wheatley@inuxi.UUCP (Steven Wheatley) (12/31/85)
Gateway: The ARRL Packet-Radio Newsletter
Volume 2, Issue 9
December 20, 1985
Published by:
ARRL
225 Main Street
Newington, CT 06111
Editor:
Ed Raso, WA2FTC
Beginners' Packet Net
"A beginners' packet net has been started in the Lowell/Lawrence
Massachusetts area. The net meets Friday evenings at 8:00 PM
alternately on the Lowell repeater (145.490 MHz), and the
Haverhill repeater (146.625 MHz). Conductor of the net is Joe
Demers, WA1WLV. Topics of discussion in recent weeks have been:
PBBS operation, Terminal programs for computers and TNC
operation. The purpose of the net is to help the packet-radio
neophyte."
From NEPRA PacketEar
Upper East Tennessee Packet
Late this year, packet radio arrived in Upper East Tennessee with
the installation of the WB4BFS-2 digipeater. Located on top of
Holston Mountain, the digipeater boasts an impressive height of
4300 feet above sea level. Links are now common to West Virginia
via WB8FQJ-1 and into South Carolina and Georgia via W4FX-1. A
local PBBS is also operational under the call sign of W4XS. Mail
is being forwarded to South Carolina and Georgia. Further
west, Knoxville, Tennessee packeteers are active with digipeater
KB4NK-1 and packet bulletin boards K4EID and KC4OI. All VHF
activity is presently on 145.01 MHz.
Via W4XS
Packet-Radio Band Plan Proposal
The following frequency plan for Michigan packet radio was
adopted for further discussion by the Packet Radio In Southern
Michigan (PRISM) Spectrum Planning Committee.
144.91 MHz Experimental and QRP
144.93 MHz Local Area Network
144.95 MHz Local Area Network
144.97 MHz Local Area Network
144.97 MHz Non digipeated packet (simplex)
145.01 MHz Inter-LAN and mail forwarding
145.03 MHz Local Area Network
145.05 MHz Local Area Network
145.07 MHz Local Area Network
145.09 MHz Experimental and QRP
"Michigan Repeater Council policy does not allow coordination of
packet channels on 144-148 MHz. These are designated as simplex
channels that may be used in any mode by amateurs at any given
location. Activity in this area is by "gentleman's agreement"
Anyone is allowed to install a digipeater or a PBBS. The type of
packet activity allowed on a particular channel is determined by
the need, not by the council. The above listed frequencies are
recommended as a guideline for a "gentleman's agreement" in
Michigan.
Frequencies for Local Area Networks (LANs) would be activated in
the following order:
1) 145.03 MHz
2) 145.05 MHz
3) 145.07 MHz
4) 144.97 MHz
5) 144.95 MHz
6) 144.93 MHz
The lowest numbered available frequency would be used, unless it
poses a potential traffic conflict with the desired LAN.
The objective is to avoid conflicts with existing voice
operations on the above frequencies. We feel that it is
important for packet radio to expand in a contiguous group of
frequencies, and not all over the 2 meter band. This will help
"carve out" a segment of 2 meters that ultimately will become
recognized as the "packet sub-band."
From PRISM
PACKET RADIO ON THE MOVE-- THE CLUB CONNECTION
(Fifth in a series by Steve Place, WB1EYI, Manager, ARRL
Volunteer Resources Office)
Pierre Packette, ace techno-klutz and purveyor of pithy packet
misconceptions, asks that we recap what we're trying to
accomplish. It seems that amidst the fun and frolic of his first
packet-radio club meeting he's forgotten why he's doing what he's
doing.
Your local packet-radio user base is needed before packet radio's
potential can be met. As most of the technical pieces are now in
place and the heretofore scarce TNCs now abound, the sooner you
initiate the great unwashed masses in the ways of the Packeteer,
the better. A time-tested approach for accomplishing your
objective -- one that gives you the "biggest bang for the buck"
(that is, produces the greatest number of motivated recruits for
the amount of effort you invest) -- is the well-organized
campaign to form a local packet radio club.
Your primary objectives are to (1) increase the number of packet-
radio users within a 50-mile radius; (2) develop the variety of
packet-radio applications in your area; and (3) increase the
participation of others beyond your initial core/corps of
Packeteers in developing, supporting and maintaining local
packet-radio projects (applications).
The strategy? Organize your recruitment effort in advance. Only
then take the first in the straightforward series of steps that
will pilot you safely through the rocky shoals of your first club
meeting and chart your course for the year ahead.
