[Lowfer] Non-QRSS range (part 15)

[John Davis]

Just a bit of clarification on a couple of points:
>
>If you are only running 100 Mw than you can look for another 10 Db
>of signal at 1 watt


Only true if one were talking about the same band.  In the case of 100mW at
high MedFER frequencies versus 1W at LowFER, it is also necessary to
consider that the antenna is only half the height at LowFER, in proportion
to wavelength.  So, other things being equal, the efficiency of a 15m LF
antenna will only be a fourth as good as a 3m antenna is at MF.  That cuts
the power advantage to 4dB at best.  (And, of course, most noise at LF is
more than enough stronger to offset that.)

>find a spot and use this as you monitor location ,, then as you improve
>things you will
>be able to note the improvement from this spot. make it a kinda standard.
>
>You would want to be away from your near field signal so the spot should
>be several miles away

Establishing a regular monitoring point with dependable characteristics is
indeed a good idea.  "Several miles" is not a necessity with Part 15-size
antennas, however.  You're well outside the near field and transition zones
at a mile or more.  More critical, really, is to find a spot as free from
power lines, metallic fences, and underground pipes as possible.  These
things will not only affect the accuracy of signal readings, but will make
their repeatability less certain.  When we get into the LF ham era, those
pushing 1W EIRP will need to read signal levels with accuracy.  And
repeatability is also desirable, even now with Part 15, to make sure our
before and after measurements really reflect the changes we make to our
antennas or transmitters.

73
John Davis