Hello Ron,
I forwarded the apparent discrepancy to the authors of the CAP / AF MARS
web site.
I received an amazingly fast and friendly response which basically says
that section 5.2.2.2 in the Redbook are "General Standards" which only
apply when no other standard applies.
The CAP/MARS standard is specified in section 5.3.1.1.A and specifies to
use PEP transmitting wattage in the equation - thus the 63db for a 100
watt transmitter.
You want to get out a calculator and try 50 watts. You'll find the
equation yields 60db.
Maybe 10 watts will do it? Yes, that yields 53db which is a maybe for
the elecraft K3.
Anyway, my goal was not to bash the K3 in anyway, but to discover if it
meets the NTIA specifications which is a looming problem for MARS/CAP
members. From your response, I conclude the answer is no NTIA
compliance for the K3 at this time. And yes, I know this only affects
only a very small number of potential K3 purchasers.
If you are interested, please find below the nice clarification response
I received from CAP/AF:
-----
Hello Howard,
Paragraph 5.2.2.2 in the Redbook are "General Standards", which
pertains to: "Below 29.7 mHz, the following standard applies when no
other standard applies".
CAP's HF-SSB operations, however, are covered by Paragraph 5.3.1 A.:
"Fixed and mobile Stations"; "HF Single Sideband and Independent
Sideband Equipment (2-29.7 MHz)"; "Transmitter Standards", which states
that the formula for fixed and mobile transmitters unwanted emissions:
f(d) > 250% BW is 40+10log(Px) and for the land mobile service (which
we believe applies to CAP) the formula for unwanted emission: f(d) >
8.75 kHz is 43+10log(pX).
The difference between these two is small, but measurable, and we have
never been able to get the NTIA to clarify what the differences really
mean to us. FWIW, some of CAP's HF authorizations say "Land Mobile",
others do not.
At any rate, the 40+10log(pY) formula contained in 5.2.2.2 clearly does
NOT apply to CAP's operations.
Please feel free to ask questions! It keeps us honest, and sometimes
we learn things..:-)
73 DE Hartley Gardner
Deputy Comm Team leader
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