Annual APRS Golden Packet Event
& Scouting Operation ON-TARGET 2012

Bob Bruninga, WB4APR@amsat.org, Annapolis, MD

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AT Trail EMAIL Group! Please join the AT-Golden-Packet Yahoo group above now. It is used for planning and real-time comms for Ham Radio activities on the AT. For the Pacific and Western ON-Target Groups , see the PCT web page.

2014 Planning: Have not started updating each of the 15 pages, but so far have these committments (and probably missed a few emails, so remind me again if you are committed this year.

  • MtKatahdyn . . - uncomitted for 2014
  • Sugarloaf . . . .- uncommitted for 2014
  • MtWashington - uncommitted for 2014
  • MtEquinox . . . - uncommitted for 2014
  • Greylock . . . . - uncommitted for 2014
  • Sams-Point. . . - N2FMC, Dwight
  • Camelback. . . - uncommitted for 2014
  • GD Hill, PA . . - WB4APR Bob Bruninga
  • Northern VA . - KX4O John Huggins
  • MDmountains. - uncommitted for 2014
  • APpleOrchrd . - uncommitted for 2014
  • Roan Mtn . . . . - uncommitted for 2014
  • Clingman's. . . . - K4AEC(was KG4GPJ) Larry Ford
  • Springer . . . . . - Empty for 2014

    2013 Preliminary Report: 20 July 2013 we had all 15 mountain peaks manned including Canadians on Mt Carrelton in New Brunswick. New this year was the NH Relay location using Mt Equinox. The Northeast had some bad weather with Tim getting pretty well drenched up on Katahdyn. Very quickly most of the Northeast could all see packets from Sams Point (10) to Katahdyn. And similarly down South, most stations could see each other except for Springer Mtn which was also impacted by rain and only got out one packet. Clingman's also had heavy rain. Camelback seemed to have a deaf receiver on 2 meters and never heard any packets from anyone and so the chain was pretty well broken in the middle. Maryland Mountain also had severe VHF RX problems but corrected it by swapping Band A/B on his D710. After action review also revealed that AO Mountain relayed very few packets too, revealing a problem with Receiving, since its own transmitted packet were well received elseqhere. Here is a summary Excel table showing the RF parameters in each link. Send updates if you have them.

    The planning for 2013 is all on this spread sheet.

    Golden Packet and Operation ON-Target combined in 2012:. This year the Golden Packet (APRS) event was combined with Scouting's OPERATION ON TARGET event. On-Target is an annual Ham / Scouting event using MIRRORS and HAM radio to communicate from mountain top to mountain top. Out west there are may dozens of active troops doing OT, but are just beginning to apply APRS to their event, and conversly, back east we do the APRS Golden Packet from the Mountain tops but this year will add signal mirrors to help Eastern Scouts participate! See map.

    2012 SUCCESS! (94%) Appalachain Mountain Golden Packet!: We got all mountain tops manned and had successful links from Alabama/Georgia to Masachussetts and from New Hempshire to Maine, but had one break in the chain in NH. Here are the 15 east coast mountain pages links below. which will be updated with results as they come in. Click to see Success Log. Eastern OT was a washout with overcast conditions everywhere. See 2012 graphic.

    - - Operating Station. . . . . . Report Distance . . . . Other End

  • Lookout Mountain-1. . . . 2013 . . 85 miles to . . . Clingman's Dome, Sawnee Mtn & Huntsville
  • Springer Mountain-1. . . . 2013 . . 75 miles to . . . Clingman's Dome, Sawnee Mtn & Huntsville
  • Clingmans Dome-2 . . . . . 2013 . . 89 miles to . . . Roan Mountain.
  • Roan Mountain-3 . . . . . . 2013 . . 72 miles to . . . Comers Rock.
  • Comer's Rock-4 . . . . . . . 2013 . . 103 miles to . . Apple Orchard Mountain
  • Apple Orchard Mtn-5. . . 2013 . . 111 miles to . . Stony Man Mountain,
  • Stony Man Mountain-6 . 2013 . . 70 miles to . . . Maryland Mountains,
  • Maryland Mountains-7 . 2013 . . 70 miles to . . . Governor Dick Hill info,
  • Governor Dick Hill-8 . . . 2013 . . 78 miles to . . . Camelback(Big Pocono SP) or 120mi to Highpoint
  • Camelback Mountain-9 . 2013 . . 97 miles to . . . Sam's Point,
  • Sam's Point, NY-10. . . . . 2013 . . 61 miles to . . . Mount Greylock. Tried Highpoint, NJ in 2011
  • Mount Greylock-11 . . . . 2013 . . 48 miles to . . . Mount Equinox in NH (not avail in 2011/12)
  • Mount Equinox link-12. . 2013 . . 100 miles to . . Mt Washington.
  • Mount Washington-13 . . 2013 . . 102? miles to . Sugarloaf.
  • Sugarloaf-14 . . . . . . . . . . 2013 . . 61? miles to . . Mount Katahdin-15.
  • Mount Katahdin-15 . . . . 2013 . . DONE!!!!!

