Thread Last Poster Posts Pages Last Post   Closed: New threads not accepted on this page

This area is for discussing the A99 Exposed review.

Author Message   Scrapiron63 Posted on Saturday, December 29, 2001 - 12:58 pm:        Good review, you are saying what I have known since shortly after they came out. I just don't argue it very much. Your review explains why the 99 causes so many tvi and other interference, the 'open air connection'. I have looked at many of them destroyed by lightning, there was a discussion on this forum about if they were more prone for lightning strikes, probably not, but a small hit will destroy them, where I have had other antennas hit several times, with no damage other than rotor or control wires. The big tall commercial towers get hit often, sometime with ever thunderstorm. At first they advertised the 99 with that 9.9 dbi crap, later they added 3.3 db gain, but I doubted that. That overstating the gain of antennas is pretty common, the companies that make Beams do the same, like JoGunn, they came up with those hellish numbers for their short beams. When the retail price of an antenna, like the 99, is about 40 bucks, you can imagine how much the manufacturer got for it, and how much design, material and labor he could afford to spend on them, like they say, you get what you pay for. I know people that spend 150 bucks on their mobile antenna, and run a 99 on base, go figure.   Honkytonkman593 Posted on Sunday, December 30, 2001 - 9:16 pm:        well i must say that i like my a 99 very well used it for years even though i had already seen the guts of one before. it works its simple, and you can hide it in a tree. this is why people like them. i found it to be better then my old aluminum egg beater top antenna i had run. it is handling 500 watts no problem. though ive had it at 800 at one time. when they go and make a stargun base antenna like my mobilr one ill get it but til then ill stick with my fiberglass small wire a 99 antenna. cant beat price/ or popularity of 99. oh and reliability of one . mines been up 10 years and its freying a bit but keeps on putting it out there. well just my opinion who care about claims i care about how well people hear me. thanks   Taz Posted on Sunday, December 30, 2001 - 10:15 pm:        i never have had an antron but im going to keep the imax   Marconi Posted on Monday, December 31, 2001 - 1:25 pm:        HamCber, did you write this review? Sure sound like ya! I just discovered this thread, maybe I will have something to add later. Marconi   Honkytonkman593 Posted on Monday, December 31, 2001 - 6:02 pm:        they should take apart the i max bet its the same principle. i look at it this way its cheap and it works well. thats all. later   Taz Posted on Monday, December 31, 2001 - 6:11 pm:        hey marconi i see your name all over the eei forum is that that same marconi as you?   Marconi Posted on Tuesday, January 01, 2002 - 2:26 pm:        Happy New Year to you guys. Yes, Taz, I post over there at times. It keeps me grounded in a little humility to go there and wallow-around a bit. HTM593, I have never seen the insides of the Imax either, but I suspect, as you do, it is probably very similar to the A99. I use to hate the A99's because of the often mentioned TVI they often get tagged with producing. I have owned several over the years and they always seemed to be a bit noisy compared to other antennas I worked. I have never worked the Imax but I guess it is about like my SigmaIV, except for maybe the bandwidth. I can get almost the same results with the A99 as these other bigger antennas if I get the tip up as high or higher. Everything considered, I don't believe you can beat the A99 and that type of antenna for all-around performance. Marconi   Tech833 Posted on Tuesday, January 01, 2002 - 3:11 pm:        If Copper sent me an Imax 2000, I would be glad to examine it and write about it! I have been designing and building antennas for broadcast and related industries for almost 20 years. I have not examined many CB antennas before, so it would be interesting to me also. The TVI people mention from the A99 very well could be caused when that coax is not soldered like in the 2 examples I cut apart. Bad electrical connections may generate all sorts of their own frequencies, some right on TV channels. If the coax center conductor were soldered on some but not on others, that may explain why some people complain of TVI being cleaned up with an A99 while others say it is worse. I plan to write more articles dealing with how antennas work. Keep an eye out for those. The series will explain the real theory behind antenna operation and dispel all the 'voodoo' beliefs relating to antennas and gain. Armed with the information I am going to share, you will be an antenna expert too.   Honkytonkman593 Posted on Tuesday, January 01, 2002 - 8:20 pm:        i do appreciate it cause i am really curious about the imax!! we all appreciate what every tech and everyone has to say and do related to cb and the equipment . keep up the good work guys and keep us informed!!   