and using the same model out of convenience. I call it modeling "error creap."

The mk1 cone hoop & monopole lengths are so close to the Nv4k with its little ball hat that you have to look elsewhere for what makes them different,

I have model the Vector 4K using the Top Hat, but it is a pain to making adjustments. having to try and fix all the extra wires, so I typically make the model without the Top Hat and that too can develop into a bone of contention about a model.

Q82 differs in its use of larger diameter much thicker wall tubes with a different taper schedule & larger diameter gamma using polyflon ptfe dielectric.

Sometimes folks provide me with the wire lengths, but seldom do I get the wire diameters.

Eznec also warns against using taper and that always raises questions I can't effectively answer if I'm asked. So taper is generally not modeled and thus I have to estimate the radiator and other wires average diameter...and this can cause issues too. So it is often a vain effort to try and model some of these antennas and for sure the Sigma4, and Sirio Vector, and other ideas along these lines.

since the hoop cone & monopole are so similar in length to a Nv4k i will list the things that are different, it won't help you make a good model,

So Bob, at this point, I would say: let "Mikey" do it.

For you folks from Reo Linda...check out the link below.

www.youtube.com/watch?v=CLQ0LZSnJFE