gainmaster vs i10k a quick test with locals

[bob85]

me and a few locals did a quick unscientific test today, my i10k vs a new gainmaster on the same short mast, feedline, radio ect, we used my jfk foxhunting radio with 4-1/2" external s-meter and rf gain up full,

using 27.76125mhz fm no audio signals were stable ( no skip no flutter )

the antenna not under test was layed on the ground away and @ 90 degrees to the antenna on the mast, we swapped in a timely manner while everybody waited to see the results,

the tenths of s-units are our best guesstimation of what the big meter was reading on our end,

tx signals are low due to the receiving stations reducing their rf gain to make any change in signal easier to observe,

 

[HomerBB]

What a deal. :blink:

You wearing hard hat?

 

[tecnicoloco]

What a deal. :blink:

You wearing hard hat?

Testing,testing,1,2,3,radio check :w00t:

 

[BOOTY MONSTER]

looks like jays i10k tied one transmit comparison , but won every other tx and all the rx test . opposite of what mostly gets reported over here . i can hardly wait to read your report on how it compares with your modded vector or sigma 4 .

 

[cbradiomagazine.com]

Let's make a fun non-scientific assumption.

If the $60 A99 is the entry level base and you want to upgrade -

1 S unit increase = $40 (Imax)

2 S unit increase = $119.95 (Gain Master)

3 S unit increase = $279 (I10K)


We now can quantify dollars to S units for vertical 11 meter antennas.

 

[Meglotron]

me and a few locals did a quick unscientific test today, my i10k vs a new gainmaster on the same short mast, feedline, radio ect, we used my jfk foxhunting radio with 4-1/2" external s-meter and rf gain up full,

using 27.76125mhz fm no audio signals were stable ( no skip no flutter )

the antenna not under test was layed on the ground away and @ 90 degrees to the antenna on the mast, we swapped in a timely manner while everybody waited to see the results,

the tenths of s-units are our best guesstimation of what the big meter was reading on our end,

tx signals are low due to the receiving stations reducing their rf gain to make any change in signal easier to observe,

you said you used a short mast. how short?

 

[Marconi]

me and a few locals did a quick unscientific test today, my i10k vs a new gainmaster on the same short mast, feedline, radio ect, we used my jfk foxhunting radio with 4-1/2" external s-meter and rf gain up full,

using 27.76125mhz fm no audio signals were stable ( no skip no flutter )

the antenna not under test was layed on the ground away and @ 90 degrees to the antenna on the mast, we swapped in a timely manner while everybody waited to see the results,

the tenths of s-units are our best guesstimation of what the big meter was reading on our end,

tx signals are low due to the receiving stations reducing their rf gain to make any change in signal easier to observe,

Way to go Bob, but I sure wished you were able to test your Vector too.

How high were the antennas and how far away were your contacts?

I just posted a recap on all of my 2010-2011 signal reports in another thread the other day, and I was surprised to see the GM so far down the list, albeit again all the antennas were very close together in RX signals. Even so I think, for several other important reasons that the GM is by far, the best CB vertical I have here.

I recall when I first got my GM, I set it up right away on a 10' foot mast and attached it to my fence for support, and it didn't work worth a hoot for me. In fact it was obvious to me that my AP and A99, which I had been playing with a little earlier, mounted in the same place, both responded better. I think I posted about this back then, claiming that the GM did not respond well low to the Earth. Seems like I remember someone else was saying the same thing about that time. I think Shockwave also told us that even though he wasn't initially impressed with his GM at first either, there was no problem with the GM being mounted low in height. However, I don't really remember if he told us why he was not impressed, so I don't know. In my case I thought the problem was due to the fact those antennas were not higher than the highest peak on my roof...which probably blocked off some of the signals. But after I moved it out back, I still didn't sense good performance, plus my bandwidth curve for it, mounted down that low, looked a mess as well...and I thought that strange. IMO, most antennas mounted down that low seem to flatten out the band width curve due to losses, and make the curve nice and smooth, but in my case that is not-so with the Gain Master.

So, if you were below about 20' feet and had that big old I-10K was laying below it, like I noticed in my 2009 testing with my AstroPlanes and they were higher at over 20 feet high, I would think that might really ill-affect the performance of the GM. IMO, since the choke works so well otherwise maybe the GM is very sensitive in that area as a result.

