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Stagger Lee

On 26 Oct 2006 12:52:48 -0700, N9OGL wrote:
:
: wrote:
: N9OGL wrote:
: Omega One Radio is Now on 6.950.00 MHz Lower Side Band with a power
: output of 50 to 100 watts
:
: If this is for real, you are plain nuts.
:
: 6.950 is not an ISM/HiFER allocation in the US. Even a Canda ISM s
: 6.765-6.795.
:
:
: Canadian RSS-210 rules, Section 6.2.2 (e) permit operation in the same
: band but at slightly higher field strength, 15.5 mV/m at 30 m. Their
: frequency stability requirements are similar. Canada also has another
: license-free HF band not available in the USA; 6,765 - 6,795 kHz. Field
: strength and frequency limits are the same as those for 13,553 -13,567
: kHz.
:
: Terry
:
: Accually, there is band allocation in that band in the US is 100
: microvolts per meter @ 3 meters

A second back of the envelope calculation says you are way over the
legal field strength in this case too. As I said before, you can
calculate the power it takes for an isotropic radiator to produce a
field strength of 100E-6 volts/meter at a distance of of three meters
as follows:

1. The area of a sphere of radius r is 4*Pi*r^2. An isotropic
radiator emitting P watts at the center of the sphere will produce a
power density of Pd = P / ( 4*Pi*r^2) on its surface.

2. The power density is related to the electric field and the
impedance of free space (120*Pi) by the formula Pd = e^2 / (120*Pi).

3. Solving (1) and (2) for the power, P, you come up with P = (er)^2 / 30.

So, for an "e" of 100E-6 and an "r" of 3, P = 0.01732 watts, or
roughly seventeen milliwatts.

Since antennas are not isotropic, the power must be reduced even further
so that the electric field will not exceed the legal limit in the
direction of highest antenna gain.

This calculation ignores line losses and final amplifier
inefficiencies, but there's no way you can convince me that you can
take a 50 watt transmitter and manage to lose so much power that you
have seventeen milliwatts or less being radiated.

All my DeVry Correspondence School instincts once again tell me that
you are seriously in violation of the law. Other DeVry grads at the
FCC will probably agree, as will our distinguished but indisposed
alumnus, AB8MQ, the only man to have discovered negative VSWR.

[Note to Woger: V pbcvrq guvf zngrevny sebz Yyblq Qnivrf. Rng lbhe
urneg bhg.]