In recent installments we've covered inviting key Amateur Radio
leaders to the first open meeting; publicizing that first meeting
among hams and non-hams alike in your desired area of coverage;
and kicking off the meeting with the warm welcome, the "chatty"
audience assessment, and the packet radio overview-tutorial.
Steps yet to be covered are the hands-on demonstration, the
special-interest working groups and the post-meeting social get-
together.
Baptism of Fire -- The Demonstration
or
Let Their Fingers Do the Walking
Time for the long-awaited demonstration, the key
move in the packet-radio-club ploy. Your mission
is to
* demystify packet-radio operation, calm your guests' techno-
fears and convince each potential Packeteer that acquiring the
needed gear is all that stands between him and packet-radio
nirvana;
* bring your guests to a point where they understand the
advantages, the potential and the fun of packet radio.
Do everything in your power to stack the deck in your favor. And
by preparing thoroughly, deal Murphy a bust hand. A lot of work?
Yes. But a lot of work that will have to be done only once if
you do it right this time.
When you and your cohorts lay the groundwork for this, the big
moment, come as close as you possibly can to achieving the ideal.
Get every one of your cohorts involved -- a successful show is
not a one-man show. PREPARE!
Equipment
* If at all possible set up at least three VHF packet stations
in the meeting room, preferably each with a large-screen monitor
so those who are not at the keys will nonetheless stay involved.
* Gather as large a variety of appropriate gear as possible to
display the various options from which your newcomers will soon
have to choose. For example, a Commodore C 64 with a TNC, black-
and-white portable TV "monitor" (check first for TVI) and a bare-
bones 2-meter handitalkie),
or
the battery-operated portable packet station (for example, a TRS-
80 Model 100, a TAPR TNC 2, a simple homemade C-cell battery
power supply and a typical, small 2-meter HT. Don't forget the
typical home station (for example, a personal computer like an
Apple //e or IBM PC, any compatible TNC and a modern mobile or
desktop 2-m rig).
Redundancy
Have a few extra TNCs, 12-V power supplies, 2 meter radios and
computers available on site -- with the necessary interfacing
cables! If any of the primary station components should crash,
you'll be able to swap out "black boxes" immediately. Yes, we
know this is asking a lot, but try to get as close to this ideal
as you can given your local resources and sophistication. Don't
forget that Murphy lies in the wings, poised to strike at the
first opportunity. As any experienced ham (particularly a
contester) can confirm, the likelihood of something going wrong
at a particular moment is inversely proportional to the ease with
which you can fix the problem at that moment, and directly
proportional to the importance of its working correctly.
Scheduling and Ring-Out
Make sure that a few scattered packet stations are manned and
standing by at the appointed hour. A day or two and again
roughly an hour before your meeting, check to see that the local
digipeater is working. Likewise, run the local PBBS and any
other normally accessible bells and whistles through their paces.
Rehearsal
A smooth demonstration will do a lot to convince your future
fellow Packeteers that packet radio really is simple, and that
you're not. Put in the time. Yes, it's hard work. But doing it
right the first time will ensure that the first time will be your
last time. Ideally, everyone will agree to a dry run a couple of
weeks before D-Day. Certainly, the on-site crew must take the
time to make all the mistakes "backstage."
The Sequence
Start simple and follow a logical progression to arrive at
routine packet-radio operation. Start with a single station.
Connect with yourself. Note that the person speaking should not
be the one plying the keyboard; also, the operator at the keys
should not run ahead of what the narrator is explaining. That
alone should take a little practice to perfect.
Keep the focus in the room for a few minutes while you explain
the basics of firing up the equipment and establishing a
connection. Next, connect with a station across the room and
converse for a while. Then connect with a third station via
Station #2.
To further the pretense that everyone can keep tabs on every one
else, minimizing the apparent magic, demonstrate the advantages
of packet radio over other digital modes. What happens if the
link between two connected stations breaks down for a while?
What if the signal suddenly falls into the noise or there's very
strong interference? How could reliable communications ever be
conducted via meteor scatter, so transient a phenomenon? A
simple way to simulate the "band" falling out for a few seconds
-- disaster for CW or ASCII transmissions -- is to walk over to
the radio at Station #2 and turning off the radio. Make sure
that another rig is monitoring the frequency with the audio
turned up. Station #1 keeps trying to reach Station #3 via
Station #2; no such luck. Turn the radio back on in 15 or 20
seconds. Voila! With a little creativity you should be able to
devise some clever simulations yourself.
Next, turn the focus to the world beyond your cozy meeting room.
Link to another station in the room but via a local digipeater.