Marconi Posted on Wednesday, January 02, 2002 - 8:05 am:        833, some time back I posted some information about what I found when I removed the lower section of an A99. This particular antenna always seemed to produce TVI. I thought it worked very well otherwise, but it was dirty, dirty in the immediate area. I made a similar conclusion about the TVI problems being related to soldering. I found the pigtail that was soldered to the coils was not tinned very well if at all. In fact, some of the tiny shield wires were actually touching the center conductor wires. This made me curious as to whether this could be the cause of the bad radiation that this one seemed to make. I redressed the wires, added some additional wire to the radiator to replace the other two sections, hung it in a tree and radiated it with the feed point only about 5' above earth. There was still some TVI but it was noting like before. I then made some wires almost touch the center conductor and the TVI returned. It was remarkable. 833, I noticed a clear tube insulator, placed over the shield side in your picture at the bottom of the coil. There was no such device on my A99. I also noticed a small dark round device a short distance up the radiator. My A99 did not have that device either. I read another post somewhere that indicated that was an insulator. If true, maybe that might explain the ½-wave over a ¼-wave description that Solarcon gives their A99. I suspect that is just a spacer that helps keep the thing from rattling around in the lower section that may cause some to think it is broken? How is the continuity thru that area? What do you make of this item? I see this lower portion of the A99 as two separate but combined devices. One is the variable tuning coil that is one continues piece of wire wound into two coils, one inside the other, separated by an insulator that probably makes the step down in impedance to near 50 ohms. I see the other device as a variable gamma match device that simply insulates the feed point center conductor from radiator and matches the impedance at different frequencies. The question has been asked, "...what is the tuning range using the rings?" I always assumed that the rings simply moved you up and down frequency as Solarcon suggest. I just installed an A99 on a pushup pole to check that out. I am going to do some checking on what the tuning rings actually do when moving them up to the top and down to the bottom using my Autek VA1. I will be using a random 62’ foot length of Mini 8 coax with a .80 velocity factor, so assume the line may skew the results a bit. The feed point will be at 12’5” above earth and this too can cause questionable results. I will be looking for relative information only. With this setup my analyzer shows me that the characteristic that changes the most is the reactance. The best resonance I could get as I go down to the bottom with the rings was at about 25.420. The impedance showed to be 49-51 ohms, but the reactance went to –26j at 1.66 SWR. Going up is about the same to about 28.000, the R=53, with X= +1j and the SWR 1.04. So, the coil does seem to control the impedance match quite well but the reactance gets out of control as you go down in frequency. That may suggest that the coil works best in the higher end of its effective area. Marconi   Tech833 Posted on Thursday, January 03, 2002 - 2:32 pm:        Hi Marconi. The black 'device' a short distance up the radiator is a piece of foam! It was up near the center to keep the small diameter copper wire from rattling in the lower section. It slid around when I took it apart. "I always assumed that the rings simply moved you up and down frequency as Solarcon suggest" Yes, they do. Since the resistance is fixed (the inner coil provides the resistance tap), the tuning rings getting closer to or further from the outer coil affects the value of that coil. In this configuration, the coil is being used to cancel out the capacitive reactance created by the coupling capacitors. Adding more inductance in series between the feedpoint and the radiator's series capacitance will lower the frequency of this low Q transformer while taking away inductance will raise the frequency at which the inductance is more critical. It is a very low Q transformer we are talking about here. Coaxial cable length or velocity factor will have almost no effect on the values. I used an IFR 1200 Super S to sweep the antenna and figure it out. I also measured the inductance of each of the coils and the capacitance of the brass sleeves and plugs. Doing all the math, it worked out. However, the wide bandwidth of the A99 comes not from a high Q design, but rather from 'variable loss' in the feed circuit. I have more antennas on the way which will be the subject of more articles. Keep your eyes open for them!   Highlander Posted on Thursday, January 03, 2002 - 5:51 pm:        Tech833, who are you? You seem to really know antennas--Have we heard of you? Are you a Ham? Broadcast Engineer? Just curious...   