home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
QRZ! Ham Radio 4
/
QRZ Ham Radio Callsign Database - Volume 4.iso
/
digests
/
tcp
/
940242.txt
< prev
next >
Wrap
Internet Message Format
|
1994-11-13
|
10KB
Date: Sat, 29 Oct 94 04:30:03 PDT
From: Advanced Amateur Radio Networking Group <tcp-group@ucsd.edu>
Errors-To: TCP-Group-Errors@UCSD.Edu
Reply-To: TCP-Group@UCSD.Edu
Precedence: List
Subject: TCP-Group Digest V94 #242
To: tcp-group-digest
TCP-Group Digest Sat, 29 Oct 94 Volume 94 : Issue 242
Today's Topics:
If they're gonna sell frequencies, what about these?
Info on packet radio protocols for interactive wireless cabl
Thanks all
Users and 9600 baud (2 msgs)
Send Replies or notes for publication to: <TCP-Group@UCSD.Edu>.
Subscription requests to <TCP-Group-REQUEST@UCSD.Edu>.
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the TCP-Group Digest are available
(by FTP only) from UCSD.Edu in directory "mailarchives".
We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Fri, 28 Oct 94 11:17:35 EDT
From: Fred Goldstein <fgoldste@BBN.COM>
Subject: If they're gonna sell frequencies, what about these?
I am not nearly as up in arms about this as many hams...
How cum? Look... do any of you USE any of that frequency band?
We lost most of 2300-2450 some years ago and are losing more, but
we still have the 2300-2310 section where the "weak signal" work,
such as packet (or at least one side of a duplex system) can take
place. Are a thousand hams total nationwide using the affected
spectrum? If the feds auction it off for, say, $500M (not all
that unthinkable given today's auction pricing for narrower
chunks), that would be about $500k/ham. Hell, that's not even
a "save the frequency for educational blah blah" use. We just
plain don't use all that space. The FCC banked it with us and
now it's nice, clean, virginal space and it's ready for prime time.
We do such a bad job with the space we have I just can't get all
upset about this, so long as we end up with a few usable chunks.
BTW, Frezza's UHF TV argument isn't all new, but isn't all that
simple either. Back in '73 as a computer programming exercise,
I wrote some FORTRAN code to "nest" TV channels, following FCC
regs, such that all VHF could move up to UHF. It almost fit. BUT
the rules for allocating UHF channels are tricky. You can't have
stations located at the "image" distance (7-8 channels? I forget)
in the same market, and while it may have been lifted, there was
a taboo (that's the technical term they use) on being 2, 3, 4 or
5 channels apart due to "intermod". These were developed around
1955 tuners. The FCC had a project to develop a better TV tuner
but wimped out. So while the spectrum could be used better,
it isn't easy to suddenly make practically all existing TV tuners
obsolete by lifting the taboos.
--------
Fred R. Goldstein fgoldstein@bbn.com
------------------------------
Date: Fri, 28 Oct 1994 16:09:24 GMT1
From: pryan@sligo.screen.ie
Subject: Info on packet radio protocols for interactive wireless cabl
Hi Phil,
I'm a bit new to packet radio but have bits and pieces of experience
with ethernet based networking and telecoms. I'm looking for info on
protocols for packet radio that would suit a specific application. We
are afiliated with a cable and wireless cable provider in Ireland who
wants to develop a mechanism for interactive wireless cable. Wireless
cable is if you don't already know, TV distribution by microwave at
2.5Ghz. We are keen to implement a reverse channel for signalling
from the subscriber back to the headend for interactive games, Video
on Demand etc. We are already investigating kit for ethernet (TCP/IP)
over cable to implement the reverse channel in that case. What are
the suitable protocols for radio for such a system, where could I get
more info ???
We are working with Philips Netherlands on this issue and they would
like to use X25 in the reverse path, their telephony video on demand
server uses this so they would like of course to use the same
servers.
If you need any detail please email to the above address.
Thanks in advance.
Padraig.
**********************************************************
* Padraig Ryan pryan@sligo.screen.ie *
* *
* _/_/_/ Screenphones Ltd., Tel : +353 71 41991 *
* _/_/_/ Finisklin Ind. Est., Fax : +353 71 41985 *
* _/_/_/ Sligo, Ireland. *
**********************************************************
------------------------------
Date: Sat, 29 Oct 1994 00:21:08 +1000 (EST)
From: Garry Hawgood <garry@cyanea.apana.org.au>
Subject: Thanks all
To all of you who responded to my query re pcmcia ethernet adaptors, thank
you.
On advice I bought a D-Link adaptor today and have it working just fine
with both nos and lantastic. (using the ne2000 packet driver)
Thanks again.
