wheatley@inuxi.UUCP (Steven Wheatley) (11/24/85)
Gateway: The ARRL Packet-Radio Newsletter
Volume 2, Issue 7
November 22, 1985
Published by:
ARRL
225 Main Street
Newington, CT 06111
Editor:
Ed Raso, WA2FTC
FROM THE EDITOR
As reported in the last issue, Jeff Ward, K8KA is no longer the editor of
Gateway. Instead, Jeff has decided to pursue a unique opportunity with the
UoSat project in England. I know all of you appreciate the superb job Jeff
has done editing Gateway, and will join me in wishing Jeff success with his
new endeavor -- good luck Jeff.
As the new editor of Gateway, I will continue to report the latest news and
developments taking place in the packet-radio community. Remember, much of
the information contained in these pages comes from our readers. If
Gateway is to continue to report the latest news that shapes packet-radio,
it needs your input and support. If you have news that you would like to
see included in Gateway, mail it to:
ARRL
Gateway Editor
225 Main St.
Newington, CT 06111
You may also send news electronically via CompuServe to ID: 72747,3207 or
via American People Link (PLINK) to ID: ED*WA2FTC. I hope you will
continue to enjoy Gateway.
Ed Raso, WA2FTC
KENTUCKY PACKET ASSOCIATION
Several local radio clubs in Kentucky have joined together to form a state-
wide packet organization. The state will be divided into several regions,
with each region represented by its own chapter. The purpose of the
organization is to coordinate packet activity and disseminate information
throughout the state. The organization plans to publish its first
quarterly newsletter later this month. For more information, contact:
Dan Hund, KB4CF
3444 Merrick Dr.
Lexington, KY 40502
From KE4NS
CALIFORNIA PACKET
On November 3, 1985, the silence on 145.05 Mhz in the southern half of
California was broken with the installation of KB6C-1 on Frasier Peak (8000
ft). The site covers the greater L.A. area, San Diego to the south and
Visalia to the north. KB6C-1, along with the existing site of WB6AIE-1
high in the Sierra Mountains, provides coverage from San Diego in the south
to Modesto in the North. Plans are in the works to establish a site
further north on 145.05 that will extend the coverage near the Oregon
border. This system should give users an alternate path while providing
the state with a three-hop network for use during times of emergency.
A mailbox is available in Fresno (middle of the network) operating under
the call of WB6AIE. It is hoped that the central location of the mailbox
will provide two-hop access to most users. This system is identical to the
coastal 145.01 system operated by W6IXU. The 145.05 system runs north and
south in the middle of the state, while the 145.01 system runs along the
cost.
Comments or suggestions should be forwarded to Dennis, KB6C or Jerry,
WB6AIE via the WB6AIE mailbox.
From WB6AIE
PACKET AND SET
On October 19, 1985, five north Texas stations participated in the
Simulated Emergency Test (SET). Two local digipeaters, KC5LW-1 and N5EG,
proved essential for passing traffic. The method of traffic handling was
exclusively off-line message editing and preparation in accordance with
ARRL radiogram format. All messages were transmitted as files which
reduced the transmit time per message to less then 15 seconds.
A test of the prototype PACGRAM software (Packet Status Register, March
1985) was conducted. One PACGRAM was successfully received at the Regional
DPS office. This style of semi-automated message handling shows great
promise for emergency service activities. Overall, we passed as much, or
more traffic than the voice operators, and from a much larger area.
Participating stations were: W0DRO, KB5F, WB5IZL, WB5QLD and WA5MWD.
From WA5MWD
KANTRONICS FIRMWARE UPDATE
Kantronics has released a new version of their TNC firmware. The update
costs $10.00 and may be ordered by phone. New features include: 1) time
and date stamping 2) calls heard list 3) trace command, and 4) path shown
for repeaters.
Via HamNet
PTT MOD FOR TNC2 CORRECTION
W3IWI reports that the TNC2 PTT modification published in the Packet Status
Register and CTM has one error. The last sentence of the last paragraph
indicates that you can reverse the sense of the LED from bright=receive and
dim=xmit by attaching the 1k resistor to pin-9 of U14 instead of pin-
8...this is wrong.
The problem stems from the fact that U14 is used as part of the BBRAM logic
and is powered from the battery when the power is off. If you reverse the
sense, you will drive the battery current thru the LED and kill the
battery. The modification (dim on xmit) works fine and doesn't drain the
battery. When the power is off, pin-9 of U14 is low and no current flows
thru the LED.