Copperfan Posted on Thursday, January 03, 2002 - 10:36 pm:        Hurry Hurry!! i want to upgrade my antenna from the ANT99 lets see the reviews   Marconi Posted on Friday, January 04, 2002 - 9:41 am:        Highlander, I believe that Tech833 is really Hamcber, incognito. I believe he has already told us that he is all of the above. I am glad to see him back. He never has had a very high opinion of the A99 and at one time I felt the same way but I wasn't sure why. Over time and thru many personal experiences I am lead to believe that the A99 is probably the number one contender for the best all-around installation, based on simplicity, performance, price, and effectiveness. Generally speaking, I have a high regard for many of the most popular CB type antennas around. The fully tunable and matchable all metal antennas may have some advantages. They often get some bad reviews because they can be difficult to install properly, but I think there is just not enough difference among them all to really matter as long as they are installed, tuned, and matched correctly. If you really want more performance from you station, then go with a good beam and you should see some significant improvements most of the time. I perfer the flat side with a beam, dipole, or wire. At the very least a good flatside homemade wire dipole that is mounted at least 25' high will give you some improved skip responses in some direction. If you build a simple flatside dipole out of tubing and use a rotator, you may even be more impressed with the skip responses you can get over your typical vertical radiator. If you build one of these dipoles and you see the differences I describe, then ask yourself "what does this say about the gain of an antenna?" Most consider the signal response the most important factor when comparing several antennas. I do not foo-fah signal as unimportant but personally I watch for the signal to noise response as the most important feature I like in an antenna. This can be a significant factor when comparing antennas. However, you must be prepared to have the antennas installed, tuned, and connected to a switch box in order to really realize this characteristic. Marconi   Phineas Posted on Wednesday, April 17, 2002 - 9:08 am:        This Antenna is still a good deal. Especially for the amateur. I can tune every band from 6 meters(50mhz) all the way down to 20 meters(14mhz), and can do most of that with out a tuner. The only thing that is any better for the price IMO is a G5RV for the price. Of course, I never believed the claims of all of the gain...lol   Codeman Posted on Friday, August 22, 2003 - 5:49 pm:        the antron 99 is probally the best thing since sliced bread. i have been running the same one since 1988 with no problems ever!! i sprayed it with clear coat a few years ago but other than that no other mait. at all. i became a licened ham in 1992 and retuned it for 10 meters. it took all 1500 watts my clipperton L could throw at it NO PROBLEM!!!!! perfect swr on 28.500mhz. i have worked the world with this thing. yeah if a op. wanted more gain you could put up a beam but for simplicity pourposes the a-99 or imax is the way to go. if installed properly and i mean PROPERLY the a-99 will give you many years of service. and for that little claim of 9.9db gain the engineer must have been compairing it to a damp noodle HI HI. well 73s and good dx.   Geekster Member Username: Geekster Post Number: 65 Registered: 6-2004 Posted on Tuesday, July 13, 2004 - 10:28 am:        Where are those pics now?   Tech808 Moderator Username: Tech808 Post Number: 2943 Registered: 8-2002 Posted on Tuesday, July 13, 2004 - 11:20 am:        Geekster, The pictures are back now. We sent them out for cleaning and they are nice and clean and bright now! ENJOY. Lon Tech808   Beeker7104 Junior Member Username: Beeker7104 Post Number: 11 Registered: 12-2004 Posted on Friday, October 07, 2005 - 2:37 am:        I have the Solarcon version of the A-99, and to get the most out of mine I removed the top stinger and replaced it with a 102" stainless steel whip. Not only did it improve my receive, it also increased my overall db gain. I have no complaints about the 99, my db gain only improved by 2.2 but it is a noticable 2.2   Lonestarbandit Member Username: Lonestarbandit Post Number: 56 Registered: 10-2006 Posted on Thursday, December 14, 2006 - 11:10 am:        does that 102 idea work??? anyone else wanna cosign on that?   Bruce Senior Member Username: Bruce Post Number: 4232 Registered: 9-2003 Posted on Friday, December 15, 2006 - 4:16 am:        "does that 102 idea work??? anyone else wanna cosign on that?" NO I don't see how it would do anything other that change the frequency that the A-99 is tune to.   Tech808 Moderator Username: Tech808 Post Number: 12509 Registered: 8-2002 Posted on Friday, December 15, 2006 - 8:04 am:        Ask The Tech » Antennas » TOP OF MY I MAX 2000 IS GONE Hope this help's, Lon Tech808 CEF808 N9CEF CVC#2