--
------------------------------------------------------------------------
Garry Hawgood Phone (h) +61 7 2790278 (07 2790278)
Riverhills (m) +61 18 645940 (018 645940)
Brisbane (w) +61 7 8663447 (07 8663447)
Internet garry@cyanea.apana.org.au or vk4ke@vk4kiv.qut.edu.au
------------------------------------------------------------------------
------------------------------
Date: Fri, 28 Oct 1994 14:14:49 -0600 (MDT)
From: LARSEN KARL AMSRL-SL-EC 505-678-3145 <klarsen@arl.army.mil>
Subject: Users and 9600 baud
Talking with Roy N5RG today he said something that is right. WWe
were talking about our 9600 baud modems and radios. And about only 2
other 9600 baud stations. Roy said that while information theory and
experiance tells us to run 1200 baud on the long runs but make the local
links much faster, like 9600 baud.
The problem is that the ordinary ham isn't capable of making 9600
baud work. The 2 stations in El Paso, TX which are run not as nodes but
as personal JNOS connects to the network are having lots of problems.
This is not do to weak signals. They both have line-of-sight to the node
#ELP. But they are not Engineers and don't have an oscilliscope to
display eye waveforms or a Service Monitor to set frequency and transmit
deviation. So they are not able for reasons of training and equipment to
get 9600 baud systems working.
So lets be reasonable and admit that the new No Code Ham is not
going to have a scope, or freq. meter or any of that stuff. But if we are
successful we infect them with a desire to try TCP/IP and packet radio in
general. These fine people will buy a tnc and with lots of trouble get it
connected to the new HT they just got.
At 1200 baud it's a good guess the radio will be fine for the
narrow 1200 baud spectrum. They get it running and begin to learn about
packet and computers and the fun. After awhile they may want to try a
faster system. We must either get smart and design a 2400 or 4800 baud
modem that will ALSO run fine with the HT, and give them more speed. But
we must be honest with them and say NO! Do NOT buy a 9600 baud modem!
-karl k5di
------------------------------
Date: Fri, 28 Oct 94 14:42 PDT
From: bruce@pixar.com (Bruce Perens)
Subject: Users and 9600 baud
[I'm re-directing this thread to NETSIG@TAPR.ORG . Please do not follow-up]
[to TCP-GROUP@UCSD.EDU, there is no reason to use _two_ lists. - Bruce]
Karl Larsen said:
> Roy said that while information theory and experiance tells us to run
> 1200 baud on the long runs but make the local links much faster,
> like 9600 baud.
You must mean user-to-BBS connections, as 1200 wouldn't be practical for
a backbone.
> The problem is that the ordinary ham isn't capable of making 9600
> baud work.
I made 9600 work with only a voltmeter. I used off-the-shelf radios
and TNCs (TEKK and Kantronics), which makes a big difference. I used a
$17 Radio Shack TV antenna and a 4:1 coaxial balun. I wouldn't expect a
new ham to convert a Micor. I set the voltage to the input of my TEKK to
the one I was told would make it deviate about 3 KHz. It worked. Big deal.
> But they are not Engineers and don't have an oscilliscope to
> display eye waveforms or a Service Monitor to set frequency
> and transmit deviation. So they are not able for reasons of
> training and equipment to get 9600 baud systems working.
Kantronics says to measure the voltage at the BER test point of their
TNC, as it is more accurate than eye patterns. If I had a TAPR modem
I'd have no choice but to look at eye patterns.
> So lets be reasonable and admit that the new No Code Ham is not
> going to have a scope, or freq. meter or any of that stuff.
OK. They don't need them.
Also, you are completely discounting the fact that the world is full
of Elmers. I don't have a service monitor (though I admit to lusting
for one) but when I really need one, I can drive over to a buddy and
use his.
> We must be honest with them and say NO! Do NOT buy a 9600 baud modem!
I wouldn't suggest any new ham buy the TAPR modem, but there is good
off-the-shelf equipment now.
The problem with running a LAN at 9600 with these two-watt radios
is that you need a bit-regenerating repeater to eliminate the
hidden-transmitter problems so that everyone can use directional
antennas pointing at the repeater, everybody can hear each other,
etc. So let's build repeaters to make it easier for the naive user
to join a LAN.
Karl, a while back you were arguing why it was necessary for us to
build software for people who could not afford a 486. Now you have a
486 and I don't hear that argument any longer. Could it be that you're
going to drag your feet on 9600 for another two years and then join
that bandwagon too?
Thanks
Bruce AB6YM
------------------------------
End of TCP-Group Digest V94 #242
******************************