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Avanti Sigma4: An alternative view point
- Thread starter bob85
- Start date
The photo is quite clear on where L1 and L2 are, but I've no clue what the L3 refers to. There must be a missing page of instructions . . .
Marconi, I'm thinking I'll go ahead and use your gamma that utilizes the 1/4" rod and see what happens. I have materials for this one.
Marconi, I'm thinking I'll go ahead and use your gamma that utilizes the 1/4" rod and see what happens. I have materials for this one.
Thanks, SW
I don't have a ball, but I can slide the upper end in or out for tuning.
It appears from the 1310 mm and 1340 mm measurements of the radials that they are about 102.25" - 102.5" long.
I don't have a ball, but I can slide the upper end in or out for tuning.
It appears from the 1310 mm and 1340 mm measurements of the radials that they are about 102.25" - 102.5" long.
Homer, I just checked on the other forum and the guys over there are still ooin' and awin' about this old boy's new Vector. I doubt seriously I'll get any good measurements from him. The last measurement he sent me he referred to it as being in the ball park. That was reassuring.
Your figures for the radials @ about 102" + may be right. I estimated the length @ 106.8" based on the two elements being 2800 mm long with 3.5" of overlap only.
It might not make much difference, but I also notice that the Vector shown---indicates the hoop is located at the very tip of the radials and not .5" or more below the tip.
I think the natural progression for the taper of your tubing starting at 1.5" and ending with .5" is fine, but it may be the length of each segment that is also critically important to your getting a good match. My Sigma 4 has similar diameter tubing with 9 segments for the main radiator. I think the New Vector starts with a little smaller diameter tubing and has only 8 segments. How does this compare with what you have?
Just like Bob suggested, the mix and length of each section is also likely important to this setup. Here are the segment measurements for my Sigma 4 and not shown is the 88" bottom element. Sorry you can't read the dimensions, I had to resize the image too much. If you really need the info on this image, go to CB Tricks under antennas. It is listed with the Avanti antennas, even though it is from Antenna Specialists.
Good luck.
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Hey thanks Gents, I'll begin assembly today and hopefully, 'up in the skywave' by the end of the weekend.
I recently read a number of articles regarding ground wave and found 11m can have it, albeit shorter than most imagine. Typically I expect the term Ground wave is a misnomer which is widely accepted as slang by a vast majority of CB'rs and understood as the type of propagation which isn''t skip, sporadic-E, etc., kinda like someone saying to you, "What's up?" so you answer, "Looks like a C-141, several sparrows, cirrus clouds and a bevy of Dragonflies" when they were really just using socially accepted slang to greet you.
But it's good to know what's actual and accurate, however not everything is scientific, especially within this hobby!
Shockwave, thanks for the clarification and yet I wonder where the power level, and to what distance, ground wave begins to overcome the typical 11 meter, 12 mile limitations, as intimated by a couple websites I read.
Perhaps the term, "Surface Wave" might be a better one...?
One article mentioned a combination of tropospheric refraction, ground wave and even tropo ducting combining to offer 'usual' long distance comms mimicking ground wave, but I didn't save the url. I'll try to hunt it down later, after the antenna is up.
I will, of course, be testing it against specific meter readings taken while using the Penetrator, but the best test will be simply using it daily, and I should have a 'feel' for it within a few days / week.
I mainly enjoy morning QSOs with local (3-80 miles) Lsb Ch.38 operators, a couple of whom are a bit hard to pull from the noise on the P.500.
If the SigLarSaluVec IV000.150 can hear Doug without the addition of 'virtual enhancement' then it's a keeper.
To all, I apologize for being somewhat snappy lately, my best friend John WR-897 died suddenly, 2½ weeks ago from an aneurysm.
He was only 41, and it's taking a toll on my attitude in multiple different ways. Hard to deal with something so sudden and untimely. He left behind a wife and two children, 8 & 10.
I've had to begin practicing 'walking-it-off' a lot more lately than I used to.
73
I recently read a number of articles regarding ground wave and found 11m can have it, albeit shorter than most imagine. Typically I expect the term Ground wave is a misnomer which is widely accepted as slang by a vast majority of CB'rs and understood as the type of propagation which isn''t skip, sporadic-E, etc., kinda like someone saying to you, "What's up?" so you answer, "Looks like a C-141, several sparrows, cirrus clouds and a bevy of Dragonflies" when they were really just using socially accepted slang to greet you.
But it's good to know what's actual and accurate, however not everything is scientific, especially within this hobby!
Shockwave, thanks for the clarification and yet I wonder where the power level, and to what distance, ground wave begins to overcome the typical 11 meter, 12 mile limitations, as intimated by a couple websites I read.
