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[TenTec] Antenna Tuners for Balanced Antennas

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Subject: [TenTec] Antenna Tuners for Balanced Antennas
From: SEWATKINS@dgs.state.va.us (Sherrill WATKINS)
Date: Mon, 29 Jan 2001 10:37:02 -0500
Jim:  You are correct about installing terminating resistors at the ends 
of rombics, v-beams and long wires.  This is only for the purpose of 
causing the antenna to become directional off the terminated end. 
If the antenna terminating resistor is removed, the antenna will be 
bi-directional, i.e. radiate off both ends.  Terminated rombics and 
v-beams were in common use with the military who desired a fixed, 
point to point antenna to communicate great distances.  However, 
when yagi's became developed and popular in the 1950's, they 
gradually, but not completely, replaced the rombics and v-beams 
because they did not require so much land and they could be rotated.  
For the rombics this type of  resistive termination is discussed in some 
of the older copies of the ARRL antenna book and would require a 
noninductive type resistor. These large rombic antennas were fantastic 
performers and were aperiodic with tremendous bandwidths. Another 
advantage they offered is they could achieve a very low angle of
radiation without extreme height.  They were always fed with 
open wire line.  For amateur use, the major drawbacks are the large 
amount of land they require and they are only single or bi-directional.  
>From what I can remember, they were the type preferred by 
commercial telephone carriers when world wide point-to-point
hf telephone service was developed in the 1920's and '30s.  Based 
on a rough estimate, I would expect any antenna that has a 
resistor inserted in its center or feed point would perform very poorly as 
at least 50% of one's transmitted rf would be dissipated as heat and 
likewise for the received signal.   The Maxon (sp?) tuner was a 
fraud that was perpetrated on unsuspecting amateurs.  Fortunately, 
it was exposed by the ARRL in the QST article that you refer.
- 73's- Corn - k4own. 
 

Corrupt politicians love unarmed serfs.


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