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ZL3AI  > APRDIG   22.06.04 09:51l 479 Lines 17056 Bytes #999 (0) @ WW
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To  : APRDIG@WW

Subject: APRS-IS vs RF backbones
From: rsnyder@toontown.erial.nj.us (Bob Snyder)
Date: Wed, 16 Jun 2004 12:23:31 -0400
X-Message-Number: 49

On Tue, Jun 15, 2004 at 06:06:47PM -0400, Danny wrote:
>Lets face it, the internet is everywhere. In the event of a disaster, you
>cant be more than a couple hops to an IGATE. Replacing what we already have
>with APRS-IS with our own MUCH SLOWER and LESS RELIABLE backbone system
>doesnt make sense.

The Internet is everywhere. But most providers I know of tend to
aggregate up a region's traffic to a single Point of Presence, and
connect that back using larger pipes to the provider's backbone, to a
regional interconnect point, or both. Often the POP is co-located with a
regional interconnect, since that saves on transit costs. The POPs and
the interconnects are generally hardened with protected transport,
UPS/generators, etc, but hardening against rising flood waters or bomb
damage is challenging.

The net effect is that if something happens in that data center, then
connectivity in and around the region served will be disrupted, likely
over multiple carriers. The Internet as a whole will route around it,
perhaps becoming a bit slower because of lost links, so it'll go on, but
the region will be effectively isolated.

Here in the densely populated Northeast US, you might be 3-4 hops away
from a working Igate from a disaster site. In less populated areas,
where the regions served by an aggregation point are larger, I suspect
the number of hops will increase to find working Igate.

Bob N2KGO

----------------------------------------------------------------------

Subject: Re: Kenwood blah blah blah
From: Dale Blanchard <wa7ixk@arrl.net>
Date: Wed, 16 Jun 2004 10:09:33 -0700
X-Message-Number: 50

I made a spark gap transmitter. Got the plans from my fathers Boy Scout 
book.

----------------------------------------------------------------------

Subject: Re: Re[2]: Re: Trains, planes and APRS automobiles. was: Kenwood APRS
radio
From: "Scott Miller" <scott@opentrac.org>
Date: Wed, 16 Jun 2004 10:27:39 -0700
X-Message-Number: 51

Not much to show yet. The box will probably wind up being a digi
eventually. It's just a Soekris net4501 running Debian Linux. It's
connected to an 85 amp hour deep cycle flooded lead acid battery and a
couple of 5-watt Harbor Freight solar panels. I added the second panel on
Sunday (they went on sale again), but I'm not sure it's enough to maintain a
net charge. It's been up almost 11 days, though.

It wasn't really a planned test... I'd just converted the net4501 to an APP
connector, and it happened to be sitting next to the big battery. My larger
batteries have 50-amp Anderson Multipole connectors, so I grabbed my
1-Multipole-to-3-Powerpole adapter and hooked it up. Then there were a
couple of extra powerpoles hanging off the battery, and the solar panel
sitting there had a powerpole, so I figured, what the heck.

It's all the powerpoles' fault...

Scott
N1VG

----- Original Message ----- 
From: "DG2JW" <dg2jw@privateasylum.com>

Scot.
How about some pictures and comments about your solar powered igate?

Julian

----------------------------------------------------------------------

Subject: Re: PSK31 APRS
From: Jeff King <jeff@aerodata.net>
Date: Wed, 16 Jun 2004 12:48:36 -0500 (CDT)
X-Message-Number: 52


Quoting Scott Miller <scott@opentrac.org>:

>>The long and the short of it is, what is most "pleasing" to the eye is also 
the
>longest, and
>>in PSK31's case, very long. Upper case and numbers are the "longest"
>varicode,

>Yeah, I know. But I understand PropNet has been using it like this, and
>Ithink there's a way to use UI-View32 with it. And it's human-readable,
>of course.

Yeah, I seem to recall that human readability was a certain design
parameter of someone's Amateur AVL system once... strange to see it in a
requirement of yours though.... ;-)

How long (in time) does it take to send a position report?