Then turn to your busy local packet frequency and leave a station
in the room in monitor mode; let everyone observe what's going on
in the real world. Next, pass out network maps, if they exist
for your area. Don't forget that to your audience, knowing what
sequence of stations to link through to reach a given destination
seems as far fetched as copying 1200 bit/s ASCII by ear!
Finally, turn them loose! Have a control operator/tutor/Elmer at
each station to show them once again how to play the game and let
each guest do his thing for five minutes or so. (It helps to
have kept the coffee hot in anticipation of the friendly chaos
that will ensue.) Observe the rules, especially when control
operating for non-ham guests.
If you get this far without any casualties, you've got it licked.
All that's left is to regain loose control of the festivities,
and sustain the enthusiasm by letting them propose and work out
pie-in-the-sky applications of their new-found obsession. We'll
cover this next time.
From WB1EYI
TNC 2 Update
"Noting the improvements made in the TNC 2 Rev 2 design, many of
you have contacted TAPR requesting information on obtaining parts
for the various upgrades listed in the October, 1985 PSR
Quarterly.
After listening to your calls and reading your letters, we are
pleased to announce that we are ordering sufficient parts to send
to every TNC 2 Rev 1 owner a "care package" consisting of the
27C256 EPROM, second 8k static RAM, RF Chokes and miscellaneous
capacitors, along with a corrected copy of the PSR article.
If all goes well, the package should arrive in time to be a
stocking stuffer.
The price? Hey, this is TAPR. There will be no charge...
Thank you for your support. Happy holidays from TAPR!"
From TAPR
Work Continues On SAREX II
"Many of you are aware that we are hard at work to get SAREX II
built. SAREX II is an acronym for Shuttle Amateur Radio
EXperiment; SAREX I was the slow-scan TV that W0/ORE used earlier
this year.
SAREX II is to be a packet-radio package consisting of a flight-
hardened TAPR TNC 2 coupled to a Radio Shack Model-100 lap-top
computer and the same Motorola "MX" series HT used on previous
Amateur Radio shuttle flights.
We are striving, pending approval from NASA, to have this
hardware carried by Ron Parise, WA4SIR, when he flies on mission
61-E taking off March 6, 1986. The crew working on hardware and
software to make this happen are located in Maryland, Arizona,
Florida, Texas, Arizona and Iowa.
We now have prototype SAREX II software operating on 145.05 in
the Balto/Wash area under the call W3IWI-5. It is under test to
see if local users can make it croak! It has several unique
features:
ROBOT -- This is an automatic QSO machine that will work you and
assign you a unique serial number (in hex) for your QSO, and then
disconnect.
WORKED beacon -- If you successfully complete a QSO, your call
and serial number will appear at the top of the "WORKED" beacon
list. For local testing this (and other) beacons are being sent
every 15 minutes. In flight they will be repeated every 15
seconds or so.
HEARD beacon -- This beacon begins with a beacon sequence number
(to help piece the log together in flight) and lists the calls
heard most recently.
A normal beacon (currently addressed to SAREX II) is also used to
send a brief ( up to 120 bytes ) information packet.
A "meta-beacon" is also available (but is currently turned off)
to send up to 1.7 kbytes (7 * 255 bytes) of information. It is
planned that this feature will be used in flight to downlink a
mission status bulletin every couple of minutes or so.
These features have been designed to permit a large number of
packeteers to experience the thrill of space communications even
if WA4SIR is not personally available.
During the mission, some time will be reserved for special packet
tests including an orbital demo of store-and-forward
communications (a la PACSAT); software to support this special
mode is to be housed in the Model 100.
The ROBOT supports multiple QSO's simultaneously. Balto/Wash
users are invited to become abusers and to try to crash the test
software. Gang up on W3IWI-5. Lambaste it with simultaneous
packets. Try to make it croak. Make my day!!! Meanwhile, W3IWI-5
will also continue to serve as a local coverage digipeater from
its location at NASA/Goddard in Greenbelt, Maryland.
Reports on how it works will be appreciated. Especially solicited
are bug reports which should contain as much info as possible on
what happened. It's a lot easier to fix it on the ground than
when it is flying in orbit!"
From W3IWI
MFJ Announces TNC
MFJ has announced a TNC 2-type packet controller to be available
to the general public in February of 1986. Suggested retail
price for the wired and tested unit is $129.95!
Via HamNet
ARRL DIGITAL COMMITTEE MEETING
The ARRL Ad Hoc Committee on Amateur Radio Digital Communications
held a meeting in Newington, CT, on December 7th and 8th. Among
topics discussed were:
o Networking
o Congestion on the frequencies
o Preparation for Orlando Hamcation
o HF Packet Radio
o Digital radios
More information on the meeting will be printed in the next issue
of Gateway.
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