    July 2011 -REPORT! On July 24, 2011 we manned all 15 mountain tops from Maine to Georgia. This was the first year with someone on Katahdin, Tim, KA1YBS! (see photo right). Please see the 2011 Site List and individual team info on the links above. Click for the summary 2011 graphic. Yours-truely at GD-Hill somehow did not have UIFLOOD enabled for the first hour or so before some of the other stations were headed downhill. But the chains to each end from the middle seemed to be in place, though weak in New England sites. See the 2010 report, the 2010 map and the 2009 Report).

    USA Long Mountain Chains and Linear Trails!: Not only the Appalachian Team (this page) and the Pacific Coast Team, but any other long linear trail or mountain systems are welcome to participate. There are also opportunities on the other 50,000 miles of national trails including some possible alternate paths around the smokies and through New Jersey.

    North Country Trail: This year 2012, there is a new team going to activate the North Country Trail which runs through Michigan near White Cloud MI. Contact Jeff Sell K8OE or Mike McKay KD8DIB.

    The GOLDEN PACKET Event is the 3rd Saturday in July 2012: For the last 30 years, Packet Radio just ain't got no respect at the national Field Day events, so we have begun our own outdoors VHF packet radio field event! To make it more exciting we have joined with Scouting's Operation On-Target to attempt to activate all the long national mountain chains including the Pacific Crest Trail above left. Or even the Continental Divide, or New Orleans to Chicago, or Texas to the Dekato's or Lewis and Clark's National trail. Utah and Idaho are big players in the ON-TARGET exercise. We need to get enough HamRadio internet-junkies out of their shacks.

    To volunteer as a team leader for one of the other trails or Mountains, contact wb4apr at amsat dot org and join the YAHOO Group above.

    Goals: This year we are combining our annual amateur packet radio Golden Packet APRS communications event with the annual Scout Operation ON TARGET mirror and Ham radio commmunications event on Saturday 21 July. Our APRS Golden Packet event consists of APRS individuals on very high and widely separate peaks from Georgia to Maine or San Diego to Seattle or New Mexico to Montanna to attempt to relay text messages from hikers using hand-held radios the 2000 mile length of the Appalachain, Pacific Crest, Continental Divide or other long National mountain trails. Of course, this is to be a no impact Leave-No-Trace communications test of a few individuals at each relay point to support possible other hikers equipped with APRS ham radios along the trail. APRS normally does not do long haul RF, due to the omni-directional flooding of packets which causes QRM. But for LINEAR trails, there are NO dupes to worry about, and long haul along a trail is a great demo of emergency point-to-point communications.

    Bring a big Mirror. . . Tell scouts in your area to look for your flashes!
    Op - ON-TARGET:... See present On Target Site map.
    RF LINKS: . . . . . . . . See RF links for 2011
    RF PATHS: . . . . . . . . See RF analysis 2010 developed by John Huggins KX4O.
    SITE DETAILS: . . . . See individual links below for each mountain
    CHECKLIST: . . . . . . A comms coordination checklist has been prepared.
    D700 SETUP:. . . . . . . Settings for the D700 digipeater. (needs PC on comm port)
    D710 SETUP:. . . . . . . Settings for the D710 digipeater. (can do from front panel)
    D72 SETUP:. . . . . . . . Settings for the TH-D72 HT digipeater. (can do from front panel)
    VX8R SETUP:. . . . . . Setting the Yaesu VX8R HT for On-Target (can't digipeat)
    KPC3+ SETUP:. . . . . Settings for the KPC3+ TNC (though not recommended).

