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ZL3AI > APRDIG 18.05.04 20:12l 234 Lines 9551 Bytes #999 (0) @ WW
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Fw: Attn: Armchair Lawyers
From: "Doug Younker" <dougy@ruraltel.net>
Date: Sun, 2 May 2004 14:27:30 -0500
X-Message-Number: 11
Interesting because, "acceptable practice" and "legal" are, two separate and
distinct items. In the amateur radio community there practices that are
legal and not acceptable by some, as well as practices thought acceptable by
some, but not neccessarly legal. Jim I wished you would have stated what
rules you believe are being violated since I'm having a hard time recalling
which ones you are referring to off the top of my head and my print and
electronic copies of part 97 aren't available at the moment.
If something is legal depends on Part 97 and I don't have enough information
on hand to comment much on that at this time. I assume the concern is
interference and, I suppose transmitting before listening could be
interpreted as willful interference, but, is it malicious interference? In
the event an action is deemed legal it's acceptability will vary according
to mode of communication. Clearly transmitting before listening generally
will disrupt two way communications as CW, RTTY and Telephony. Packet and
other digital modes can tolerate some interference of this sort and still be
functional. Yes it's conceivable that two or more stations will attempt to
broadcast at the same instant, but does that matter if the network still
works? In the event that transmitting before listening is deemed legal and
if it's proven not to disrupt communications it will become acceptable, but
not by everyone.--73
Doug, N0LKK
dougy@ruraltel.net
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Subject: Re: Attn: Armchair Lawyers
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Mon, 03 May 2004 10:02:40 -0400
X-Message-Number: 12
>>>Jeff King <jeff@aerodata.net> 5/2/04 9:09:46 PM >>>
>Instead of depending on the APRS-SIG for legal advice(!?!), folks would be
>better served by directing there questions here:
>
>http://www.arrl.org/FandES/field/regulations/index.html
>
>Now, even the ARRL can be wrong, but with an opinion from them, you have a
>defensible position with the FCC. You DON'T with the wive's tails being
>floated on the APRSSIG.
Wow, about the worst thing to do is to ask the ARRL for a legal opinion on
something they have demonstrated in the past that they don't udnerstand.
Remember back when they tried to declare all of APRS illegal as one way
transmissions?
Totally blind to the concept of a distributed network.
Asking for a legal opinion from some missinformed lawyers solves absolutely
nothing but only raises the level of dissinformation...
Is common sense totally lost today?
Given:
1) A digi hears say 50 times more than any trackers
2) Any signal that arrives at the digi that is 10 dB stronger than any
other signal will capture the digi and will not be impacted by the
weaker signal. There are 10 to 1 as many 50 watt stations than
trackers...
3) A mobile tracker spends say 1% of its mobile time CLOSE to the digi
(thats 10 times closer than everyone else).
Multiply these probaabilities to gether and you get 2% times 10% times 1%
or a factor of 0.00002 chance that listening first will prevent a
collision. Thats one chance (on average) out of 50,000 packets. Hardly
worth even thinking about...
Sheesh...
But again, its COMMON SENSE. Running a 50W DEAF tracker by someone that
lives a mile from the digi is IN DIRECT VILOATION of the principles of best
practice. Thus there is no rule other than "common sense and best amateur
practice" that can be applied fairly everywhere...
Bob
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Subject: Re: Attn: Armchair Lawyers
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Mon, 03 May 2004 10:07:14 -0400
X-Message-Number: 13
Wow!
Anyone who believes that "legal professionals" are the only one's who know
what's right and what's wrong must really be on another planet. There is
nothing in our legal system and litigious society that EVER guarantees
RIGHT or WRONG. Only who's lawyer is better.
Putting common sense in the hands of legal professionals is like asking....
well never mind. What a waste of time... Bob
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Subject: RE: DAMA was mentioned here !
From: "Scott Miller" <scott@3xf.com>
Date: Mon, 3 May 2004 07:10:51 -0700
X-Message-Number: 14
>OK... enough of my wishful thinking about 20+ year old technology
>actually making inroads to Ham radio. Scott... can we have DAMA and ALE
>as extensions to OpenTrac ???