I remember you telling us a few days ago how you layed the test antenna down in some particular position, and at the time I wondered why you felt that necessary to even mention, especially in light of the fact we discussed my experience, doing something similar, several times over the last couple of years. Were you testing to try and duplicate my experience to see if such was duplicable? Maybe you remember, that I was really surprised at that response I noticed.

Personally and in my experience with my I-10K and its potential to produce common mode currents, I'm not surprised that you saw better close in local signals with the feed line being an active part of the antenna system. I think that is also why I see good results with my A99 and why so many see good results with their Imax setups.

 

[HomerBB]

It took a good deal of coordinating that many folks to get this done at the same time. That alone is a significant feat.
I am sure those results with the I10k pulling ahead overall are not what many think should have happened.

 

[Marconi]

Here is my RX only comparison testing for my I-10k vs GM and my Imax vs. GM, along with my Recap Report for fall and spring of 2010/2011 indicating how these reports ranked by averaging the Sunit signals. The two signal reports noted indicate that both antennas were mounted close to the same height to the coax connectors on each antenna. If I had included my I-10K/Imax they would have shown respectively 7.5/7.7 Sunits in the recap.

The result of this recap was a total surprise to me.

View attachment Gain Master vs. I-10K 011611.pdf

 

[jazzsinger]

me and a few locals did a quick unscientific test today, my i10k vs a new gainmaster on the same short mast, feedline, radio ect, we used my jfk foxhunting radio with 4-1/2" external s-meter and rf gain up full,

using 27.76125mhz fm no audio signals were stable ( no skip no flutter )

the antenna not under test was layed on the ground away and @ 90 degrees to the antenna on the mast, we swapped in a timely manner while everybody waited to see the results,

the tenths of s-units are our best guesstimation of what the big meter was reading on our end,

tx signals are low due to the receiving stations reducing their rf gain to make any change in signal easier to observe,

no major surprise 2 different types of 5/8 wave mounted at the same low mounting height produce roughly the same signals.

i think the bigger differences some people see, come down to certain higher mounting heights that favour either a gp type antenna or a dipole type antenna.

 

[MrSuburban]

no major surprise 2 different types of 5/8 wave mounted at the same low mounting height produce roughly the same signals.

i think the bigger differences some people see, come down to certain higher mounting heights that favour either a gp type antenna or a dipole type antenna.

I agree the antenna with ground radials lower to ground may have a slight advantage.

 

[bob85]

the test was only a quick test done at about 12 feet, it was a nice day so we decided to do a test before errecting the gm at its new home a similar distance above ground,
its possibly not what somebody with a tower would see but it gives my locals an idea of what to expect locally in a typical install here,

we also compared the gm to the a99 at its new location, the gm improved signals by about 1 s-unit over the a99, i could hear on my way home without looking at the meter that the gm filled in the hills and hollows notably better than the a99,


eddie,
i lay the antenna down well away so as to minimise any effect there could be, i have done that for over 25 years,

a question was asked could the aluminum stepladders be having an effect so a local walked around the yard holding the stepladders while we watched to see if the ladders effected the signal, they don't seem to be a problem.


booty,
i already know the outcome of that test in this yard if the NAPCO works as well as my hybrid

the gainmaster did better than my no radial imax in the same test,
a couple of local imax users assisting in the install have already decided the gm will be their next antenna.

 

[bob85]

jazz, mr s,
i agree, the test height was far from optimal for either antenna but it is roughly the height the owner uses his antenna@, i make no claims as to how the gm would compare when mounted higher or with very weak distant stations,

i could have reduced my rf gain to increase the difference seen on my meter as the receiving stations did,

the gm performed great for a no radial antenna.

 

[Meglotron]

Sounds like the gainmaster is the wrong antenna for alot of people. unless you put it up higher then 18 feet over everything maybe the interceptor is the best bet.

 

[BOOTY MONSTER]

i think whats underneath the antenna and how far it is from the antenna........can play nice with most antennas and and play a little nicer with a few others . and as that changes so will the nicer antenna winner change . since what underneath each of our antennas is different it seems sometimes its gonna be very small differences and sometimes detectable differences . its all about the lobes .... i think

but then again , on antennas with elevated ground elements/ground-plane elements , their job is to provide a a effective GP .