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ZL3AI > APRDIG 07.04.07 06:06l 277 Lines 9498 Bytes #999 (0) @ WW
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Subj: [APRSSIG] Vol 34 #4, 1/3
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To : APRDIG@WW
Today's Topics:
1. Python script to upload packets to APRS-IS (Bill Borgstrom)
2. RE: Python script to upload packets to APRS-IS (AE5PL Lists)
3. Deviation meters ('Scott Miller')
4. Re: Deviation meters (Floyd Rodgers)
5. Re: Deviation meters (Ray Wells)
6. Re: Deviation meters (Stephen Brown Jr)
7. RE: Deviation meters ('Scott Miller')
8. Re: Deviation meters (Stephen Brown Jr)
9. Re: Deviation meters (Stephen H. Smith)
10. RE: Deviation meters (Robert Bruninga)
11. RE: Deviation meters (Richard Hoskin)
12. RE: Deviation meters (Alan P. Biddle)
13. Re: Deviation meters (Ray Wells)
14. RE: Deviation meters (Ray McKnight)
15. RE: Deviation meters ('Scott Miller')
16. New Orleans, Operating Freqs and spam (Robert Bruninga)
17. Re: Deviation meters (C J Rohrer Jr)
18. Re: New Orleans, Operating Freqs and spam (Keith VE7GDH)
19. Re: Deviation meters (John)
20. Re: Deviation meters (Stephen H. Smith)
21. RE: Deviation meters (Alan P. Biddle)
22. Re: New Orleans, Operating Freqs and spam (Bill Vodall WA7NWP)
----------------------------------------------------------------------
Message: 1
Date: Wed, 4 Apr 2007 11:50:17 -0700 (PDT)
From: Bill Borgstrom <bill_borgstrom@yahoo.com>
Subject: [aprssig] Python script to upload packets to APRS-IS
Below is a Python script to upload packets to APRS-IS.
It is quick and dirty but it works. I test it on WinXP and SuSE linux.
=====================================================
import sys, time
from socket import *
serverHost = 'second.aprs.net'
serverPort = 10151
password = '12345'
address = 'N9TN-1>APRS,qAR,N9TN-VS:'
position = '=3349.13N/11153.55W-'
# comment length is supposed to be 0 to 43 char. long-
this is 53 char. but it works
comment = 'N9TN Python script -- Sky Ranch airport -
Carefree AZ'
packet = ''
delay = 15 # delay in seconds - 15 sec. is for testing
- should be 20 to 30 min for fixed QTH
def send_packet():
# create socket & connect to server
sSock = socket(AF_INET, SOCK_STREAM)
sSock.connect((serverHost, serverPort))
# logon
sSock.send('user N9TN-1 pass ' + password + '
vers "N9TN Python"\n')
# send packet
sSock.send(address + position + comment +
'\n')
print("packet sent: " + time.ctime() )
# close socket -- must be closed to avoid
buffer overflow
time.sleep(15) # 15 sec. delay
sSock.shutdown(0)
sSock.close()
packet = address + position + comment
print (packet) # prints the packet being sent
print (len(comment)) # prints the length of the
comment part of the packet
while 1:
send_packet()
time.sleep(delay)
------------------------------
Message: 2
Date: Wed, 4 Apr 2007 14:42:04 -0500
From: "AE5PL Lists" <HamLists@ametx.com>
Subject: RE: [aprssig] Python script to upload packets to APRS-IS
Hi Bill,
One correction:
>-----Original Message-----
>From: Bill Borgstrom
>Posted At: Wednesday, April 04, 2007 1:52 PM
>Subject: [aprssig] Python script to upload packets to APRS-IS
>
>=====================================================
>import sys, time
>from socket import *
>
>serverHost = 'second.aprs.net'
>serverPort = 10151
>password = '12345'
>address = 'N9TN-1>APRS,qAR,N9TN-VS:'
>position = '=3349.13N/11153.55W-'
># comment length is supposed to be 0 to 43 char. long-
>this is 53 char. but it works
>comment = 'N9TN Python script -- Sky Ranch airport -
>Carefree AZ'
>packet = ''
>delay = 15 # delay in seconds - 15 sec. is for testing
>- should be 20 to 30 min for fixed QTH
>
>def send_packet():
> # create socket & connect to server
> sSock = socket(AF_INET, SOCK_STREAM)
> sSock.connect((serverHost, serverPort))
> # logon
> sSock.send('user N9TN-1 pass ' + password + '
Should be 'user N9TN-VS pass ' (the qAR,N9TN-VS means "gated to APRS-IS
by N9TN-VS" so N9TN-VS should be the "station" that is logging in).
73,
Pete Loveall AE5PL
pete at ae5pl.net
------------------------------
Message: 3
Date: Wed, 4 Apr 2007 13:57:34 -0700
From: "'Scott Miller'" <scott@opentrac.org>
Subject: [aprssig] Deviation meters
Since proper deviation is one of the most critical (and most neglected)
settings for an APRS transmitter, I thought I'd look into the feasibility
of coming up with a simple meter kit.