Via DRNET, W3IWI
SAREX II
The SAREX II packet-radio experiment to be carried aboard Shuttle flight
STS-61E by Ron Parise, WA4SIR, has the potential for the greatest number of
two-way contacts of any shuttle experiment to date. Operating in robot or
monitor mode, the TNC has the capability of logging as many as ten calls
every ten seconds. The sheer volume of packet-radio stations (10,000) by
the March 1986 launch date precludes carrying any simple logging scheme on
board. Instead, log beacons will be transmitted from the TNC on the
downlink frequency for all stations to copy in real-time. Not only does
this method give real-time feedback to public demonstration stations, but
it also can be used to demonstrate the efficiency of the existing
terrestrial packet-radio network during post-flight data collection. By
collecting all log packets received on the ground into a database, a
complete log of all spacecraft packet activity can be constructed.
The purpose of this is to suggest an organized scheme and plan for the
forwarding of all log data via Amateur packet-radio or other electronic
mail into a central database. Because of the tremendous volume of reports
and the regional similarity of most received reports, data reduction should
be accomplished by regions and forwarded to a central point in a standard
format.
Since most local area networks (LAN) are served by at least one W0RLI BBS,
a first cut is to suggest that one station per BBS be designated to collect
log reports from his LAN in message format. This station will accumulate
individual messages into three Xerox 820 summary files: 1) a short file of
all stations submitting a log report, 2) a file of all HEARD reports, and
3) a file of all WORKED reports. (One set of files per day of SAREX II
packet operation). Each of these BBS files will be forwarded to a regional
SAREX II coordinator to eliminate all redundant data and prepare a regional
log. These logs will be submitted to Goddard ARC for final processing and
assembly. For ease of processing, all logs submitted should be word
processed by the originator into a specific format. An optimum solution
would be to have the shuttle TNC time stamp each beacon. Using this
method, only the exact beacon text string need be included in the collected
data from individual stations. The standard format will simplify the data
reduction algorithms significantly. These logs will be reduced into
regional databases showing a maximum of ten HEARD times and five QSO
numbers. Times will be in a six-digit serial UTC (HHMMSS) format. The QSO
log is a four-digit hex number allowing as many as 65,000 unique
assignments.
It is requested that regions select a single data reduction facility that
has the capability of reducing data from the Xerox 820 message file format
into IBM PC format for reduction using dBASE II. Regions can best be
defined by arbitrary groupings of packet activity such as: SOUTHNET,
EASTNET, GRAPES, MAPRC, NEPRA, CITS, etc. For more information, contact:
W3IWI
59 Southgate Ave.
Annapolis, MD 21401
Via DRNET
TNC2 UPDATE
A problem has cropped up on a very small number of TNC2 boards. The MF10
switched capacitor filter will latch-up to the positive +5 supply causing
the regulator to become very hot. To cure the problem, change C10 on the -
5V supply from 10uf to 47uf. If you experience any latch-up problems after
changing C10, please notify TAPR immediately. Given our results, I
strongly recommend all TNC2 owners institute this change.
From AD7I
NEW PACKET VENDOR
A new company, PacComm Packet Radio Systems, Inc., of Tampa, Florida has
announced the availability of its TNC-200 Terminal Node Controllers for
packet-radio applications. PacComm has been licensed by Tucson Amateur
Packet Radio (TAPR) to produce packet controllers based on the TNC2 design.
The hardware design is the latest TAPR Revision 2 printed circuit board.
The standard TNC-200 features 16 kbytes of RAM, 32 kbytes of EPROM, a CMOS
Z-80 processor and a long-life lithium battery. The unit is packaged in
the familiar extruded aluminum cabinet. The TNC-200 is available in
standard low-power CMOS or optional NMOS.
PacComm Packet Radio Systems is owned by Andy Demartini KC2FF and Gwyn
Reedy W1BEL both of whom are actively involved in FADCA, the Florida
Amateur Digital Communications Association. Gwyn Reedy is currently editor
of the FADCA>BEACON. For more information, contact:
PacComm Packet Radio Systems, Inc.
4040 W. Kennedy Blvd., Suite 620
Tampa, FL 33609
Via KC2FF
Packet Radio on the Move -- The Club Connection
(Fourth in a series by Steve Place, WB1EYI,
Manager, ARRL Volunteer Resources)
When we last left our hero, Pierre Packette, he was stuggling valiantly at
the podium, flailing the air with a large club in a selfless attempt to
save the townspeople from the evil clutches of Phil la Text . . . Ooops.
Sorry. Hallucinating. At times, the bi-weekly serial approach to planning
a club meeting gets a bit frustrating for me as well as for you. Thanks
for bearing with me so far.
At this point in your fledgling packet-radio club's first meeting, you've
made your guests feel welcome and have determined just what sort of critter
has shown up -- and what sort of task you're faced with. If your gang did
its pre-meeting promotional work well, you'll have a broad spectrum of
technical sophistication and experience before you. What's the next step?