    PURPOSE: To find suitable, easy-to-reach sites which can be activated easily for potential backup emergency communications links across the USA. Amateur Radio has long been known to provide backup communications capability to public service agencies when needed. We will demonstrate our ability to communicate positions and messages along the length of the Appalachians or Pacific Mountains. Normally considered a 2000 mile hike, the Appalachian RF path is on the order of only 1200 miles and we hope to do this in only 14 hops. But additional Secondary Link Stations can also participate after the initial end-to-end tests are successful.

    WHEN: Saturday afternoon 21 July 2012 (not sunday as before), a date chosen to coincide with the Scouts Operation On-Target exercise. It also happens to be the annual CQ World Wide VHF Contest so there should be lots of HAMS on the Mountain Tops. The Operation ON-TARGET event lasts from 1100 to 1400 LOCAL TIME and the CQ contest begins at 1800z (also 1400 EDT). So we will do the Golden Packet tests along side the On-target times all the way up to the CQ contest. For the Appalachin attempt, this means we have from 11 AM to 2 PM to get our packets working. The PLAN for the 21 July Appalachian Trail Golden Packet experiment is (other mountain chains are welcome to make their own schedules):

  • 0800 to 1000 Set up (coordinate on your PUBLISHED local repeater, and APRS on 144.39, and ANSRVR)
  • 1000 to 1100 Station checkouts (voice with adjacent nodes on 445.925 (no tone), messages via HOP2-2 or so)
  • 1100 to 1300 Golden packet attempts on 144.34 MHz from both ends only (using HOP7-7,HOP7-7 paths)
  • 1300 to 1400 DIGIPEATER Site-to-site messaging only (using HOP7-7,HOP7-7 paths) on 144.34
  • 1400 to 1500 All other TRAIL hikers and DIGIPEATER stations (CQ contest begins)
  • 1500 to 1600 Any other APRS or packet stations in range
  • 1600 to 2000 Tear down and go home (Cease operations on 144.34).

    Permissions!: This is not a park event! All park and trail authorities have special event application fees as much as $100 each, so it must be very clear to even the casual observer that this is NOT a park event . Although ham radio operators have traditionally used the term event to describe a convergence of activity on-the-air, this is not a park event. That is why we have a designated leader at each site to organize any participation without triggering park concern. For 2009 on the AT we luckally got the OK of the ATC Ranger but had to do a lot of explaining to insure the low impact of our plans. One team made the mistake of trying to get an event approval and nearly got denied access to the park. See our attempted letter to try to recover. There is no law or rule against operating an Amateur Radio mobile in a park, just follow all existing rules and remain no-impact and LEAVE-NO-TRACE: Stay well below the threshold that would trigger concern by any National, State, or local park authority and require copious red-tape.

    VOLUNTEERS: We need volunteers for the planned peaks, plus any hikers that want to participate. Due to the criticality of each site to the whole event, it is a requirement to have backup people, and hardware. Also, an extra person to answer any questions of any bystanders. Details for each site are in the links below. Most day hikers are really into GPS, so why not APRS too? . To sign up as a volunteer, please contact wb4apr at amsat dot org or better, contact the individuals and team leaders for each team on each of the station web pages below. Due to the height of these stations, probably half of all east cost hams can monitor the test in the shaded yellow area shown at right.

    APRS BACKGROUND: Although the Global APRS network provides full coverage along the Appalachians on the USA APRS channel of 144.39 MHz, it is linked globally via the internet and so it is impossible to demonstrate long distance communications on RF only. Plus it is RF saturated. Long haul RF communications is not possible nor encouraged due to congestion. . Therefore, this test will use a special uncongested frequency (144.34) just for this one day. Using amateur radio from mountian peaks is part of the peak2peak and SOTA projects, but to reduce the risk of RF congestion, this test is planned to avoid any VHF contest weekend.

    SIGNIFICANT APRS CHARACTERISTICS FOR THIS TEST:

  • 1) Trail stations will use the short path HOP7-7,HOP7-7 for all traffic
  • 2) Trail stations may use the traceable TEMPn-N for short tests
  • 3) Stations should be able to see all adjacent nodes in both directions
  • 4) Being linear links, there will be few dupes and little QRM.
  • 5) D700/710 or D72's are required for consistent TEMPn-N and HOPn-N digi's.

