ETS-Lindgren 3301B Active Rod & Field Antenna (Archived) User Manual

Page 33

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The Antenna Factor

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10.0 The Antenna Factor

The antenna factor data provided with the unit is simply a ratio of the field

strength presented to the unit to the voltage output from the unit at that field

strength. By adding the antenna factor to a given output, the field strength may

be derived. The antenna factor in the Model 3301B combines several factors.

The first factor is the 6 dB required to normalize the rod to 1 meter. The next is

the measured capacitive loss at the front of the unit of about 4 dB. Then there is

the gain of the amplifier itself, 15 dB. Finally, 6 dB is required to conjugate match

the output to 50 ohm. The antenna factor is the sum of these factors. A typical

result might be:

– 6 dB Rod Normalization

– 4 dB Capacitive Loss

+ 15 dB Preamlifier Gain

– 6 dB 50 ohm Matching Loss

= – 1 dB Gain Over Field Strength or Antenna Factor of 1 dB

Archived 3/18/10

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