[CQ-Contest] K3NM/K5PGW Interference Complaint

Pete Smith n4zr at contesting.com
Tue Nov 27 20:01:19 EST 2001

In the excitement of the contest weekend, most people seem to have
overlooked the latest ARRL Letter, which announces the FCC decision to let
a Warning Notice remain in K3NM's FCC record, substantiating a complaint of
deliberate interference filed by K5PGW. 

The FCC acted quickly to reach a conclusion in this case, and the ARRL
promptly informed the amateur community of the outcome.  In this respect,
they effectively addressed my initial concern, which had to do with
publication of Warning Notices before the fact-finding process is completed.

The decision in the matter states that both sides' positions were carefully
weighed, but it does not discuss the details of the interference that was
alleged, or the time frame involved.  Perhaps this is because K3NM did not
dispute those facts, but it would be interesting and potentially important
to know them, to clarify the precedent that seems to have been established.  

Frequency, time and signal strength factors may be involved.  Amateur HF
communications are not channelized, of course, so interference can occur
even though the stations involved are on quite different frequencies.  In
some lengthy QSOs, particularly on the lower-frequency phone bands, long
pauses can and do occur when neither station is transmitting, and it may be
that neither station is listening ("Joe, I've got to answer the doorbell --
why don't you get your cup of coffee and I'll be back in a minute.") Such
pauses may be long enough for a contesting station to become established on
a frequency and have several QSOs before the rag chewers return and
register their initial interference complaint.  For that matter, if a QSO
goes on long enough, or at a critical time of day, propagation changes can
cause two stations that were coexisting happily on the same frequency to
begin interfering with each other, through no fault of either party.

There is also the issue of different technical standards and thresholds of
tolerance for interference.  We all know how rare it is to have a phone QSO
on the HF bands these days without some degree of interference, usually
unintended.  How much interference is too much?  How much protection does
"good Amateur practice" require an amateur station, using SSB through
narrow multi pole crystal filters, with digital signal processing, to give
another station using an HQ-120 receiver and attempting to conduct "hi-fi"
AM communications requiring a bandwidth of as much as 12-15 kHz?  And
finally, stations coexist in the ham bands with effective radiated power
levels ranging from a watt or two to tens of thousands, dramatically
affecting how much interference is too much in any given case.  

My operating assumption is that Mr. Hollingsworth considered all of these
factors, and that he satisfied himself that K3NM and the station's operator
should have taken action to correct the interference.  But ultimately, we
do not know the facts of the case.  I don't know a phone contester who has
not been harried up and down the 75-meter phone band by self-appointed
"interference cops" who take apparent pleasure in profanely admonishing (in
fact, QRMing) any station that approaches within ten KHz of "their"
frequency.   My concern now is that anti-contest amateurs may be encouraged
to believe that one need only complain about interference, and a permanent
black mark will be added to the contester's record at the FCC.

Some follow-up clarification would, I believe, be both welcome and warranted. 


73, Pete N4ZR

CQ-Contest on WWW: http://lists.contesting.com/_cq-contest/
Administrative requests: cq-contest-REQUEST at contesting.com

More information about the CQ-Contest mailing list