    The reason for the radio specific requirement is due to the elimination of ALL potential set-up, configuration, and interfacing issues. See below.

    STATION AND ROUTE PLANNING: For maximum range between hops, the best path for all trails from Georgia to Maine or San Diego to Seattle, ZIG/ZAGs as shown on the above maps rather than trying to shoot straight along the ridge. The height-above-average-terrain between the peaks along the trail ridge is significanly less than across valleys and drastically limits line of sight distances. . But zig/zagging from the peaks to adjacent mountain ranges and back across valleys, takes advantage of thousands of feet difference in heights above average terrain and allows us to make much greater distances in fewer hops.

    GOOGLE EARTH DOES RAY TRACING! (sort of)... See the views created in The free Google Earth to see the RF paths and ground clearance. (anyone can do this). You can also get these views with APRS stations actually plotted on them on both The OpenAPRS and APRS.fi sites. . If you zoom into any of the links below, you can see these 3D views including the heights of The rays.

    SOUTHERN HALF OF THE APPALACHIANS ON GOOGLE EARTH. SEE BELOW:

    Using this Google Earth Technique, we nailed down Apple Orchard Mountain along the Blue Ridge Parkway with excellent views both north and south as a solid location due to its popularity with VHF Contesters. Also it has three FM repeaters on 146.685, 442.65, 443.3 MHz with PL 100 making path testing easy. From there we explored all options north and south. the view below shows all the possible routes from Springer Mountain in Georgia to Apple Orchard Mountain through the southern Appalachians.

    WESTERN I-81 Valley Route: The western route is shown in red via 4 hops. You can see each link in The 4 links below:

  • Springer Mountain-1. . . . 75 miles to . . . Clingman's Dome.
  • Clingmans Dome-2 . . . . . 89 miles to . . . Roan Mountain.
  • Roan Mountain-3 . . . . . . 72 miles to . . . Comers Rock.
  • Comer's Rock-4 . . . . . . 103 miles to . . . Apple Orchard Mountain

    We had looked at trying to make a 2 hop path from Clingman's to Apple Orchard via Rogers Mountain, (see path) but it was very marginal and Mount Rogers is all tree covered with no drive-up access. The adjacent Whitetop Mountain has good access and is popular with VHF contesters but is blocked to AO by Mount Rogers. The best path zig's across the I-81 valley to White Rock Cliff on Little Sluce Mountain on the Virginia and West Virginia line and then on to the Maryland mountains. These links all the way to Mount Katahdin are listed below.

  • Apple Orchard Mountain-5 . . 111 miles to . . . White Rock Cliff,
  • White Rock Cliff-6. . . . . . . . . . 70 miles to . . . Maryland Mountains,
  • Maryland Mountains-7 . . . . . . 70 miles to . . . Governor Dick Hill info,
  • Governor Dick Hill-8. . . . . . . . 78 miles to . . . Camelback Mtn (Big Pocono SP) or 120 mi to Highpoint, NJ (1 hop bypass)
  • Camelback Mountain-9. . . . . . 97 miles to . . . Sam's Point,
  • Highpoint, NJ. . . . . . . . . . . . . 120 miles to . . . Greylock, MA in one hop (alternate 1 hop bypass)
  • Sam's Point, NY-10 . . . . . . . . . 61 miles to . . . Mount Greylock.
  • Mount Greylock-11. . . . . . . . . 48 miles to . . . N1NCI-3 in New Hampshire
  • N1NCI-3 NH link-12. . . . . . . 100 miles to . . . Mt Washington.
  • Mount Washington-13 . . . . . . 102? miles to . . . Maine-Relay (KQ1L-6),.
  • Maine-Relay (KQ1L-6)-14 . . . 61? miles to . . . Mount Katahdin-15.


    EASTERN PATH ALTERNATE: From Georgia, we found a possible 4 hop path around to the east starting with a 68 mile path from Springer Mountain to Whiteside Mountain in North Carolina, then on to Sugarloaf, and to Pilot Mountain and on to AO as shown below. But we never got any volunteers along this route. (see route)

    Whiteside Mountain to Sugarloaf Mountain . . . 54 miles
    Sugarloaf Mountain to Pilot Mountain. . . . . . . 120 miles
    Pilot Mountain to Apple Orchard Mtn. . . . . . . . 98 miles

    But again, we do not know if those peaks are accessible? But we could activate this alternate path as well and simply include a DWAIT on the eastern path. This would slightly delay those packets and avoid any collisions with the other I-81 path. And it could double our reliability!

