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ZL3AI > APRDIG 26.07.03 09:18l 248 Lines 9994 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Jul 23, 3/8
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: aprssig digest: July 21, 2003
From: WA8LMF2@aol.com
Date: Wed, 23 Jul 2003 02:42:39 EDT
X-Message-Number: 7
In a message dated 7/22/2003 4:46:51 PM Pacific Daylight Time,
rgilson@adelphia.net writes:
>I need about 100ma at 5 to 6 vdc.
>Isolation would overcome ground loops etc and some thing in the 50 ma range
>input allows 24hr mobile operation. Am I missing any thing like
>interference to low band or my AM car radio??? Tnx
Sounds like exactly what I am doing to power my Tri-M integrated patch
antenna/GPS receiver.
Astrodyne makes a vast variety of small sealed-module DC-DC power
converters with complete isolation between input and output in power rating
ranging from 1/2 watt up to 20 watts or so. They are available with either
single-ended or split +/- output for RS-232 or op-amp applications.
I am currently using one of their units that accepts 9-36 VDC input and
produces a constant 5 VDC output to power my GPS. The GPS's 120mA drain at
5 VDC translates to about 55mA at 12 VDC. This unit is a sealed module 1"
by 2" by about 1/4 inch think. It was intended for PC mounting but I mount
it "dead-bug" style in my devices with a blob of RTV and solder wires to
the pins.
I have 4 more of these devices in my mobile system integrator box that ties
together three radios, my VC-H1 SSTV device, a video character generator, a
live NTSC camera, a sound card interface, a TinyTrak, a Tiger Track and a
distribution system for serial data from from the GPS that provides 4
totally separate opto-isolated outputs that can feed the laptop, the
Kenwood D700 GPS port, the Tiger Trak and the Tiny Track. All with no
common grounds.
Astrodyne sells these devices directly from the factory in single lot
quantities, and will accept credit card orders directly from the public.
More info at:
http://www.astrodyne.com (Home page)
http://www.astrodyne.com/astro/dept_dcdc.asp?dept%5Fid=6
(Start page for DC-DC converters)
Stephen H. Smith wa8lmf (at) aol.com
Home Page: http://wa8lmf.com
Ham Radio/Mobile SSTV page: http://members.aol.com/wa8lmf/ham
APRS Stuff
http://members.aol.com/wa8lmf/aprs
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Subject: Add X-Port to TNC?
From: "Bob D." <n2iph@comcast.net>
Date: Wed, 23 Jul 2003 05:30:28 -0400
X-Message-Number: 8
Anyone know how to or thought of retrofitting an existing TNC with a
Lantronix X-Port? Seems like an easy way to add an Ethernet port to a
serial device. Most TNC boxes have more than enough room to accommodate the
X-Port.
http://www.lantronix.com/products/eds/xport/index.html
Can it be done? If not why.
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Subject: APRS Future
From: "Andrew VK4TEC" <vk4tec@hotmail.com>
Date: Thu, 24 Jul 2003 21:13:42 +1000
X-Message-Number: 9
TNC with wireless lan and usb built in
TH-D7A with GPS built in
Geostationary APRS DIGI
Any other ideas ?
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Subject: Re: Reality check needed re uptimes and a soapbox rant, like it or
not.From: "AE5PL Lists" <HamLists@ametx.com>
Date: Wed, 23 Jul 2003 06:34:19 -0500
X-Message-Number: 10
>-----Original Message-----
>From: Gregg G. Wonderly [mailto:gregg@skymaster.cytetech.com]
>Posted At: Tuesday, July 22, 2003 11:58 PM
>Subject: [aprssig] Re: Reality check needed re uptimes and a
>soapbox rant, like it or not.
>
>Dropping the connection doesn't guarentee anything. If the
>network has become
>partitioned because of connectivity problems, the receiving
>software will
>never, ever receive a TCP close, unless keep alive is enabled.
The receiving software will loose the data stream, timeout, and reconnect
or connect to another server. So yes, dropping the connection does cause
indication to the client of a lost data, regardless of whether the client
receives the TCP close. In fact, the far more common instance is with the
client's dial-up connection getting disconnected and the server never
getting a TCP close causing resources to be used even though the client has
gone away.
>Should there be some kind of formal proposal process then? I
>have not heard
>of any design or review board/group that might be 'in charge'
>of what will
>happen to the future APRS-IS system. What's the best way to
>make this happen?
> A sourceforge project? What about an ARRL sponsored working group?