Packet Radio Overview and Tutorial
You should decide among yourselves what sort of overview is most
appropriate based on your expertise and your audience's sophistication. A
few battle-scarred techniques, tested under full combat conditions,
however, will help you sustain a high level of interest.
* keep it light and keep it loose
* approach the introduction from the user's perspective and stay there
* don't get bogged down in technical detail
* impress them with the simplicity and ease of using packet radio, not
with your technical prowess
* use very simple, clearly sketched depictions of what a packet
"looks" like as well as diagrams of uncomplicated networks (well-
chosen graphics can create breakthroughs in understanding)
* have all such visual aids (including chalkboard, chalk, eraser and
handouts) ready before the meeting starts
* let them hear what a typical transmitted packet sounds like and gain
a sense of the typical time delays in routing a packet through a
number of stations
* leave the full-blown demonstration(s) for the next portion of the
meeting
Be prepared to answer cheerfully the ubiquitous inaugural-packet-radio-
club-meeting questions that are innocently and sincerely raised by people
who should nonetheless know better:
* What equipment do I need? (answer at the "black-box" level)
* How much will it cost me to get a packet station on the air? (be
honest; cover the options and tradeoffs briefly)
* Why bother with packet radio? I'm already using my computer on RTTY
and CW.
* What will joining this club do for me? What's it cost?
* Who sells this stuff? How hard is it to build? Do I have to build
it? Which brands are best?
Everyone has his own definition of what's best: the least expensive; the
most reliable; the most compatible/adaptable; or the model sporting the
flashiest chrome, brightest blinking lights, most awe-inspiring strap-
yourself-in-for-blastoff console and the cutest little baby shoes hanging
from the rearview mirror. Be honest. Talk from your own experience. And
whatever you do, if you don't know the answer to a question, simply admit
it, ask if any of the other club members can help and promise to get the
answer for everyone by the next meeting. Honor that promise.
When you get right down to the bottom line (final amp in ham radio
parlance?) the most effective tutorial overview of packet radio for a first
meeting is the simple, informal chat aimed at covering what it's all about
and why your guests should be interested. If you do it with a smile and
pace your explanations to meet their needs, you'll give them a taste of the
adventure, a desire to pursue their interest just a little further and a
belief that your club is heaven's answer to their feelings of technical
inadequacy. If I'm not mistaken, that sounds a little bit like the
objectives you wanted to achieve!
But don't stop there. You've cast the net with your welcome and chummed
the waters with your tutorial. No self-respecting packet-trawler Captain
would hoist anchor and set sail for port without first hauling in his
catch. Spark their interest with a hands-on demonstration; convince each
guest with carefully-tailored special working groups that packet radio is
the solution to his particular problem; give each guest a reason to show up
at the next meeting by assigning to each working group a small study on
which they are to report back to the club; and then make each guest want to
return by welcoming him into your club socially at a local bistro.
We'll help you chart a safe return course -- your main hold overflowing
with a fresh catch of packeteers -- in the next installment.
From WB1EYI
NTS Needs Packet
Ed Eklund, K6XI, responding to "Does NTS have to stand for Naturally
Troublesome System . . ." (in "Packet Radio and Warm Bodies," Gateway,
October 1, 1985, Vol. 2, No. 4), writes --
"Amateur Radio is a public service, 'particularly with respect to
providing emergency communications.' That does not mean just
being around to yell for help at chance encounters; it means
organized preparedness.
"We are unique among voluntary services in our potential for 'formal
written' traffic but unfortunately NTS is slow, inaccurate,
undependable and has insufficient capacity for emergency
communications.
"An increasingly sophisticated public is no longer awed by the
performance of amateur radio. A major effort might show that
amateur radio is indeed a public service and the biggest bang for
the buck would be to vastly improve NTS, something that is now
possible thanks to packet radio.
"Nationwide packet radio system linking mailboxes serving present
general participation nets could make NTS fast, accurate,
dependable and have sufficient capacity for emergencies. ARRL Hq
could plan a packet system, establish protocols and standards for
equipment and do massive promotion.
"Many veteran 'higher-echelon' operators would resent having their
positions eliminated and they have the clout through area staffs.
However, section net operators would like better service as it would
greatly increase volume and interest, but unfortunately they, the
main body of NTS, have no direct representation.
"The public, if asked, would wonder what took us so long. After
all, are we not said to be 'expert communicators on the cutting
edge of technology?'
From K6XI
REPRODUCTION OF GATEWAY MATERIAL
Material may be exerpted from Gateway without prior permission, provided
that the original contributor is credited and Gateway is identified as the
source.