BTW, don't forget there is plenty of Windows open source for PSK31, and
making a decoder for it would not be that hard. To really do justice to a
(non packet) AVL network on HF, is going to need some semi custom parsers
for the IGATE, for alot more reasons then just a compact protocol. So,
IMHO, I'd certainly test with the existing stuff, but not let the tail lead
the dog. I think development stopped on the UI-View PSK31 server in 2001,
if I am not mistaken, so boat rocking shouldn't approach the lovefest we
saw on here during the OpenTrak balloon flight. In fact, I imagine you
could interface to UI-View the same way the UI-View PSK31 server does... it
is a seperate app. 

>>What kind of IMD numbers are you getting?
....
> Not sure what I need to do to get a real number there.

I know MIXW can display IMD, so maybe DigiPan can also? (same author) This is
something you really need to be looking at, as that was my biggest fear with 
the "4 bit resistor D/A" but of course you are using a 8 bit PWM. Looking at 
your waterfall, it looks fairly clean. Make sure to look at the entire audio 
passband... you can get away with murder on the APRS frequencies but PSK31 
folks won't be so forgiving.

>http://n1vg.net/opentracker/images/psk31-test.gif
> 
>Something with FEC and 8-bit support using BPSK would be kind of cool.
>For
>HF use, a 6-byte, 2.5-meter resolution position report should be more
>than sufficient.

Yeap, same thought, in general, might be said about the APRS-IS, where the 
thought is "you are at a distance" so getting you close is the goal. Then 
again, data mining, it is hard to say. But on HF you have real considerations 
for making the packet as short as possible, due mostly to the very low baud 
rate. Throwing away resolution (and using a compact format) are two ways to 
achive this.

>Something with FEC and 8-bit support using BPSK would be kind of cool.

Here is a test comparing PSK31 to MFSK16:

http://home.teleport.com/~nb6z/compare1.htm

So errors can happen in either mode, which means some sort of CRC/Checksum 
should be appended to the report, even if the existing apps toss it away.

>What's the standard PSK31 preamble, if any? I'm just sending a bunch
>of zeros for now, but it does seem to take a bit to lock on.

Not sure if you mean a logical zero, or the char "0". In the former, then yes, 
you'll have lockup issues as it is a illegal varicode symbol. If your looking 
for suggestions, I'd pick a standard, printable, very short, Varicode synbol. 
Maybe a "e" (two bits) or "o" (three bits). That way, you can reduce the length 
of the preamble to the shortest needed. Also might be useful for defining the 
information type.

http://home.teleport.com/~nb6z/psk31.htm#Information%20Coding

73

-Jeff wb8wka

p.s. Is this PSK31 tracker code going to be part of the OpenTracker product 
line? I'd love to hook it up to my Warbler... already have a 80 meter mobile 
antenna.

p.p.s. I'm on Digital HF, if you want me to give you a over the air IMD, give 
me the time and place, and I'll try and be there.

----------------------------------------------------------------------

Subject: RE: Trains, planes and APRS autom obiles.
From: "Bill Vodall" <wa7nwp@jnos.org>
Date: Wed, 16 Jun 2004 10:55:25 -0700
X-Message-Number: 53

>If you want emergency comms, your REAL options are:
> 
>1. Portable Satellite Terminals

Yes. Good stuff!

>2. HF Radio, running on batteries

Email via Q15X25 or Winlink (http://www.winlink.org )

>3. 2 meters, non-repeated

Why non-repeated? (I assume you mean digipeated - true packet repeaters
actually make packet useful over a large area.) I can Email ala Packet with
N4RVE (see the latest CQ-VHF issue) who's nearly 100 miles north via an
essentailly pure solar power "digipeated" circuit. We're not exchanging
MP3's but it works well for basic communications.

Speaking of emergency preparedness:

1. Do you have a 72 hour kit for both mobile and home?

2. Can you operate your mobile and/or home ham station for 72 hours with no
commercial mains?

3. Will your APRS stations, mobile and/or home, run for 72 hours off the
mains?

4. How about real packet (or HF Winlink) off the mains?

I judge my personal setup by the ability to send and receive Email using
packet on local power. It's a core technology that would be highly useful
given an serious incident.