"All" it takes is somebody, preferably working with an organization
currently in place such as TAPR or the ARRL, to take charge, organize a
working group, and manage the process. I do not have the time to be such a
person, but I would be glad to support such an effort. One of the first
steps would be to develop a document delineating the current APRS-IS system
as a basis for future development as all TCP/IP capable clients are
compatible with that system.
>What I purposed provides a TCP connection to the client that
>is identical to
>what they see today. That is the only 'standard' that has
Except that it does require implementation of a new piece of software on
every client. And certain clients may not be able to support a proxy
server environment (a Java applet is one example that has fixed security
restrictions on types of sockets supported). Restrictions such as these
may not preclude your design, but these type of implementation issues
should be addressed.
>works. Steve's numbers provide an indication of that. So,
>as you ask, is
>there any gain that will be worth the pain?
Sometimes yes, sometimes no. It is up to the proponent of the "gain" to
convince the others that it is worth the "pain". While I feel that your
proposals merit further investigation and definition, I feel that many
questions remain to be answered. But those are my opinions and may not
(probably don't) reflect those of the rest of APRS-IS users. That's why a
coordinated effort towards an APRS-IS V2 is needed.
73,
Pete Loveall AE5PL
pete@ae5pl.net
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Subject: Trucks with 7 and more Wides
From: "Clayon H. Owen" <aa3jy@winlink.org>
Date: Wed, 23 Jul 2003 7:26:36
X-Message-Number: 11
Is having "RELAY,WIDE,WIDE,WIDE4-4" really necessary with the amount of
digis and TCP/IP coverage?? Also having a beacon rate of 30 sec. is that
really necessary..?? If the concensis of this 'List' feels that all of this
is NOT necessary please advise the rest of the Truck community..especially
N3MEP-14 the proper APRS 'PATH' etiquette...
Thanks
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Subject: I-gate question.
From: "Dave Thege" <dthege@conpoint.com>
Date: Wed, 23 Jul 2003 07:48:08 -0500
X-Message-Number: 12
When you gate Internet feed to RF what stops the local Digi from
re-inputting it to RF and back down the line? The local digi is 7 miles from
me.
My concern is that it will hear my output and digi it back down the line.
Does the path get appended when you gate packets from the internet to RF?
Dave N0XBN
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Subject: RE: Trucks with 7 and more Wides
From: "Dakota Summerhawk" <dakotas@dotorg.org>
Date: Wed, 23 Jul 2003 06:50:26 -0600
X-Message-Number: 13
I have my tracker set to relay,wide3-3 and a report rate of 2 min and that
works just fine for accurate tracking. Don't se a reason for the excessive
path or the short report rate.
Dakota
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Subject: Re: Trucks with 7 and more Wides
From: "Gregg G. Wonderly" <gregg@skymaster.cytetech.com>
Date: Wed, 23 Jul 2003 08:53:57 -0500
X-Message-Number: 14
30 sec may be excessive, but it may be that this traveler knows something
about a part of the route that they drive that makes that rate necessary. The
PATH, looks to me, to be an attempt to work around the issue that we have not
been able to convince people to upgrade or properly configure their digi's.
It may also be that there is a problem reaching an igate somewhere and this
path has been proven to work. The irregularity and misconfiguration of the
DIGI infrastructure makes it impossible to always use the optimum path without
having a way to configure it every 10 min based on some historical record of
the past 10 min of propigation and operational capabilities of the network.
-----
gregg@cytetech.com (Cyte Technologies Inc)
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Subject: Re: Trucks with 7 and more Wides
From: Rich Garcia <k4gps@bellsouth.net>
Date: 23 Jul 2003 10:05:28 -0400
X-Message-Number: 15
I am usually set to relay,wide,wide and that works fine here but it may
differ in other areas. For a OTR maybe WIDE4-4 would be fine but since
many areas don't support WIDE-N that would be a poor choice but the path
you mention below is excessive.
As far as timing 30 seconds is excessive with such a path unless it is a
"race car" blasting through the area. If I am doing high speed highway
trips once a minute with a double wide is my choice. It would just
create a mess depending on the number of digi's in the area and if
he/she is in one place for any period of time.
I just got back from the island of Bimini and did raw APRS packets using
MixW since my friend did not have APRS loaded in his PC. Since it was HF
soundcard packet with a 50W radio and a dipole at 6ft with the shield
side laying in the ocean I bumped it up to once a minute, I had also
heard of a solar disturbance. If I had a better signal I would have done
once every 15 or 30 minutes. Packet rates should be set with a bit of
education and knowledge of your probability to get out from your
location.
Rich
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