[450] Mystery QRM

Bob n1ujs at toast.net
Mon May 20 20:32:11 EDT 2013

Thanks Eric.  I appreciate your response.

I am part of a rather extensive group of operators covering multiple states
that have been using 144.450 for a number of years as a gathering
place/base of operations.  Mainly we operate FM horizontally polarized both
base and mobile.  Stations range from hand held pedestrians to full blown
multi-bay arrays.  The context of our operations is mainly perpetuating an
interest in the technical side of the hobby and trying to stimulate more
activity OUTSIDE of repeater operations.  The choice of mode is intentional
as it allows even the most unsophisticated operator to be a part of things,
and the choice of frequency puts us on the weak signal end of the band so
as to be accessible and noticed by the more sophisticated multi-mode
operators.  The idea is to create a non-intimidating environment that will
encourage the advancement of the less sophisticated operators and encourage
the more sophisticated operators to "elmer" the others.  For me personally
it is a forum in which to exercise my perpetually growing station and to
meet my need for intellectual interaction with technically minded folks.
That being said, the other day when the interference started, we were
mainly worried that some packet operator had set up shop 10 khz. down and
we were in for a long bout of difficulties as has been the case in the
past.  However, we had also encountered folks who had inadvertently hit
their "shift" button as well.  It is good to know the interference will not
be long standing.  We are a science minded bunch and most of the guys
wanted me to make it clear that we are fascinated by the Greencube
operations and think it's all pretty cool.  Putting up with it a few times
a year would be no big deal.
None the less, you might suggest to the folks running this stuff that they
put the telemetry on a frequency where people EXPECT telemetry to be, as
the nature of packet operation is NOT to be able to "listen before you
transmit", and is likely to cause interference for many miles from the
height at which the experiment is operating.  We had stations from Vermont
to New Jersey on Sunday morning, and they ALL thought the signal was in
THEIR back yard!

Anyway, thanks for your consideration and perhaps we'll catch you on air
some time.  Maybe our group can someday be of assistance to you folks in
tracking a wayward balloon or something someday!

73 for now, Bob N1UJS

PS- I am CC'ing this response to the 144.450 mailing list.  They wanted to
be sure I didn't intimidate the "cool rocket science dudes"....

On Mon, May 20, 2013 at 7:14 AM, Eric W. Hansen <Eric.W.Hansen at dartmouth.edu
> wrote:

> Hi, Bob,
> From the copied emails you've received, you now know the source of the
> packets you heard yesterday --- a balloon-borne scientific payload over Mt
> Washington, sending GPS info to the ground.
> I became Trustee of W1ET last year and while I was aware that a research
> group in the physics department used ham radio for telemetry (the students
> involved are licensed, by the way), I didn't know their protocol or that
> they were using the club callsign.  In retrospect, it made it easy for you
> to report the problem.  Let me add my apologies for the QRM.
> I will work with the students to modify their research protocol so that
> this doesn't happen again.
> Thanks and 73,
> Eric Hansen KB1VUN
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