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ZL3AI > APRDIG 18.05.04 21:20l 269 Lines 11015 Bytes #999 (0) @ WW
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: Attn: Armchair Lawyers
From: Steve Dimse <k4hg@tapr.org>
Date: Mon, 3 May 2004 07:48:57 -0400
X-Message-Number: 5
On 5/2/04 at 10:47 PM Jeff King <jeff@aerodata.net> sent:
>Now, I will express my "opinion". I make a good faith effort to see if the
>channel is clear before I transmit. Yes I could interfere with someone, but
>the operative word is "good faith". This is in keeping with the spirit of
>97.101(a). The rules are not absolute, but they are clear about following
>good engineering practices.
Good faith does not appear in the rules. If we can move beyond the legal
argument, which I agree is a decision each person need to make on their
own, all that is left is "97.101 General standards. (a) In all
respects not specifically covered by FCC Rules each amateur station must be
operated in accordance good engineering and good amateur practice."
My opinion is good amateur practice is to do what is practical to limit
interference. I think you would agree that a receive antenna hundreds of
feet higher than my tranmit antenna would do a great deal to decrease the
amount of interference a tranmitter causes on 144.39. My argument for not
doing this is that "my hardware does not support this function"...I don't
have a tall tower at my house, nor can I split the T/R antenna on my radio.
I could build a tower and T/R relay, but it would take money and time and
make my operation more awkward. That I don't do everything possible to
prevent interference does not mean I violate good engineering or amateur
practice.
The argument for deaf transmitting is the same...the hardware does not
support listening. Yes, the user could buy a different tracker, but it
would be bulkier, more expensive, and use more power (and not smell as good
;-).
Of course, listening-before-transmitting is not the only way to prevent
interference...one can run low power, use low antennas, slotted
transmission, low transmit rates, and so on.
I think most people would agree that a deaf tranmitter running 1 KW on a
gain antenna on the top of a mountain beaconing every 15 seconds is not
good amateur practice. However, I maintain a pocket tracker running 300 mw
to a modest antenna beaconing a position report every 5 minutes using
time-slotting is good amateur practice, in fact much better amateur
practice than a lot of what happens now on 144.39. Do you disagree?
Where one draws the line between the two will vary between different
locations and times, there is not one answer that fits all situations, but
I say it is wrong to dismiss all deaf transmitting as bad engineering or
amateur practice.
Steve K4HG
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Subject: Re: Attn: Armchair Lawyers
From: "Spider" <spider@rivcom.net>
Date: Mon, 3 May 2004 05:36:55 -0700
X-Message-Number: 6
From: "Bill Vodall - WA7NWP" <wa7nwp@jnos.org>
To: "TAPR APRS Special Interest Group" <aprssig@lists.tapr.org>
Sent: Sunday, May 02, 2004 7:45 PM
Subject: [aprssig] Re: Attn: Armchair Lawyers
>It's not impossible at all. It's about 99% possible with a digital repeater
instead
>of a much easier to construct digipeater...
>
>Which is better engineering and frequency utilization? A 300 mw transmitter
that
>doesn't listen and covers a few miles or a 50 watt mobile talking to a
mountaintop
>digipeater covering hundreds of square miles and causing hidden transmitter
>collisions to hundreds of stations?
Hi Bill,
What does one have to do with the other? Nothing. Neither should be
acceptable. It's a weird analogy to think if the 300 mw transmitters that
don't listen are not there then there would be 50 watt mobiles talking to
mountain tops. Make no since at all. It's like comparing apples to
fruitcake.
Jim, WA6OFT
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Subject: Re: On digipeater naming conventions
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Mon, 03 May 2004 09:19:41 -0400
X-Message-Number: 7
Agree completely!. If we want to give a digi a geographical name then use
the Amateur Radio Standard Maidenhead Grid! Its even built into most GPS
units. Bob
>>>"Sadowski, Allan" <allan.sadowski@ncshp.org> 5/2/04 9:53:06 AM >>>
Appears this issue has raised it's head again... those who have been
around APRS and packet for a long period of time.. have seen this
before.
For some reason... the US hams keep thinking of US unique approaches... one
of the big issues with ROSE was the area code issue... N America is only
place three digit area codes make sense... not the rest of the world. (from
someone who was trying to get ROSE running in another part of the
world)....
CILLI suffers from the same problems...
Airport designators are more universal... but I know places (some islands
in the Caribbean) that have one airport... but would need multiple digi's
to provide coverage... so that's not workable...
Maidenhead again comes through in this instance...
SO... area codes... are not universal, CILLI is not universal, airport is
not universal ... but maidenhead is... AND... it gives an approximate
location...
If there was a 6x6 maidenhead location that have multiple digis...then the
callsigns are different... and that still makes it unique... and
universal...
