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Author Topic: Maxx-com tuner -- is it scam or what?  (Read 5661 times)
DD3LY
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Posts: 25




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« Reply #45 on: January 26, 2005, 12:48:31 AM »

I suppose that the antenna you find at http://www.sommerantennas.com/t25s.html
exactly is the maxx.com but not a balanced version (with a balun) for a dipole, rather an unbalanced version (with an unun). A maxx.com matching-device plus a cheap CB-halfwave antenna and some counterpoise will do this job. Mr. Sommer mentions realistic values of gain you have to estimate with such a structure (I did NOT check these!).
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N5WRX
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Posts: 31




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« Reply #46 on: May 30, 2006, 01:02:30 PM »

I had a Sonny Irons Auto Antenna tuner back in the 80's.
It worked OK but not as well as a 1/4 wave dipole.
It did make a quiet antenna compared to others.

The new Comet CHA250B is basicly the same deal.
A 50 ohm shunt with the antenna attached to one end and ground to the other.
If Comet thinnks it is worth $450 then there must be something good about it.

William Lee
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PA1WAN
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Posts: 1




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« Reply #47 on: July 13, 2007, 04:36:29 AM »

Reading the postings here about the Maxx-com tuner it seems that everyone has an opinion about it but no one has actually bought one to find out what it does, i did! Let me explain, i live in Europe (Netherlands) so excuse me for any weird language and misspelled words. I restored a 40yr old army radio truck (Mercedes-Unimog S404) that i use purely for my hobby. Among others there is a GRC-106 transceiver aboard (400W PEP) that i use for RTTY. I started out with putting up dipole antenna's in the field on three 11mtr high masts but i soon found out it just was to much work, if the field trip was just one day i would not get to my radio's at all! Just setting up and breaking down antenna's. In my shack i had a SG230 autotuner that worked very well in the radio-truck also. I just had to erect 1 mast (instead of 3) and run a 100ft single wire from the vehicle to the mast. If i needed to be really quick i could use one of the 3 whips that are always in place on the shelter. The only problem with the SG230 is that it is only 80 Watts on RTTY (200PEP) and the GRC106 will easily put out 200W. So i went looking for another solution. It had to be an autotuner, lots of other stuff to do in the shelter and i need both hands to tune the amplifier of the GRC106. I looked at the bigger SG autotuners but i found them a bit pricy... Also looked at surplus tuners like the Harris RF-601A but they are hard to find and sometimes very expensive. Then i stumbled on the Maxx-com tuner, at first it looked to good to be true (and then ususally it is), but if it worked it would be the perfect solution. The Maxx-com is obviously not a "tuner" in the normal sense. It needs the radiators to be non-resonant so it is most likely an impedance transformer plus a means to flatten the SWR at the transceiver side. A Coupler would be a better description. Clearly this setup can work, ICOM sells one too and i am sure if you look hard you will find more examples, so there is no need to discuss the principle, it will work, also there is no physical law that claims radiators have to be resonant to be an efficient radiator (look at this excellent piece: http://www.vk1od.net/iobr/)
What i liked about the Maxx-com is that somehow they found a way to let it handle 1Kw PEP wich is a lot more than the ICOM model. I decided to order one and see for myself. Maxx-com claims the tuner to be 80% efficient, i figured that if it can do that, it would be OK by me, 100% power in, 80% radiated power out and no tuning hussle: GREAT!

At my QTH i have a 200ft dipole with a Diamond BU-50 balun and 100ft of Aircell-7 cable to a manual tuner. This is a common setup for hams like me that have trouble routing a balanced feedline into the shack. Before installing the Maxx-com i took FS measurements at carefully defined places (FS can vary hugely in the antenna's near-field at different places) and at several frequencies including the F.res of the dipole. After hoisting the Maxx-com up into the middle mast i retook the measurements at the exact same frequency and places. The results were stunning: at the F.res + 250kHz (Maxx-com instructions ask you to avoid resonance so i added 250kHz) the FS was just a tiny bit lower, my best estimation would be between 5 and 10% down on the old situation. On all other frequencies however the FS with the Maxx-com in place was way up! This can easily be explained, with the tuner at the transceiver i had a widely varying SWR on the feedline that causes great losses in the feedline. The Maxx-com is always under 1:1,5 so feedline losses are down to a minium. After that came the real test, i started working stations in CW in the middle of the day on 40m and got fine results from Poland, Italy, France etc. In the evening i reduced power to 20W and had no trouble working the other stations in the Dutch Amuture net on 80m.

Some time ago i also aquired a new surplus transmitter, a Telefunken S2525/3 (weight: 260kg!) with an output of 1KW. Way more than my tuner could handle so i ordered the new MFJ998 autotuner that will be available to Europe somewhere in the end of 2007. But, after only one week working with the Maxx-com i totally dreaded the idea of going back to the tuner hussle, The MFJ, beeing an "autotuner" will still need a few watts to tune wich means that i must reduce power at the Telefunken, tune, switch to high power, etc. Noting wrong with that and i am sure the MFJ is a fine tuner but by that time i was already used to working with the MAxx-com: just dial a frequency and hit the key! End of story: I cancelled the order and got myself a second Maxx-com for the shack.

Now there will always be postings of people that have never even seen a Maxx-com for real calling it a "resistor in a box", i cannot help that, but saying the Maxx-com is a dummy is like calling me a dummy, you wouldn't want that would you!