    STATION CALLSIGNS-SSID's: Since there are 15 stations, we used the 15 SSID's in sequence for the convenience of knowing the relationships between sites along the way. Specific callsigns have been assigned so that messaging can occur in the blind. Please see the callsign list. The sequence is South to North which is the usual direction of through-hikers who begin the treck in the spring in Georgia and hope to end by the Fall in Maine.

    STATION TEXT: Initially, each station sets his position text to include his FCC call and his estimated event-end-time. Something like WB4APR till 1400EDT (meaning 1400 Eastern Daylight Time). But as he begins to see other stations, he can show what he is seeing by including their X# in his text. Example: WB4APR till 1400 QSL:12345689ABC which means WB4APR can see other stations as far south as 1 and as far north as 12 ("C" in Hex) and all stations in between.

    FREQUENCY - Packet and UHF coordination: Finding a clear frequency for the 4 hour event is a severe problem. Since the duration of this event is about the same as the duration of a Balloon flight, and just as exciting, we asked the ATV Balloonests if we could operate on 144.34. For simplex voice coordination, the national APRS FM simplex channel of 445.925 is used. In addition, parallel operation of a second APRS station on the national 144.39 can also be used for end-to-end coordination. The below diagrams show how a TM-D7 dual band APRS radio can serve all functions of Digipeater, Text Messagingand Voice coordination. While a D7 HT can be used for the 144.39 normal APRS opertaion.

    ECHOLINK/IRLP COORDINATION: Since this is a comms exercise, we should test our ability to establish voice communications with Echolink or IRLP voice links. Each site can call into a conference node set up for this event. To find the nearest EchoLink node please see the Echolink node finder. We can use this for end-to-end overall coordination from 11 AM to noon or onward. Think of it! End-to-end Voice, end-to-end APRS messaging (on 144.39 via IGates) and hopefully end-to-end APRS on RF alone for the test. See these IRLP nodes along the trail IRLP Map South, and IRLP Map North.

    For the 2009 conference node, WB3GXW has offered his *WASHDC* node, number 6154 for this test. Just connect in at 11 AM and join in (AT Stations only).

    POSITION PACKET RATES: The standard APRS rate for Tactical Operations is once per 10 minutes. This gives good update latency while keeping background channel loading low. Each digi will hear two other digis direct, but will hear up to 14 other station position reports. With these statistics the channel (as heard at each digi) will be blocked for 3 seconds each or 45 seconds total in 10 minutes or about 8%. . This is close to half of the channel ALOHA capacity and leaves plenty of room for the messages. Hopefully Mic-E format will be used for efficiency.

    MESSAGE PACKET RATES: The other half of ALOHA channel capacity is for message packets. Using the above logic, Stations should not average a higher message rate than once every 10 minutes if all 15 stations are operational. During set-up and throughout the test, end-to-end APRS coordination is easy on 144.39 either normal operation or via the ANSRVR with messages to CQ AT CQ AT. (see ANSRVR).

    DIGIPEATER BATTERY POWER: The Mountain top Digipeaters consist of a D700/D710, a mast as required to clear the trees, and a power source. The mimimum test is 3 hours long, but the optional phases can last up to a total of 5 hours, so ample AMP-Hr capacity should be considered. The D700/710 draws about .7 amps on receive and about say 4.5 amps on TX (medium power 10W). Under normal operation, the APRS ALOHA channel can support up to about 20% load so the average digipeater power demand will be about .2 * 4.5A +.7A or about 1.6 Amps per hour. A good plan might one 7 AH battery for the event, or two 4 AH batteries, replacing one toward the end as it dies gives a good indication of battry life remaining (the spare). We have found enough clouds or rain every year to make it too risky to depend on solar power. (a 1 Amp-Hr battery and a 1.5 amp solar panel as shown).

    We are requesting that only D700 or D710 radios be used as the digipeater, since there can be so many different ways for a TNC/radio combo to be tuned or set up wrong. Listening to packets on the air, MOST have poor audio, tone, levels, tone inbalance unknown pre-and-de emphasis and deviation settings adding up to 20 dB or more in performance loss. We can eliminate these variables by just using D700's that at least were all set for optimum at the factory, and provide reliable packet operation down to a very good 0.3 uV (-117 dBm).

