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Never suggested that the value of the s-meter is not negated. Put it another way, the value that operators in general placed upon the s-meter is questionable. Ears unfortunately aren't reliable. On FM it doesn't take much to get a signal to be fully quietening due to the limiting effect. On AM or SSB, the AGC can "normalise" the audio volume.
But there is good news as if the s-meter readings are measured with a good quality calibrated signal generator, then a chart can be produced to have quantitative measurements. Or at least set the s-meter S-9 to 50uV at 50ohms (-73dBm).
As I said:
Unless calibrated, s-meters are just qualitative devices to give an idea of what's going on with reception, a useful guide and no more.
One example for CB is that it's very useful to have a s-meter on a rig, as gauging the relative signal strength of noise (static, PLT, Olga etc) gives the operator a feeling of how well the distance of possible contacts will be that moment. Not forgetting if yer good buddy 5 miles away is low in signal strength than normal, something isn't probably right. For VHF/UHF two-way comms, s-meters are generally not used as the noise level are usually low and more consistent.
73 from Dave the Pixie - 26CT052 - 26TM552 - CB Radioaficionado
"the value that operators in general placed upon the s-meter is questionable."
I don't personally agree. Whilst cheap (or expensive) radios may not be calibrated they are hugely valuable, that is the very reason they exist !
I have no idea of what you are saying other than they are often not calibrated. 1,000 anecdotal reports of extra 1S (even S +1.5 reported) point gain with the best 5/8 wave antennas still means a likely dB average between 3 and 6 dB (let's say 4.5dB even though the scale is logarhythmic) that information is far from invaluable.
Yet theory suggests that you may get 1.5dB over a dipole (ref) from a typical 5/8w antenna.
You obviously read a lot of theory. If someone replaces a 1/2w with a 5/8w and gets up to 6dB extra gain, then it shows you what a load of crap that 1/2w design or set up was in the first place. Plus terrain is important in its effect of the radiation pattern. What may be 3dB extra in one direction may be no difference in another. A very common scenario.
Most anecdotal reports made on CB is so way off and so unscientific its bull$h!t.
Reminds me of the 80's and a so-called antenna expert used to go around the local breakers sticking their antennas up. And people would say wow what a difference so 'n' so is such an expert. Yet what really happened was that he would stick up a Thunderpole 3 where there was previously a DV27 on a biscuit tin, and QED what a difference. In reality he had hardly any actual antenna knowledge and continuously made up nonsense about antenna theory. Those of us that had some technical knowledge regularly fail off our perches laughing
If you are really going to test the performance of an antenna in real life, you need a reference antenna connected to a calibrated RF voltmeter/receiver and measurements taken at given distance and height. No wonder antenna manufacturers get away with crazy claims.
73 from Dave the Pixie - 26CT052 - 26TM552 - CB Radioaficionado
I read a of of breaker reports and tests (and couple this with what people say who crack out on-air). That is good enough for me, real world users of said antennas.
RadioDaze wrote:I use the Gain Master and I like it. I am not sure about the performance claims yet and have had it about 3 months and being using it mobile static. For some reason I can only get a SWR of 1.5 or 1.6 : 1 whereas my 1/2 wave silver rod goes 1.1 : 1 with ease. I am going to try and test the Silver Rod out in similar conditions in weeks to come. As I change location it is more difficult to get a like for like impression against other verticals.
In saying this (and it might have happened with another antenna) my longest distant contact was to Indonesia and using the Gain Master.
I am trying to base performance considerations on long distance UK point to point line of sight / ground wave contacts. It is a work in progress.
Whatever it does the job well and in my mind is one of the top 3 performing vertical 5/8 length antennas in existence.
They work well but that will be a relatively small performance increase relative to other good 5/8 wave length antennas.
Some report 6dB differences (that is a lot for just an antenna change and much more bang for buck than going from 100W to around 500W which is what you need to get a similar gain increase) 1 S point.
So if the Gainmaster is in the top 3,what are the other 2 best antenna without radial's,maybe the Imax 2000 will be in your 3 ? I use a A.B.S. 1600 and it work's ok for me.
Plenty are talking worldwide on 27.555 usb,
Some are too far up their own @rse to admit it,
Many happen to know otherwise dx-ing test free,
Showing a complete lack of respect for the law.
RadioPixie i don't see the GM as a collinear, it looks like a 5/8 wave or thereabouts coaxial dipole with stub matching and a cap to give a wider than normal dipole bandwidth, look at the x-pole widebanded j-pole antenna.
W8JI
"An antenna with a poor ground using few radials cannot have a support mast grounded to the radial common point (at least it shouldn't if designed properly) There is no exception to this!
RadioDaze wrote:I use the Gain Master and I like it. I am not sure about the performance claims yet and have had it about 3 months and being using it mobile static. For some reason I can only get a SWR of 1.5 or 1.6 : 1 whereas my 1/2 wave silver rod goes 1.1 : 1 with ease. I am going to try and test the Silver Rod out in similar conditions in weeks to come. As I change location it is more difficult to get a like for like impression against other verticals.