73,
Bill - WA7NWP

----------------------------------------------------------------------

Subject: Re: Kenwood blah blah blah
From: Jeff King <jeff@aerodata.net>
Date: Wed, 16 Jun 2004 12:56:53 -0500 (CDT)
X-Message-Number: 54

Quoting "J. Lance Cotton" <joe@lightningflash.net>:

>But, can you do MFSK16 via the mic-jack with an 8-bit microcontroller?
>(I'm really asking, I don't know!)

I don't see why not.... in alot of ways MFSK would be easier then PSK31....
the only difference between it Bell202 is the speed and the fact that there
are more then two tones.... just basic phase coherent FSK.

Now... the tricky part is the FEC and interleaving on a microcontroller...
but in a UI mode this buys you a whole bunch. There is a new "mode" called
dominoe that is MFSK, except no FEC:

http://www.qsl.net/zl1bpu/MFSK/domino/

For a amateur radio AVL network, the BIG advantage of domino is its 
insensitively to mistuning (AFC). This is a big deal because for effective 
network, you can't keep tuning in the mobiles. 

The source code for dominio is on the Yahoo site.

----------------------------------------------------------------------

Subject: Re: Kenwood blah blah blah
From: Jeff King <jeff@aerodata.net>
Date: Wed, 16 Jun 2004 13:12:04 -0500 (CDT)
X-Message-Number: 55

Quoting Jeff King <jeff@aerodata.net>:

>Quoting "J. Lance Cotton" <joe@lightningflash.net>:

>>But, can you do MFSK16 via the mic-jack with an 8-bit
>microcontroller?
>>(I'm really asking, I don't know!)

>There is a new "mode" called
>dominoe that is MFSK, except no FEC:
>
>http://www.qsl.net/zl1bpu/MFSK/domino/

Well, look what I just found, seems the domino guys where thinking of APRS
when they designed the mode. (except APRS really isn't ack/nak) From:
http://www.qsl.net/zl1bpu/MFSK/domino/Technical.htm

---------
"An ARQ mode using IFK How about developing an ARQ mode using IFK? This
would allow packet-style operation on HF with much improved frequency error
tolerance. Existing simpler HF packet modes suffer badly with multi-path
reception and Doppler, and some of the more sophisticated types, which fare
better, require very high frequency tolerance, not easily achieved with a
typical mobile installation. Since there is interest in HF mobile telemetry
(specifically APRS), there is scope for an IFK coded ARQ mode to be
designed in order to support this activity. domino is intended to promote
familiarity with the techniques that would be required. Mobile operation
would also use a transmit-only encoder (microcontroller) and so no PC or
sound card. The PC TX/RX software would operate as a sound card driver,
similar to the AVG packet driver.

A 32 tone, 31.25 baud ARQ system based on domino would achieve 125bps in a
1kHz bandwidth, and probably achieve up to 500Hz tuning tolerance. Sync
lockup would be under 0.5 seconds, allowing a typical APRS UI frame to be
transmitted in under 8 seconds. Character (byte) sync uncertainty would be
resolved by performing two CRC calculations spaced one symbol apart at the
receiver. It is not suggested that the design need necessarily support the
full AX25 link layer protocol for connected and BBS operation. "

----------------------------------------------------------------------

Subject: 2 M Heathkit Model HW-30 "The TWOER"
From: "Tom Perry" <kd4ufd@earthlink.net>
Date: Wed, 16 Jun 2004 12:19:40 -0700
X-Message-Number: 56

I had a piece of Ham Radio history drop into my lap while I was on
deployment. I have this beautiful radio well cared for and in GREAT shape.
I want to put it on the bench and test the rig to make sure it is ok before
I power it up. I need Circuit Drawings with values for the components so I
can test this radio. Does anyone know where I can get a copy of this piece
of paper?? Are they online???? or am I going to have to reverse draw what I
see and figure it out on my own?? Any help that can make this process
faster would be great. Have lots of pen's and a multi-meter in hand with
lots of paper at the ready...

73's.....

Tom Perry
kd4ufd@arrl.net

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: Robbie - WA9INF <mwrobertson@comcast.net>
Date: Wed, 16 Jun 2004 14:28:12 -0500
X-Message-Number: 57

Tom,

My biggest crutch since the internet is Google.. There is hardly ever a 
question not answered like yours. Then again, some one just may be using 
one here since APRS has revived a lot of old equipment sitting and not 
being used.. hi

Any way, I would try Google also

Robbie

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: "Tom Perry" <kd4ufd@earthlink.net>
Date: Wed, 16 Jun 2004 12:33:14 -0700
X-Message-Number: 58

Rgr, Robbie,
 Tried there first, Guess I needed to tailor my search better. I only
got sites that sold part.... no drawings....

