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R. F. from the exciter / amplifier flows along the coax cable at 50 ohms and then to the MAXX-COM Matcher. Directly connected to the coaxial input connector (SO-239) is an elaborate R. F. transformer. The primary windings present a 50-ohm load at any frequency within the range of the particular MAXX-COM unit. (Commercial units operate from 100 KHz. to 250 MHz. and utility models from 1.5 MHz. to 30 MHz.) To increase current flow across the primary windings and to protect the transformer, should no radiator be present, non-inductive resistors are connected to the termination end of the primary windings. This resistor network is so designed that it also eliminates the resonant frequency spike common to this type of matching unit. Then second and third windings are strategically wound to receive the induced current which is then fed to the reactive outputs. In operation with a sufficient radiator load, very little RF flows into the resistor network. However, with very short radiators or no radiators most of the available R. F. re-circulates through the network. The larger the radiator load presented to the MAXX-COM, the more efficient is the transfer of R. F. energy from input to output. The MAXX-COM Matcher, a grounded, non-resonant device, works best with a non-resonant radiator. For example: A 100 foot dipole is seen resonant by the MAXX-COM device at 4.7 MHz. and at only that frequency +/- 500 KHz. If 4.7 MHz. +/- 500 KHz. is your operating frequency, you should lengthen the radiators enough to eliminate resonance. (The MAXX-COM unit will still match with less than 1.5:1 VSWR, but efficiency is reduced.) For the above stated reason, bench testing for efficiency is impossible for anything except worse case as all dummy loads are resistive. ELECTRO-MAGNETIC FIELD The electro-magnetic field generated by a dipole matched with a MAXX-COM device is somewhat different than with a resonant tuner. A resonant tuner when properly tuned causes the radiators to vibrate from side to side like a string in a piano or guitar, thus creating the R. F. field. The MAXX-COM device, being grounded and non-resonant, forces the R. F. onto a highly reactive radiator. R. F. runs to the end of the wire and with the collapsing field returns to the input where it is blocked and forced to return to the far end again and all within a period of time fixed by the operating frequency. As can be understood, the longer the radiator wire(s) the stronger the electro-magnetic field generated, due to the fact that the R. F. must make the trip from beginning to end in the same fixed amount of time. We recommend a dipole of 100 feet total length or longer for maximum efficiency. PLEASE NOTE: Many installations operate satisfactorily with shorter lengths. COAX LOSSES With a MAXX-COM device in service, gains over a conventional "Pi" or "L" network tuner may be realized in the area of coax feedline losses. Conventional tuners mounted near the exciter / amplifier actually tune the coax and radiators. A MAXX-COM allows the coax feedline to operate in true 50-52 ohms as matching occurs at the radiators. Tests conducted by MAXX-COM demonstrated that 5,200 watts could be fed to a MAXX-COM 2000 D, 100 foot dipole through 200 feet of Saxton 8315 (Mini-8) coax feedline with no measurable heating of the coax at any spot. The same test with a conventional tuner produced multiple hot spots that melted and destroyed the coax. This heating indicates a loss of efficiency often overlooked by radio operators. Whatever heating takes place with a MAXX-COM system is confined to the matching unit itself and can be measured and evaluated. In fact, the MAXX-COM device has been improved by design eleven times using measured heating as an indicator of efficiency. In one comparison test, an imitation MAXX-COM exploded in 41 seconds while the MAXX-COM sustained only 52˚ F. temperature rise in 3 minutes and 15 seconds. (Test results available on request.) MAXX-COM ADVANTAGES The MAXX-COM Automatic Antenna Matcher is offered as a communications antenna system. It was never intended to be a narrow band "DX" antenna. MAXX-COM will allow any operator, from novice to expert, to effortlessly use his / her transceiver over the entire HF band and never have to transmit first before operating on a new frequency. A recent experience aboard a sailing vessel, related to us at MAXX-COM, demonstrated that with today's digital read-out radios and a MAXX-COM Matcher, a solid signal can be transmitted by anyone, under the most dire of circumstances, to bring the needed help. MAXX-COM was conceived, developed, manufactured and guaranteed in America by Americans. The operation of a MAXX-COM involves only the initial installation. From then on you only have to dial your frequency and talk. MAXX-COM can be used with ANY high frequency radio. Never needed are tuners or meters between the radio and the MAXX-COM. MAXX-COM will match any dipole, longwire, whip, backstay or tower. MAXX-COM needs no DC or power supply connection as the coax does the whole job. There is even a model that matches with no RF ground. SEAL THE CONNECTION One problem that repeatedly comes up related to installation is that of properly sealing the SO-239 / PL-259 coax connection. These connectors are not waterproof and as soon as water carries contaminates into the connection, corrosion begins and the connection is no longer 50-ohms. The operator notes proper matching upon transmitting because RF burns through the corrosion, but upon returning to the receive mode, signals are severely muted because receive voltages cannot penetrate the corrosion. Continued operation ultimately will destroy the connection and make the MAXX-COM unit unusable and non-repairable. Please use all ten inches of Coax-Seal we provide with every MAXX-COM to perfectly seal this connection. FUTURE IMPROVEMENTS Presently we are experimenting with permanent magnets and other means to increase efficiency of the MAXX-COM device. Also promising, is the use of special RF diodes to force more RF energy onto the output connectors. We are dedicated to developing MAXX-COM into the most efficient antenna coupler available. Certainly the future is bright for MAXX-COM. You may be interested to know that MAXX-COM is built to be a fully hardened device. We believe the Commercial Model MAXX-COM will pass a one megaton nuclear EMP (electromagnetic pulse) test 5.5 million volts for 1.5 microseconds). That explains why many users of MAXX-COM Matchers have told us about direct and indirect lightning hits that destroyed everything in line except the MAXX-COM. We feel confident in extending a ten-day, money-back trial to everyone and backing up all of our MAXX-COM Models with a five-year guarantee. SIMPLY CONNECT, DIAL YOUR FREQUENCY AND TALK. Sonny Irons, Inventor / Manufacturer | Return Home | About Maxx-Com | Our Models | Internet Special Pricing | Installation Info | Our Customers/ Testimonials | FAQ Page | Contact Us | |
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