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ZL3AI > APRDIG 24.03.03 11:08l 237 Lines 9280 Bytes #999 (0) @ WW
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To : APRDIG@WW
TAPR APRS Special Interest Group Digest for Saturday, March 22, 2003.
1. Re: digi radio needed
2. Re: digi radio needed
3. APRS Authors. APRS in Japan
4. Re: digi radio needed
5. Re: Homeland Security Threat Level Beacons
6. Re: MJF-9030 on HF APRS 10.151 ? Anyone?
7. Re: APRS Authors. APRS in Japan
8. Re: APRS Authors. APRS in Japan
9. Re: digi radio needed
10. Any Idea what is causing this?
11. Re: APRS Authors. APRS in Japan
12. Re: Any Idea what is causing this?
13. Re: APRS Authors. APRS in Japan
14. Re: Any Idea what is causing this?
15. Rejected Relay
16. EMail server back up
17. Re: EMail server back up
18. Re: Any Idea what is causing this?
19. digi radio needed
20. CWxxxx named WX stations
21. Re: CWxxxx named WX stations
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[commercial content deleted]
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Subject: APRS Authors. APRS in Japan
From: Bob Bruninga <bruninga@usna.edu>
Date: Sat, 22 Mar 2003 08:50:18 -0500 (EST)
X-Message-Number: 3
On Fri, 21 Mar 2003, Bill Vodall wrote:
>I automated the data-mining of DX packets.
This reminds me! We need to get JAPAN on the APRS map. But they use a
ham radio navigation program called NAVITRA which is stagnant, limited,
and not linked to the APRS-IS. The Japanese model of the D7 and D700 both
do NAVITRA. Here are the facts on NAVITRA:
1) It uses only ONE on air packet type: $PNTS......
2) $PNTS carries LAT/LONG/CSE/SPD/ICON and 20 chars status
just like D7 and D700 in USA (we use shorter Mic-E format).
3) NAVITRA has no messaging capability.
4) Their only available NAVITRA mapping system requires the ham
to purchase a $xxx commerical MAPING CD program.
Because of #3 and #4, NAVITRA is not popular like APRS. But still, they
have digipeaters using WIDE and with 3 hops can cover most of Japan
(population centers).
GREAT IDEA!!! We have talked about someone writing an APRS<>NAVITRA
converting IGate, but the lack of a messaging capability (which is the
only thing that routinely goes through an IGate) makes this a ho-hum
lack-luster project....
BUT! I just realized that the Japanese D7 and D700 do have the same
DX-LIST memories as our D7A and D700A have. And these DX lists can
display up to 40 characters in each of the 10 DX memories. Thus, an
APRS<=>NAVITRA igate could simply convert APRS messages into DX-CLUSTER
format in Japan for reception by any mobile and convert $PNTS into APRS
format for us to see.
SECOND ORDER EFFECT: NAVITRA is only a ham radio car navigation system.
Because there is no messaging, there is little incentive for base-station
use for communicating with mobiles, and therefore there is no software for
communicating between base stations either...
BUT! By introducing a messaging capability into their NAVITRA system
(using the DX format), and simply adding $PNTS format decoding into many
of the APRS software that we use, (that can use any source of BIT-MAP
maps), then maybe base station use will increase. Then once they begin
using our APRS programs to communicate, maybe APRS will grow in Japan.
APRSdos has always decoded $PNTS format (Im not sure if we put it in the
APRS spec) but this NEW idea of communicating to them using the DX format
is a whole new idea..
I had put up a NAVITRA web page years ago to show how to decode $PNTS:
http://www.ew.usna.edu/~bruninga/navitra.html
But back then I was trying to STUFF message info into the 20 bytes of text
in each $PNTS position report. I think this DX-LIST idea is a whole new
start and GREATLY simplifies everthing. So ignore most of that WEB page
about the message stuff until I get a chance to update it to the DX
format.
SUMMARY:
1) IGates in JAPAN will convert $PNTS packets heard on the air to
standard APRS foremat (as I detailed in my WEB page above) and inject them
into the APRS-IS. AND THIS MUST BE A STANDARD CONVERSION!
2) Any APRS message packet addressed to an RF user in Japan in range of an
IGate, will be converted to DX-LIST format for gating to RF and display on
the mobile.
3) Any on-air DX-LIST format packet received in Japan will be converted
back and "displayed" as if it were an APRS message in APRS software.
