[BC] Spectral problems at 420-450 MHz

[towers at mre.com]

There are a number of entities who are examining this issue. So far the
manufacturer has said there are several layers of filtering inside the
units and they're nearly bullet proof.  They're not concerned about RFI
and are not seeking RFI protection from the FCC.

The biggest issue I can see here IS RFI to the equipment caused by close
proximity QRO operation of RPU equipment (as well as other types of
tramsmitters).  I don't care what anyone says, the second a RPU station
(or other TX emission) impacts one of these units and either causes an
active misfire or conversely a malfuction, the whole RFR issue gets thrown
into our faces with absolutely no preceptual recourse. That bell will get
rung loudly and the bus will have left the station in a hurry.

Not to mention the liability (perceived or real) of the licensee should
they get sued for wrongful death because the TX emissions prevented
operation despite the FCC's decision to not protect them.  A good laywer
can get that premption overturned in a heartbeat by injunction....and then
the flood gates open to liability of untold limits and our use of the
bands will go down the toilet faster than a power flush.

OTOH, this is a non-issuse otherwise.  Emission of 2mW at 450Mhz will
yield a noise field to about 20 ft. Not worried about IX to my repeater.

MM

 >     This is one that we all should be looking at. It's sure to impact the
 > Broadcast Auxiliary services at 455-455.99 and could be murder on the
 > ham secondary use of the 420-450 band. While I sympathize with the
 > intent, I wonder if this is the right approach.   With the advent of
 > HDTV and the release of large chunks of spectrum in the upper UHF
 > range, it is possible that there are more useful frequency blocks,
 > especially since that range of Freqs. would require smaller antennas
 > for more efficiency on implanted devices.
 > Warning, it's 26 pages of typical FCC verbosity along with some heavy
 > heart string pulling.  Interesting that the only commenter's were medical.
 >  I guess the rest of us users must have missed the original announcement
 > or was it just me.  Our turn is now..
 >
 > http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-09-20A1.pdf
 >
 > Bill Croghan CPBE WBØKSW