    DIGI SETTINGS: Each digi along The trail will be set to support traceable TEMPn-N packets and the shorter non-traceable HOPn-N path. The two settings are: "UITRACE TEMP" and "UIFLOOD HOP,ID" or similar depending on exact TNC used. Once these settings are in the D700/710, they can actually remain there forever since we want all D700/710's always to be able to at least support the come-as-you-are TEMPn-N backup system. All D700/710's are supposed to be configured with the TEMPn-N support by default for emergency backup communications at any time. TEMPn-N is great for omni-directional temporary communications for special events like Field Day. Here we cannot afford the bulk, however, of the long trace packets using TEMPn-N, so we are using HOP7-7 which should only ID the last digi in each packet.

    PACKET PATHS: All packets will use the HOP7-7,HOP7-7 path so that packets will go the length of the trail. Using this non-traceable path keeps the packets short. But to resolve any anomolies, the Traceable TEMPn-N paths are also possible for short tests, but these packets grow by 7 bytes at each hop and should be avoided most of the time. No one knows what will happen beyond that.

    MESSAGE FORMATS: For the official long haul Golden Packets that you want everyone to see, use only BULLETINS (BLN#xxxxx). This eliminates ACKS and QRM, yet lets everyone read the mail. To indicate a specific recepient, squeeze their identifier into the available optional 5 bytes xxxxx, but otherwise the xxxxx is not needed. Stations with D700's must read and delete incoming messages to make sure to keep room for more incoming messages. D710's can hold as many as 100 unread messages. Keep a paper log if you are not using a PC APRS as well.

    GOLDEN PACKET TRACING: We only use HOPn-N paths instead of TEMPn-N paths. You can see how these packets would get very long, if TEMP7-7 Tracing was used. The packet can only go 7 hops and would arrive as SGRLOF-14,MTWASH-13,N1CNA-12,GRYLCK-11,SAMSPT-10,CMLBCK-9,GDHILL-8,TEMP7*

    But using HOP7-7,HOP7-7 it can go 14 hops and arrive simply as: MDMTN-7,HOP7,MAINE-14,HOP7*. This shows that it took 7 hops to get to Maryland Mountains and then 7 more hops to the MAINE RELAY site.

    DUAL SYSTEMS: Each participating digipeater site station should operate with two APRS stations.

  • Use the main high power station (D700/D710) as the digipeater. It can also be used for MESSAGES via HOP7-7,HOP7-7.
  • Use an HT or other APRS station on 144.39 for all other information and chatter either normally or via the ANSRVR.

    2-WAY IGATES PROHIBITED! It would be a disaster if someone brought up a 2-way IGate on the test frequency. But, on the other hand, having a SINGLE monitor-only Igate at each end and in the middle might let the world watch-in. But again, this is playing with fire, and a missconfigured IGate could spoil the entire event.

    HARPERS FERRY and TRAIL CONFERENCE DEMO: Another possible volunteer need would be to set up a Ham Radio demo table near the Appalachian Trail Conservancy Headquarters in Harpers Ferry on the test day to demonstrate the event and another possible demo at the at the Biennial Appalachian Trail Festivals to promote Amateur Radio to the assembled thousands of hikers attending the festrival. Other low-key demonstration stations at public areas along the AT are also be welcome.

    Is it LIVE or is it Google?: The next two images are the Google View and an actual photo provided by W4WWQ. The ray traced is towards Mt Rogers.


    the ray shown is to Rogers Mountain

    See slightly more to The SW.. and Hogback to Quirauk

    OTHER REFERENCES MAYBE:

  • Mountain Peaks and Summit Names Create Simulated Views from Peaks
  • Mountain Peaks, Summits, and High Points
  • LAT/LONGS of peaks
  • List of peaks on The AT from Jorge, KI4SGU
  • List of Towns near The AT from Jorge, KI4SGU
  • List of access roads on The AT from Bob, WB4APR
  • see VA trail map.
  • link N. to Tea Mtn.

    Bob, WB4APR

    See my other GENERAL page on APRS applications and Ideas on The AT


    Return to The APRS HOMEPAGE or SiteMap.