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Re: FO-29



KF4FDJ (Mike in Fort Myers, FL) wrote:
 
> Bill, Brook, et al:
> 
> Brook's scenario, is very possible.

Yes

> I have been in QSO with other ops at times recently and all of a
> sudden, right on top of us someone began calling CQ in CW.

This would be an example of unintentional interference.

> As far as I know, nobody in our roundtable would deliberately
> change to FM mode and intentionally QRM you.

Thats true, because they are a great group of operators.

> First off, how much of the FM signal would you hear with the
> tight filtering I suspect you would use on CW?  If the QRM was
> intentional, a "smart" op would crank up  the power and send a
> continuous carrier to assault your hearing.  Using an FM signal to
> buffet a transponder squatter would be analogous to fighting off a
> mugger with a feather duster.

I have spent a considerable amount of time tracking interference 
sources both commercially and for the amateur community.  When 
tracking the source of intentional interference in amateur systems
it is very important to develope a "personality profile" of the 
suspected offender.  I know for fact that there is at least one 
individual who causes interference on the the mode J and B birds.
I know who this person is, however I can't catch him from this 
location.  The profile for this individual would include being
very intellegent, single, drug abuser and experienced satellite
operator.  I have identified this person causing interference on
terrestrial systems where "low level" FM signals were used to 
irritate and annoy operators on local repeaters.  So you see this
"intellegent" individual can cause interference that will irritate
another operator while at the same time "appear" not to be intentional
interference.
 
> Instead, consider this scenario:
> 
> We have been hearing a great deal of QRM from what appears to be
> FM repeater users in Central America.

I have been following the thread about the repeater in Honduras.  I 
find it some what disturbing how some of our members have been
reacting to this as a possible source of interference.  Personaly I
feel that we should volunteer help to the organization that operates
that repeater and help provide a solution; even equipment if needed.
I think we can accomplish more with love than with hundreds of emails
of complaint.  God knows that part of the world has seen enough
trouble this year.
 
> I have myself flipped my receiver to FM in an attempt to ID the
> offending signal.  If I then forgot to switch the transceiver
> back into SSB mode, and transmitted, the result would be an
> unintentional source of QRM from my FM signal.  Maybe if that
> is what happened, and the op heard distortion in his downlink,
> they moved in the pass band and found a loud signal, (you?)
> and tried transmitting again.  Hence, you would determine the
> FM signal was chasing you.  You must have flipped to FM mode
> from your narrow linear mode in order to determine it was an
> FM signal.  Did you get a call sign (Mike's hoping he doesn't
> say kf4fdj :-) ),  and how long did the signal persist?  Were
> they calling CQ, or was it a whistler, or moaner? (you've all
> done/heard that!)

Mike, when I spoke with you on AO-27 today you mentioned that your
system automatically switches both transmit and receive modes
because you are using the Station Program.  The fact that you 
have figured out this scenario indicates that you are a concerned
and conscientious operator.  Therefore its not likley you would
have been an offender.  Due to the relativley low number of
operators we hear on the FO birds, I think the number of operators
with an identicle operating system as you, would be somewhat rare.
With that in mind, the scenario you describe is also likley to
be rare, but possible.

> My experience leads me to defend the satellite ops as the most
> courteous, helpful, and motivated of the amateur lot.  I don't
> want to believe that ANY regular op would intentionally QRM anybody
> else.  I have a gut feeling that while the QRM was real, there is a
> rational and scientific explanation, and the QRM was caused by an
> unaware op.

I agree with you, however I beleive it is unrealistic to think that
every amateur satellite operator is a picture of mental health based
soley by the label of amateur satellite operator.  Not all of us are
rational, as is evidenced by some of the postings I'm sure you have
read on this BB.
  
> Just some food for though.  Happy new year, and good DX!   73, Mike
> kf4fdj@amsat.org

Yet another dish of thought food from N8OCX, 73


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