So far I haven't found any existing, simple kits, but I seem to remember
one that was based on a single LED. Anyone remember that one, or know
where I can find it? If there's already something suitable out there, I
don't want to have to reinvent it.
Scott
N1VG
------------------------------
Message: 4
Date: Wed, 4 Apr 2007 14:53:43 -0700 (PDT)
From: Floyd Rodgers <kc5qbc@swbell.net>
Subject: Re: [aprssig] Deviation meters
AEA used to make one I think. I have something with LED's that works on 2m
& 70cm. Let me check...
------------------------------
Message: 5
Date: Thu, 05 Apr 2007 07:58:41 +1000
From: Ray Wells <vk2tv@exemail.com.au>
Subject: Re: [aprssig] Deviation meters
'Scott Miller' wrote:
>Since proper deviation is one of the most critical (and most neglected)
>settings for an APRS transmitter, I thought I'd look into the feasibility of
>coming up with a simple meter kit.
>
>So far I haven't found any existing, simple kits, but I seem to remember one
>that was based on a single LED. Anyone remember that one, or know where I
>can find it? If there's already something suitable out there, I don't want
>to have to reinvent it.
>
>Scott
>N1VG
Deviation certainly raises its head periodically, but deviation, alone,
is not the only consideration.
Audio drive to the transmitter play an equally, and maybe more,
important role.
A transmitter can be set to deliver no more than, say, 3.5khz deviation,
which is probably close to ideal for data in a nominally +/-5khz system.
However, just having the correct deviation will not guarantee success.
More important is having the transmitted amplitude of the two tones in
the correct ratio, which is approximately 2 to 1 in favour of the high
tone. This assumes that pre-emphasis/de-emphasis is being employed on
the network at the rate of 6dB/octave, something that is more the norm
than the exception.
The tones arriving at the receiving end TNC/modem must be approximately
equal in amplitude. This is the most important point to consider.
Getting back to our transmitter that is delivering 3.5khz deviation. If
the audio drive to that transmitter is sufficiently high, its audio
limiter/compressor can result in a transmitted signal where the
amplitude of both TNC tones is equal. At the receiving end, and after
de-emphasis, the TNC is presented with a signal in which the high tone
is approximately half the level of the low tone. Some decoders simply
baulk at this and won't decode. The XR2211 comes to mind.
Most systems are more tolerant of incorrect (within reason) deviation
that they are of grossly uneven tone levels, and the latter is more
easily achieved!
In the absense of a service monitor or oscilloscope, and if a simple,
peak reading device is used, adjust the audio drive until the desired
level is achieved, then back it off just a tad.
Ray vk2tv
------------------------------
Message: 6
Date: Wed, 4 Apr 2007 18:13:17 -0400
From: "Stephen Brown Jr" <stephen.brown75@gmail.com>
Subject: Re: [aprssig] Deviation meters
I'd like to see a kit like that in production, I would buy one for sure! I
have 2 radios going full time with packet/aprs and just set them both till
"they worked", it would be better to use a meter to set it more accurately.
73's and gl
Stephen
K1LNX (ex N1VLV)
------------------------------
Message: 7
Date: Wed, 4 Apr 2007 15:15:50 -0700
From: "'Scott Miller'" <scott@opentrac.org>
Subject: RE: [aprssig] Deviation meters
>Audio drive to the transmitter play an equally, and maybe more,
>important role.
And this is really what I'm hoping to come up with a tool to set - i.e.,
set your tracker/TNC to calibrate mode (alternating tones) and set the
audio drive level to get appropriate deviation. Assuming the transmitter's
not so out of whack that at 3.2 kHz deviation it's clipping the high tone
already.
>More important is having the transmitted amplitude of the two tones in
You're preaching to the choir. =] Of course, as long as we've got D700's
and such out there, there's no getting around the fact that some stations
will transmit with no pre-emphasis. I made a point of adding a
pre-emphasis circuit to my T2-135 board, since the DR-135T doesn't provide
pre-emphasis on the TNC input (not the one from the internal header,
anyway). I may add a jumper on future versions to bypass it if needed,
though.
>In the absense of a service monitor or oscilloscope, and if a simple,
>peak reading device is used, adjust the audio drive until the desired
>level is achieved, then back it off just a tad.
This is what I've encouraged users to do. Still, it'd be nice to have a
small board that'd give you at least a basic indication that you've got it
set right, even if it wasn't very sensitive and required the radio to be
tuned to a known frequency. I've got an Agilent service monitor, myself,
and it's wonderful for checking my relative tone levels and deviation, but
even used and several years old it was more than $3,000. I'd like to be
able to point people to an affordable option that's somewhere between the
extremes of 'service monitor' and 'set it by ear'.
Scott
N1VG
------------------------------
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