Tom Perry

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: "DG2JW" <dg2jw@privateasylum.com>
Date: Wed, 16 Jun 2004 22:37:05 +0300
X-Message-Number: 59

check out this site Tom.
if you don't mind paying try the first link.
www. surplussales.com/Manuals/man_heath.html remove the space from the link.

Or you can check if these are what you are looking for from my server.

privateasylum.com/heathkit_hw-30/

I hope this helps you :)

Ham spirit alive and well in Finland

Julian
OH8GEJ

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: "Tom Perry" <kd4ufd@earthlink.net>
Date: Wed, 16 Jun 2004 12:42:10 -0700
X-Message-Number: 60

rigor will do. I have a drawing for a daughter board that is FM that I
think I can add to this radio (and a switch as well).

Tom Perry
kd4ufd@kd4ufd.com
http://www.kd4ufd.com/

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: Danny <danny@messano.net>
Date: Wed, 16 Jun 2004 15:44:51 -0400
X-Message-Number: 61

ftp://bama.sbc.edu/downloads/heath/hw-30/

----------------------------------------------------------------------

Subject: Re: 2 M Heathkit Model HW-30 "The TWOER"
From: "Tom Perry" <kd4ufd@earthlink.net>
Date: Wed, 16 Jun 2004 13:04:26 -0700
X-Message-Number: 62

Thanks Danny ! ! !

Tom Perry
kd4ufd@arrl.net

----------------------------------------------------------------------

Subject: APRSWorld
From: Robbie - WA9INF <mwrobertson@comcast.net>
Date: Wed, 16 Jun 2004 15:18:19 -0500
X-Message-Number: 63

Hi,

Anyone know what the deal is with APRSWorld Server???? No map serving 
here...

Robbie

----------------------------------------------------------------------

Subject: Re: APRSWorld
From: "DG2JW" <dg2jw@privateasylum.com>
Date: Wed, 16 Jun 2004 23:25:05 +0300
X-Message-Number: 64

quote
"The database is currently being copied over to the new 160 gigabyte
RAID array. It should be back up by about 6pm central time. -Jim "

Julian

----------------------------------------------------------------------

Subject: Re: APRS-IS vs RF backbones
From: n5oom@arrl.net
Date: Wed, 16 Jun 2004 16:03:37 -0500
X-Message-Number: 65

On 16 Jun 2004 at 12:23, Bob Snyder wrote:

>On Tue, Jun 15, 2004 at 06:06:47PM -0400, Danny wrote:
>Lets face it,
>the internet is everywhere. In the event of a disaster, you cant be
>more than a couple hops to an IGATE. Replacing what we already have
>with APRS-IS with our own MUCH SLOWER and LESS RELIABLE backbone
>system doesnt make sense.
> 
>[Whatever Mail client you use doesn't seem to wrap lines properly]
> 
>The Internet is everywhere. But most providers I know of tend to
>aggregate up a region's traffic to a single Point of Presence, and
>connect that back using larger pipes to the provider's backbone, to a
>regional interconnect point, or both. Often the POP is co-located with a
>regional interconnect, since that saves on transit costs. The POPs and
>the interconnects are generally hardened with protected transport,
>UPS/generators, etc, but hardening against rising flood waters or bomb
>damage is challenging.

Directway! Now, I don't know where Directway's headend is...

----------------------------------------------------------------------

Subject: Re: APRS-IS vs RF backbones
From: Drew Baxter <droobie@maine.rr.com>
Date: Wed, 16 Jun 2004 17:33:28 -0400
X-Message-Number: 66

For some weird reason, I believe Direcway's main data center/NOC is in 
Colorado. HNS is based in Germantown, MD though.

--Droo, K1XVM

At 05:03 PM 6/16/2004, n5oom@arrl.net wrote:
>Directway! Now, I don't know where Directway's headend is...

---

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