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VLP stands for “Very Low Power”, as defined by me on today’s date. Let me explain why VLP has a place in part 15 research.
Antenna testing.
That’s it.
Why is it useful for antenna testing?
VLP stands for “Very Low Power”, as defined by me on today’s date. Let me explain why VLP has a place in part 15 research.
Antenna testing.
That’s it.
Why is it useful for antenna testing?
Because unlike operation at 100mW into the final and xx% efficiency RF output feeding the antenna, which requires traveling some distance down the street to reach the fringe, with VLP the fringe is a few feet away. The scale of the test field has been reduced to miniature size.
Which transmitter is ready to operate at VLP?
The AMT5000, with it’s power control normally intended to achieve exact 100mW to final. That same output control can be dialed way down so the signal is just barely present. Perfect VLP.
Total posts : 45366I suppose it would be a useful approach in testing antennas in a confined way.
However testing at lower power other than what Part 15 allows, what is the point? All that testing would be useless in applying the results to a 100mW driven system simply because the two are different.
Perhaps Miniature Part 15 setups? 1/100th scale perhaps?
Hmm…perhaps a new market idea here, make and sell miniature models of Part 15 stations. Glue and paint not included. :p
RFB
Total posts : 45366Interesting idea Carl but here are a couple of points to ponder.
Measurements made close (wavelength wise) to the antenna will be in the near field where induced power in the receive antenna dominates. Measurements farther away will be in the far field which is more representative of the case of expected listeners. VLP signals may not be detectable in the far field.
Instruments used for electronic measurements provide more accuracy with larger signals. A general rule is to make measurements in the top third of the instruments’ range. This is because accuracy specs. are a percentage of full scale plus/minus a constant. When operating at the low end of a scale the constant error and percentage of full scale can get large. For example, a DVM has a speced. error of 1% FS plus/minus 1 LSB digit. Measuring 9V on a ten volt scale with 4 digit display, the error is .01X10V +/- .01 = .11 volt which is .11/9 = 1.2%. Measuring 2 volts on the same scale the error is .11/2 = 5.5%.
Except for this the performance of an antenna system should be scalable for power applied.
Neil
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