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ARRL General Bulletin ARLB008 (2015)

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ARLB008 ARRL Warns Experimental Licensee to Avoid Interference to HF
Ham Activity

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ARRL Bulletin 8  ARLB008
From ARRL Headquarters  
Newington CT  February 17, 2015
To all radio amateurs 

SB QST ARL ARLB008
ARLB008 ARRL Warns Experimental Licensee to Avoid Interference to HF
Ham Activity

The ARRL has asked a Massachusetts company that plans to conduct
experimental transmissions over wide portions of the HF spectrum
either to avoid Amateur Radio allocations or to announce the times
and frequencies of their transmissions in advance. The FCC last fall
granted MITRE Corporation of Bedford, Massachusetts, a 2-year Part 5
Experimental License, WH2XCI, to operate 21 transmitters at 10 fixed
New York and Massachusetts sites. MITRE plans to test wideband HF
communication techniques on a variety of bands between 2.5 MHz and
16 MHz.

"[I]t will not be possible for MITRE to operate these transmitters
within the Amateur Radio Service allocations...without causing
harmful interference to a large number of Amateur Radio operators on
an ongoing basis," ARRL Chief Counsel Chris Imlay, W3KD, said in a
February 12 letter to MITRE.

Imlay said that if MITRE does not agree to avoid ham radio bands or
to announce times and frequencies of transmissions ahead of time, it
will ask the FCC to rescind the company's Experimental License or to
impose a prior notification requirement "in real time for each and
every use of the transmitters authorized at each site."

The WH2XCI Experimental License authorizes maximum bandwidths of 5
kHz, 500 kHz, and 1 MHz at effective radiated power levels of 6 W,
24 W, or 122 W. MITRE has indicated that most bandwidths would be
between 100 and 300 kHz.

"At these power levels with the operating parameters proposed, it
will be impossible to conduct your tests at any time within the
Amateur Radio allocations and, at the same time, avoid harmful
interference," Imlay said. He noted that MITRE already conceded this
point in a technical exhibit submitted to the FCC with respect to
its 1 MHz bandwidth mode.

Imlay said that when interference from MITRE's wide-bandwidth
transmitters "inevitably occurs in the narrow-bandwidth, sensitive
receivers" hams use, amateur licensees will have no way to determine
the source of the interference or know to whom they might complain.
"Thus, your assurance of operation on a 'non-interference basis' is
meaningless under the circumstances, and yet that is both a special
condition of operation" of the WH2XCI license and under FCC Part 5
regulations, Imlay told MITRE.

"It is ARRL's intention to ensure that this experimental
authorization, improvidently granted to the extent that it includes
heavily used Amateur Radio allocations, is not permitted to cause
interference to ongoing Amateur Radio HF communications," Imlay
concluded.

MITRE obtained the Experimental License to investigate high data
rate wideband HF communication systems that exploit polarization
diversity multiple input, multiple output concepts to expand the
bandwidth of the communication channel.
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