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UPDATE ON A99 VS. I MAx 2000 AT 12'

Stellasstillarat

Active Member
Aug 14, 2014
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After the nightmare that was caused after I cut 30' of extra LMR 400 I almost gave up.
I sent my coax to my tec, along with a few other pieces of equipment that needed attention, and he replaced the pl259 that I installed then removed it and did it again.
Obviously both of my pl259 soldering jobs were so poor, it led to high swr and other issues, that I've gratefully forgotten about.
I went with the I max 2000 on three 5' masts.
Added an MFj 915 using a dubble pl259 male connector, which put it as close to the antenna as possible.
My swr is 1.1:1 and along with the output no longer changes from channel 1 through 40 (or free bands).
The swr warning light that would flicker while I modulated, even though the swr was no where in the danger zone (but higher then it is now), has ceased.
I belive the MFj 915 rfi choke took care of that stray rf making it's way into the shack, causing the cheap warning light circuitry, activating the warning light.
I thought the Madison's receive was decent with the a99 because, I'd never used a transistorized rig except for my first mobile rig run with a radio shack 12 volt power supply and a mobile antenna sticking out of my bedroom window.
Everything after that was tube and yhe I've always thought tube radio recive to be superior over transistorized.
I must ssy the recive on the madison is incredible for a cb rradio.
The difference between the I max 2000 comparied to the a99 has not only gained me one + s-unit on my recive, but it's much much quieter.
Really a joy to listen too.
As for my signal on the other end, it took a few days, but eventually stations who knew my signal while using the a99 begain to ask if I'd done somthing different as my signal was a bit higher then when It was before the antenna swap.
As far as dx'ing If I hear them 99% of the time they hear me.
My reason for mounting my antenna on three 5' masts in my backyard is because I have a brand new roof and siding.
I don't have a chimeny and drilling into my new roof or siding was out of the question.
The double nuvista front end on the sonar fs2340 is also quieter and truly sweet to listen too .
Like the madison I thought the recive was fine with the a99 but I hadn't been on the air since 87.
Eight months ago I setup my station and just forget what the recive on my sonar sounded like with my sigma 4 on top of a two family home and and a 10' mast.
I really appreciate everyone's help through out this difficult period. The MFj 828 that I was warned about purchasing works excellent. I guess I got lucky. I also purchased the MFj 1500 watt dummy load.
Being the I max is only 12' off the ground I still use the Maco 150 preamp, but unlike with the a99 (it was on all the time) it's only used when I make a contact who's giving me 5 by 9 report, but their station or one way conditions is just not making the trip and low to enjoy a qso without putting my ear to the speaker.
Just a 1/10 turn of the maco's gain knob solves that problem.
I'm truly ecstatic.
As far as rfi, as with the a99 still not one complaint from nabour's.
I have one place on my home that I'd have no problem using screws to install my antenna.
That's the eave.
I will wait until spring time to purchase an eaves mount and install the antennas there.
I will only put the imax on a 5' ft mast as I'm not interested in having to use guy wires.
As of now the whip section of my I max is peaking above my roof line by about 6 ft.(not good I know).
I'm positive the eaves mount will greatly improve the current operating abilities of it at 12 ft off the ground.
The whole antenna will be above the roof line by 3 ft.
I could do that now as the weather's perfect, but I'm enjoying the little skip that's begging to roll into south Jersey and I don't want to push my luck.
As i mentioned I get excellent audio and signal reports with every contact.
As a matter of fact every single station I've shouted out to has not only heard me but many unsalicited positive reports.
I've yet to hear a dx station that hasn't heard me.
I know I've said it but I'll say it again.
The difference between the I max and a99's is big.
I enjoyed the a99 and it worked well while I was using it, but the I max is a pleasure.
If there's an aluminum vertical antenna that doesn't need ground planes I will concider purchesing one for the spring 2016 eaves mount above the roof line project, please let me know if you use an aluminum vertical with no radicals. I don't even know if that type of 11 meter antennas available, but if so please weigh in. Thank to everyone who's helped. Much appreciated. 73
 

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Last edited:

i'm not completely clear on your mounting issue yet, but i'm thinking a couple of antennas:

Astro Plane
Sigma 4
Gainmaster

the astro plane may work the best for you if i follow that this will be a low to the ground mount:
as the other 2 may be top heavy in such an install if i'm following you
 
If I had my Imax feed point at 12ft I would not have been able to talk to 853 Australia barefoot. Min height the feed point should be is like 22ft to 24ft
 
If I had my Imax feed point at 12ft I would not have been able to talk to 853 Australia barefoot. Min height the feed point should be is like 22ft to 24ft

Yes you could have. Maybe not at that particular time but skip is a poor way to judge an antenna. A few minutes later conditions can change and you couldn't make it with the antenna at 100 ft.
 
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If I had my Imax feed point at 12ft I would not have been able to talk to 853 Australia barefoot.

Yes you would've. If I could work the Falklands Islands 8000 miles away whilst parked outside a fish and chip shop on the high street in my home town in Northern England using a mobile antenna then you can manage Australia barefoot at 12ft.

Height differences, well sensible ones, for long range DX for a vertical antenna makes not a lot of difference, maybe a S point to be gained but not enough to be a make or break for making a contact on SSB. Certainly the difference between 12ft and 24ft would make no noticeable difference. Local contacts would be an entirely different story.
 
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I've made sevral contacs to Australia, southAfrica, eactcoast of Turkey. Antenna hight for skip is inconsiquntial. Mobile'swith 102" whips do it all the time. And their only 4' off the ground. Do I transmittt 12 watts? No, but if conditions are there anyone with a long wire would have a shot. Conditions conditions conditions. 73.
If I had my Imax feed point at 12ft I would not have been able to talk to 853 Australia barefoot. Min height the feed point should be is like 22ft to 24ft
 
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Instead of taking a Triazolam, I just read this topic, worked like a charm. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ.
 
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Always happy to help.
If this op doesn't do it for you check out some of my other postings.
There sure to put you out like a light. 73.
Instead of taking a Triazolam, I just read this topic, worked like a charm. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ.
Instead of taking a Triazolam, I just read this topic, worked like a charm. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ.
 
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