Hello everyone

Like Mike, I also have the MFJ-1800. And boy was I surprised when none of
my shack full of type N to SMA adapters didn't work. I can't believe they
reversed the polarity of the center pins for WIFI SMA connectors. Urrrrgh
!!!

The FCC requires that Part 15 WiFi devices, having detachable
antennas, *must* use connectors which are not the common, generic,
off-the-shelf standard types.

This was done in order to (try to) (help) enforce the rule that Part
15 radios, and their antennas, must be certificated as a complete
system (radio + antenna), by the manufacturer or by an organization
which does the installation.

Manufacturers of such devices can perform the testing certification
with several different types of antennas, and using such antennas with
that particular device is legal (since they've been certificated as a
system).

Plugging an arbitrarily-chosen antenna into a WiFi radio (access point
or client) will void the Part 15 certification of the device, and it
becomes technically illegal to operate it. That's why a whole bunch
of nonstandard (reverse-polarity, reverse-thread, or otherwise altered
and perverted) connectors are used... the manufacturers are *trying*
to deter people from "one from column A, one from column B"
interplugging, because that's what the FCC has instructed them to do.

The rule gets about as much respect as laws against jaywalking,
littering, or cussing in South Pasadena during the first week of
March, but it's on the books ne'ertheless.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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