Would that do it? With minimum impact on APRS and maximum transparency?
Currently there are about 100 NAVITRA users in Japan. But you can
imagine, they are the important hams! If APRS caught on in Japan, maybe
we would see more products supporting it!
Bob
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[commercial content deleted]
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Subject: Re: Homeland Security Threat Level Beacons
From: "Spider" <spider@rivcom.net>
Date: Sat, 22 Mar 2003 07:30:32 -0700
X-Message-Number: 5
Eric!
This script is now running on FireNet from Region 1 and Region 6 and WetNet
thanks to Curt. James may run it in Region 2, do not know yet he's been
seen working in the garden again!!!.
Bill! Thank you! I've been looking for something like this.
Jim, WA6OFT
Coordinator, FireNet
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Subject: Re: MJF-9030 on HF APRS 10.151 ? Anyone?
From: "James Lux" <aprssig@luxfamily.com>
Date: Sat, 22 Mar 2003 9:23:17
X-Message-Number: 6
That's a pretty wide temperature range to stay on frequency with, but
here's an idea or two..
You probably want to be within a few hertz of the right frequency.. Since
you're at 10 MHz, that implies a temperature stability of better than 1 ppm
(10 Hz), which is quite tight, particularly over that temperature range.
You'd probably like to be in the 0.5-0.2 ppm area.
Presumably, you don't need to broadcast the weather every second, but
rather, like the Cal Dept Water Resources stations around here, you beacon
it out once per hour.
You need a processor (not very complex, but you'll have to do some
programming) that will come alive at T-10 minutes or so, and fire up a GPS.
After a minute or so, when it locks up, the GPS will give you a 1 pps tick,
with which you can count the processor's internal clock rate, and the rate
of your transmitters XO. From that you can determine the modulation
frequencies for your packet that will make the output frequency come out
right. Then, generate the modulated signal using the phasing SSB
technique; it's easy to have the processor generate a pair of quadrature
signals (generate at 4x, then a couple flipflops). Filter out the "wrong"
sideband. Maybe have the processor generate the two tones at, say, 20 kHz
away, so the image is 40 kHz away from the desired signal and easier to
filter.
You could probably use one of those nifty high efficiency Class F
amplifiers that use a single cheap MOSFET, since the application is very
narrow band. A suitable LC network on the output (which you need anyway as
a tank for the amplifier) can help reduce the harmonic content to make it
legal.
Another, similar approach, would be to hook a varactor across the crystal,
driven by a DAC. The GPS reference would be used to determine what two
voltages on the DAC would generate the two tones you need for the packet
transmission.
You could also try to receive the 10 MHz WWV signal, and beat it against
your 10.150 oscillator, and look at the 150 kHz difference
Jim, W6RMK
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Subject: Re: APRS Authors. APRS in Japan
From: Bob Bruninga <bruninga@usna.edu>
Date: Sat, 22 Mar 2003 12:07:17 -0500 (EST)
X-Message-Number: 7
On Sat, 22 Mar 2003, Bob Bruninga wrote:
>I had put up a NAVITRA web page years ago to show how to decode
>the Japanese $PNTS format:
>http://www.ew.usna.edu/~bruninga/navitra.html
NEW WEB PAGE: http://www.ew.usna.edu/~bruninga/aprs/navitraDX.html
I just updated this web page and changed the link to the NEW format using
the DX-LIST format. It sure looks neat. I tested it on the air with my
D7 and D700 and its a great way to send an additional 30 to 40 or even 50
characters to these radios DX list display.
Remember, the DX list display has always had a format (called APRS
RESOURCE) built into APRS. But now we have just found a great use of
it...
de WB4APR, Bob
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Subject: Re: APRS Authors. APRS in Japan
From: Jeff King <jeff@aerodata.net>
Date: Sat, 22 Mar 2003 12:30:15 -0500
X-Message-Number: 8
Dumb question, but since NAVITRA is so limited (100 users in a country
with more hams then the U.S) and not widely deployed, wouldn't it be easier
just to pitch APRS to them instead? Their amateurs seem technically astute
so they will either see the advantage or not.
Certainly would save alot of work and is the most direct path to the goal
you had in mind. The "100 users" are early adopters so getting them to
change shouldn't be that hard.
If not, your big issue is going to be language and culture. Look how long
it took for UI-View to become the dominant APRS program in the States....
and we (kinda) speak the same language.
--
Jeff King, jeff@aerodata.net on 3/22/2003
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