Perhaps the term, "Surface Wave" might be a better one...?
One article mentioned a combination of tropospheric refraction, ground wave and even tropo ducting combining to offer 'usual' long distance comms mimicking ground wave, but I didn't save the url. I'll try to hunt it down later, after the antenna is up.
I will, of course, be testing it against specific meter readings taken while using the Penetrator, but the best test will be simply using it daily, and I should have a 'feel' for it within a few days / week.
I mainly enjoy morning QSOs with local (3-80 miles) Lsb Ch.38 operators, a couple of whom are a bit hard to pull from the noise on the P.500.
If the SigLarSaluVec IV000.150 can hear Doug without the addition of 'virtual enhancement' then it's a keeper.
To all, I apologize for being somewhat snappy lately, my best friend John WR-897 died suddenly, 2½ weeks ago from an aneurysm.
He was only 41, and it's taking a toll on my attitude in multiple different ways. Hard to deal with something so sudden and untimely. He left behind a wife and two children, 8 & 10.
I've had to begin practicing 'walking-it-off' a lot more lately than I used to.
73
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eddie, mm200 picked up a new style vector yesterday, i will try and get measurements if the guy on the other forum can't figure how to operate the tape measure,
007, i don't have any exact measurements, i tune for max signal and doubt the same measurements would suite everybody,
i can give you ballpark figures, the original vector 7/8 worked best at this location somewhere between 30' and 30'-6" with the stock 4 radial sleeve set as long as possible
the same sleeve on the fatter avanti monopole came in somewhere between 29'-6" and 30' as far as i can remember, i expect different locations and mounting height would need different measurements
007, i don't have any exact measurements, i tune for max signal and doubt the same measurements would suite everybody,
i can give you ballpark figures, the original vector 7/8 worked best at this location somewhere between 30' and 30'-6" with the stock 4 radial sleeve set as long as possible
the same sleeve on the fatter avanti monopole came in somewhere between 29'-6" and 30' as far as i can remember, i expect different locations and mounting height would need different measurements
Very much a better adjective as surface wave covers both ground wave and line of sight comms,which predominate at 27 mhz.At higher hf frequencies the actual ground wave portion is very limited due to ground absorbtion.
tropospheric ducting would come under skywave propagation like sporadic e,f1 and f2 layer propagation,auroral scatter modes etc,theres also a type of ducting found close to water,which for arguments sake i'd call sea ducting,similar effect to tropospheric ducting,all of which can take place on 11m.
To all, I apologize for being somewhat snappy lately, my best friend John WR-897 died suddenly, 2½ weeks ago from an aneurysm.
He was only 41, and it's taking a toll on my attitude in multiple different ways. Hard to deal with something so sudden and untimely. He left behind a wife and two children, 8 & 10.
I've had to begin practicing 'walking-it-off' a lot more lately than I used to.
73
I'm very sorry to hear of the loss of your best friend,had i known i personally would have been a lot less stroppy in previous posts,my sincerest condolences and sorry for being a retard in a tough time for you.
eddie, mm200 picked up a new style vector yesterday, i will try and get measurements if the guy on the other forum can't figure how to operate the tape measure,
007, i don't have any exact measurements, i tune for max signal and doubt the same measurements would suite everybody, i can give you ballpark figures, the original vector 7/8 worked best at this location somewhere between 30' and 30'-6" with the stock 4 radial sleeve set as long as possible the same sleeve on the fatter avanti monopole came in somewhere between 29'-6" and 30' as far as i can remember, i expect different locations and mounting height would need different measurements
Yea Bob, you must have seen that thread over there where the guys play with themselves to much. I'll wait on Multi-mode's measurements, he would be far more accurate. Most of those guys don't know what diameter means.
007, ole' Bob is not very encouraging about the possibilities for your success, considering that different locations and heights need different measurements, right? I wouldn't let it discourage you though, cause he also said several other buddies showed similar results in maximizing the Vector 4000's performance over the stock setup.
Can you wait for mm200's measurements? Personally I don't find the Sigma 4 design to be easy to tune physically and until the New Vector came out there never was much tuning information supplied with these antennas. At best most were set it, and forget it.
Unless you have a good mounting setup that allows you to get up high enough on this long antenna, it can be difficult to reach the whole gamma setup area. Tuning while mounting depends a lot on your being able to safely reach the top and bottom of the gamma area without having to take the thing down, which can also be a chore. Just plan you mounting carefully.
Homer, If i was on a boat in the middle of the ocean and the motor stopped running, and had NO spare parts...... I would look for YOU to come make it run....you have an uncanny knack of finding ways to make the materials at hand work somehow.
73
Jeff