OpenTRAC came about because of ideas I had regarding coordinated timeslotted
trackers for SAR use. I still hope to implement that someday. I'm all for
moving more smarts to the digi, so long as trackers are also smart enough to
fall back to unaided standalone operation.
Keep support for dumb trackers, but put it on a separate input channel (or
three). Implement a fixed timeslotting algorithm based on callsign/ssid and
GPS time for those units.
On a practical level, I think the biggest problem with a DAMA scheme is
coordinating multiple masters and dealing with hidden transmitter issues.
And no one's going to move to such a scheme, regardless of how efficient it
is, as long as they have the option of cranking up the beacon rate a little
higher on their transmit-only tracker.
Scott
N1VG
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Subject: Multi-2000
From: Robbie - WA9INF <mwrobertson@comcast.net>
Date: Mon, 03 May 2004 09:12:29 -0500
X-Message-Number: 15
Group,
I am trying to set up this rig, FDK Multi-2000, by Fukuyama, for APRS.
I would ask if anyone has the schematic and would be so kind as to send
me a copy. I have worn out Google. I have a manual of sorts, but not a
schematic...
Contact me off list if you can help me out, and thanks in advance..
Robbie
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Subject: Re: Attn: Armchair Lawyers
From: Michael Mullikin <w8ehh@cfl.rr.com>
Date: Mon, 03 May 2004 11:07:27 -0400
X-Message-Number: 16
I usually just read and keep quiet on these list. But I think you all are
missing the point of the rule.
First Transmitting in the blind CAN be an illegal operation and it is
certainly is not good amateur practice. There is nothing in the rules that
says you MUST hear every station out there. But you need to listen and see
if you hear anything before you transmit. That's what makes a common freq.
so congested. If every packet station always transmitted in the blind can
you imagine what problems we would have. There are enough collisions now
and packets not getting thru. I don't believe that it is good Amateur
practice promote that type of activity.
That my opinion
Mike W8EHH
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Subject: Re: Attn: Armchair Lawyers
From: Steve Dimse <k4hg@tapr.org>
Date: Mon, 3 May 2004 11:21:37 -0400
X-Message-Number: 17
On 5/3/04 at 11:07 AM Michael Mullikin <w8ehh@cfl.rr.com> sent:
>I usually just read and keep quiet on these list. But I think you all are
>missing the point of the rule.
>First Transmitting in the blind CAN be an illegal operation and it is
>certainly is not good amateur practice.
Again, I disagree. As I read the rules, tranmitting blind on a packet
channel is NOT explictly illegal, because interference is expected to
occur, excepting "malicious" interference either all interference is
"intentional" or none is. It MAY be bad amateur practice depending on the
specific situation.
>There is nothing in the rules that
>says you MUST hear every station out there. But you need to listen and see
>if you hear anything before you transmit.
There is NOTHING in the rules that says you must listen before you transmit
either, that is your interpretation of what constitutes good amateur
practice, but your interpretation is not shared by all. My opinion is that
you make a reasonable attempt to limit your interference on a packet
channel. A low powered, modestly antennaed station with a reasonable beacon
rate is doing quite a bit to limit its interference even without listening.
Steve K4HG
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Subject: Re: Attn: Armchair Lawyers
From: "Scott Miller" <scott@opentrac.org>
Date: Mon, 3 May 2004 09:15:25 -0700
X-Message-Number: 18
>Multiply these probaabilities to gether and you get
>2% times 10% times 1% or a factor of 0.00002 chance
>that listening first will prevent a collision. Thats one
>chance (on average) out of 50,000 packets. Hardly
>worth even thinking about...
Hmmm. I suppose I could set up my tracker firmware to keep track of how
often it holds off on transmit because the channel is in use.
But let's say that it's one in five transmissions... not unreasonable for a
channel with 20% loading. You're saying that even though I know the channel
is in use, I can go ahead and transmit because there's only a 1 in 10,000
chance that it's going to cause a packet to not decode at the digi?
As for the FM capture threshold, don't forget about mobile flutter.
According to your own PHGmobile.txt file, it can be anywhere from 6 to 30
dB. You only need to have the conflicting signals close within that
threshold region for a single bit time to render the packet useless.
Scott
N1VG
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