In saying this (and it might have happened with another antenna) my longest distant contact was to Indonesia and using the Gain Master.
I am trying to base performance considerations on long distance UK point to point line of sight / ground wave contacts. It is a work in progress.
Whatever it does the job well and in my mind is one of the top 3 performing vertical 5/8 length antennas in existence.
They work well but that will be a relatively small performance increase relative to other good 5/8 wave length antennas.
Some report 6dB differences (that is a lot for just an antenna change and much more bang for buck than going from 100W to around 500W which is what you need to get a similar gain increase) 1 S point.
So if the Gainmaster is in the top 3,what are the other 2 best antenna without radial's,maybe the Imax 2000 will be in your 3 ? I use a A.B.S. 1600 and it work's ok for me.
Hi man, it does not really matter what I think, we all know the big vertical ones, over and above the basic GPA's and Silver Rods (And sirio variations) in most peoples budget area.
Gain Master
Imax 2000
Antron 99 (copes and variants included Thunderpole etc.)
Are surely the most popular and all performing about the same in the wide range of situations people use them in.
I am 100pct sure the ABS 1600 does alright. For me the more informative tests regarding antenna performance is long distance in the UK. I can only compare my own 2 antennas really. One day I will compare the Gain Master against the humble silver rod on the same pole. Possibly this week if I can take the time and effort to do it.
ian wrote:Still none the wiser, anyone know where the Gain Master originated from lol.
I think it is fair to say that the antenna is a new design. Yes other antennas have some of the characteristics of the GM but given it has a coaxial element, silver plated coaxial matching stub, capacitor coupling to top element and a choke it is actually unique unto itself.
One thing that seems to be emerging is that due to it being a balanced antenna (i.e. essentially a centre fed dipole) I have had a few odd experiences with using it mobile static of late. The SWR changed (and it is a non tunable antenna) from 1.2:1 to 1.6:1
It turns out that using it on a tripod kept the SWR low and but putting it up higher above my motor the SWR increased. So I am thinking that it is not liking having a car under it. Prior my tripod was 3m off to the side so out of the way a bit and the car was not directly below the antenna. Apparently metalic objects nearby can have a capacitive effect and cause mayhem with the radiation patterns etc.
I think the Gain Masters need a lot of height before they start giving the gain in the specs. It could be showing itself to be an antenna that is more fussy about placement near large metallic bodies. All antennas do to a degree of course but because the design is balanced it means this can potentially negatively affect performance more so than other verticals like Silver Rods and the multitude of other verticals that are not pseudo dipoles.
Something to at least think about.
I do not know any other person using a GM mobile static so I cannot get much input on the matter. If I find out the SWR lowers when I try and bung more polage under it I will report back. My next plan is buying more poles and some substantial guying.
Here seems to be some more information on someone who seems to understand why the GM actually produces gain over a "normal" 5/8 wave. From someone called Shockwave (to credit them)
"Having just replaced a Vector 4000 with the Gain-Master, I can't tell them apart in terms of signal. The GM does have more bandwidth but less power handling as of now. The wide bandwidth on the GM maintains it's gain over a larger spectrum with no tuning. Another advantage is the antenna has extremely low wind loading when compared to a Vector or 5/8 wave ground plane.
If you can keep a Vector in the air and it's bandwidth meets your needs, there is no point in replacing it with the Gain-Master. However, there are lots of people who can use the large Vector. If your power is below the rating of the antenna, the GM is a great alternative that looks like it will hold up to the weather. Seeing how it compares virtually identical to a Vector means it's going to have more gain then any other 5/8 wave.
I am shocked to say the least that a fiberglass stick would reach the level of performance of the Sigma design. That is what it's doing at my location and it seems others are seeing the same. That also means those $400.00 5/8 waves are going to produce a gain that is indeed noticeably lower then the GM. There are only two omni antennas that perform like this and the reason behind the gain is clear.
Verticals that are end fed inherently start producing counterproductive radiation in the lower portion of the radiator when it's wavelength is beyond 1/2 wave. Both the Vector and the GM have been designed to eliminate the effects of this destructive base radiation and replace with radiation that reinforces the far field gain. In simple terms, the Vector does this with it's cone that sheilds the "bad radiation" at the base of the raditor and replaces it with "good radiation" from the cone.
The GM avoids the entire issue by center feeding a 5/8 wave radiator. This changes the distribution of the radiation currents along the antenna in such a way that all of it reinforceses the far field gain. With this ballanced 5/8 wave that is split in half, the radiation currents never see enough length to produce a phase angle that is deconstructive. When you use the antenna, the advantages are easily confirmed.
You will see that when all of the radiation currents along the length of the antenna are phased to add gain, signal goes up in the distance over all other 5/8 wave or less antennas. Some have seen local signal gains. I notice the gain in the distance. The GM is awesome with RFI too. In order to center feed the radiator, Sirio had to essentially eliminate any possible radiation from the coax and mast. They did achieve this."