Regards,
Willem PA1WAN
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K4KYV
Member

Posts: 41




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« Reply #48 on: July 31, 2009, 07:44:46 AM »

The original MaxCom was developed by a company in Florida, run by a dude named Sonny Irons. Check out some of the 1980's era ads in 73 and CQ magazine.  The photos of Irons in the ads will speak for themselves.

It seems that Irons had a run-in with the law back in the mid 90's.  The following stories tell enough about Sonny to make it easy to understand why he feels compelled to pack heat.

http://www.browardpalmbeach.com/1998-04-23/news/sonny-s-last-stand/1

http://www.waterfront-news.us/98/06/html/speakeasy.htm
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AA4PB
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Posts: 12892




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« Reply #49 on: July 31, 2009, 09:18:03 AM »

Basically its a resistor in a box. The resistor disipates some of the power as heat in order to keep the SWR within reason. How much gets converted to heat vs. how much gets radiated depends on the frequency and the exact length of the antenna wires. The higher the feed impedance of the antenna, the more power gets changed to heat.
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K4KYV
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Posts: 41




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« Reply #50 on: July 31, 2009, 10:20:58 AM »

If you think the MaxCom Automatic Antenna Matcher story was a riot, check out "The Seafarer’s Church of the Creator":

http://www.religionnewsblog.com/13286/estate-owner-wants-to-avoid-33000-tax-bill-by-making-home-a-church
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WR8Y
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Posts: 55


WWW

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« Reply #51 on: July 31, 2009, 10:46:09 AM »

Boy, this guy IS a creep!
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WR8Y
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« Reply #52 on: July 31, 2009, 10:48:59 AM »

"""Basically its a resistor in a box. """

BASICALLY?   You are being too kind - it IS a resister in a box.   It is NOT a 'tuner'.
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AA4PB
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Posts: 12892




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« Reply #53 on: July 31, 2009, 01:00:01 PM »

I say "basically" because I have read that later version have added a toroid transformer of some type. That still doesn't make it an "antenna tuner" as advertised.
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SWL377
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« Reply #54 on: August 03, 2009, 03:28:35 AM »

15,000 people who overpaid for a simple passive device that performs no better than a lossy 52 ohm resistor does not prove anything but gullibility. The fact that the govt and military have purchased a few proves nothing other than technical gullibility isn't exclusively a civilian problem.

It "works", exactly as previously described. It is hyped up to appeal to people wanting and expecting antenna miracles. Brilliant marketing, I do admit that much. PT Barnum had something to say about that.

If the mfr wants to sue me for slander I will cheerfully accept a summons. I would welcome a courtroom battle. My address is in qrz.com.

73,
AF6IM
BSEE, skeptic and RF myth buster
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AC4RD
Member

Posts: 1235




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« Reply #55 on: August 03, 2009, 05:22:50 AM »

After seeing this thread, I went to the ARRL website and found the 1984 review--the one that found the device to be essentially a few resistors and a toroid.

I see the guy from Maxx-com claims the ARRL retracted the review.  But that is NOT on the ARRL review website.  If that's true, Maxx-com, how about posting a scan of this supposed 'retraction' so we can read it for ourselves?
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K8NDS
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Posts: 7




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« Reply #56 on: August 03, 2009, 06:44:23 PM »

I have posted info on this gadget back several years ago; it amazes me that there are actually people out there buying this stuff. What amazes me more is that there are unscrupulous companies selling this stuff. This is what the country has come down to, scamming the unsuspecting and uneducated public. I have made contacts with my dummy load in the past, if you attach a piece of wire to a tee connector on your dummy load you will be surprised what you can work if conditions are right. It's all about leakage, most of the power goes into the dummy load presenting enough of a load to the TX so that the TX doesn’t completely shut down and some minute amount of power gets transmitted from the wire. It's a no brainer!
Oh yes, and by adding some sort of transformer it might make it easier to load the leakage wire. Snake Oil in an Antenna can! I presented an offer to Maxx-Com back a few years ago, I asked them to send me one to evaluate and if it had any teeth to it, I would give it my recomendation. By the way, I did antenna design for microwave antennas as part of my career.
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WA8FOZ
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Posts: 192




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« Reply #57 on: August 03, 2009, 08:21:12 PM »

The thread that would not die!

Amazing what you can do with QRP when conditions permit.
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KI4AUP
Member

Posts: 1




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« Reply #58 on: September 07, 2009, 06:05:01 PM »

If it works then we should be good
Ever wonder why the military is using it?
-It works
-Small chance of breaking down in the field unlike active tuners
-It will work whatever length on the antenna is - if your antenna gets hit by enemy fire you can still operate your radio
-No need for a super efficient antenna just crank the TX power and you're good
-Its broad band. They can inadvertently swap antennas but it will still work.

But somehow their web address www.maxx-com.com doesnt exist anymore. Hmmmmm.

73,

John
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AA4PB
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Posts: 12892




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« Reply #59 on: September 07, 2009, 06:21:41 PM »

No problem at all with the technique - there are times when it can be useful. The problem is when you lie about it and tell people it is some type of very fast "automatic tuner" and try to hide the fact that it is a simple resistive load. It's when you try to hide what it really is so that you can trick people into paying big bucks for it that it becomes a scam.
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