Let's think BIG PICTURE... more than just N. America / USA...
my 2 cents...
ALOHA
AH6LS
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Subject: Re: Attn: Armchair Lawyers
From: Steve Dimse <k4hg@tapr.org>
Date: Mon, 3 May 2004 09:21:41 -0400
X-Message-Number: 8
On 5/3/04 at 5:36 AM Spider <spider@rivcom.net> sent:
>What does one have to do with the other?
Actually, Bill's comments make quite a bit of sense. Interference from
"hidden transmitters" is built into APRS, and a lightweight transmitter
regradless of its methods (or lack thereof) for collision avoidance will
often cause less interference than a 50 watt mobile with a receiver with
multiple methods of collision avoidance.
Your post which started this thread expressed a desire to hear "real
opinions" on whether "transmitting before listening an acceptable practice
for this product and products to come on APRS", and yet you are arguing
against people that express those opinions. The fact is that some
influential people feel this can be acceptible practice depending on
specific circumstances, others disagree, and most people just don't care.
This is exactly like most things discussed here on the SIG, and like most
of these disagreements, this is not going to be settled definitively. It
remains up to the individual to decide what to do, but a blanket
prohibition against these devices is not going to happen.
Steve K4HG
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Subject: Re: Attn: Armchair Lawyers
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Mon, 03 May 2004 09:33:44 -0400
X-Message-Number: 9
Rules, rules, rules..
Like anything else, it depends. ANd it depends on altitude proximity and
common sense. And some people seem to lack at least one of the above.
PCsat (and all followon APRS satellites are perfect examples where it is
impossbile to hear anyone else.
Hence, we state a guideline, that says. users may transmit at 5W more
often than 50W stations.
So if someone lacking common sense about his area, his altitude and his
network needs a rule, I would suggest that...
QUOTE: Trackers of 5W or less on moving vehicles NOT AT ALTITUDE may use
receiverless transmission algorithms that are of a low enough rate to
adequately share the channel.
Note: Such trackers only reduce their own effectiveness since the most
likely collision they will experinece is with the local digii which will
thus not be impacted at all, but then will also not hear them. UNQUOTE
Would that be something people could sign up to so that we dont have to
re-hash this once every 15 months?
Bob, WB4APR
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Subject: FW: Re: Attn: Armchair Lawyers
From: "Daron J. Wilson" <daron@wilson.org>
Date: Mon, 3 May 2004 06:41:24 -0700
X-Message-Number: 10
>>Sounds like you have made a legal interpretation on this matter,
>>although I would not agree with it. I could be operating with a manual
>>beacon button, and monitoring the channel.
>
>I started this thread to get opinions. Yes, you could be operating with a
>manual beacon button, and monitoring the
>channel, but that was not what was asked. And, that resolves the legal
>aspect all together. Realistically, how many people do you think are going
>to really do that? You would be kidding yourself and others if you think
>that is going to happen.
Well that is almost completely out of context, you missed it. My point
was that having the carrier sense input disconnected could not be a
definitive indication that I was not making an effort to avoid
interference. I didn't recommend it, I didn't say 'realistically' that
people were doing it. I simply pointed out the fact that using the
status of the carrier sense input wire to determine guilt or innocence
was invalid, making 'effort' tough to measure or prove unless you to go
every transmitter and check its operation.
> Or I could have a tiny
>>tracker with the receiver audio connected but the squelch turned up so
>>the thing transmits anyway? Anyway it is really not worth debating,
>>there are many possibilities and many interpretations, and yours seems
>>narrow.
>
>And your seems un-reasonible. You can 'what-if' any issue all day long and
>prove nothing.
Thanks for making my point for me. The fact that we CAN what-if the
issue means there is more than one possible scenario, which was my
point. The previous post made it sound very black and white: If you
had the carrier sense pin hooked up, you were 'making an effort', if you
did not have it hooked up you were NOT making an effort. It simply
isn't that black and white, and that is not a valid measure of one's
'effort'.
>>>Measurable and able to be easily verified.
>>>Now, how well it works in practice certainly is debatable, but what is
>>not
>>>debatable here is an effort being made. It is a measurable
>>
>>I'm sure no attorney, but I seriously doubt one wins many cases on the
>>premise that his client 'made an effort'.
>
>You really should take some time and review the FCC archives on cases they
>have investigated. You will find,
>that if they prove, to themselves, a reasonible effort has been made(for
>whatever they are investigaging...like 'willfull' interference) they
>normally stop going forward.
I guess the real question here is does operation without carrier sense
violate the specifications for the network we are operating on? If the
APRS spec requires the use of CSMA technology then operating without
using that technology could very easily be considered willful
interference.
73 Daron
N7HQR
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