MARCAN APRS: Getting StartedHere is some basic information on Getting Started with APRS.
BASE STATION: If you've been involved with Packet Radio before, then using APRS at home will be easy. It uses all the same equipment, just new software. You will need the following for an APRS fixed-station using RF. (If you want to run APRS at home but Internet only, skip to part 2.) 1. Amateur Radio VHF station consisting of: 1.1 VHF (2m) radio that can receive and transmit on 144.390 mhz with a power output of about 10w. 1.2 VHF (2m) outside antenna to work local stations and nodes. 1.3 Packet tnc same as used with Packet Radio. (MFJ1270 series, Tiny-II, KPC3, etc.) 2. Computer (or Laptop). PC, Mac or Linux OS will run APRS client software. 3. APRS Client Software. The most popular APRS software is UI-View for PC. It is available at: UI-VIEW Site You can get sample maps from my site at: MARCAN UI-VIEW Maps I also recommend APRSISCE in Windows: APRSISCE Here is a full list of client software: APRS Client Software For Linux or MAC users, there is Xastir. - The APRS client can get it's data from either an RF station (part-1) and/or an Internet feed from an APRS server. TOP
MOBILE APRS: An APRS mobile can be either of 2 types. A full 2-way station as in part 1-3 above or just a 'Tracker'. Most APRS mobiles will be using the 'Tracker' since it requires no user interaction or displays. A 'Tracker' is a tnc, similar to item 1.3 but specifically made for APRS. This type of tnc is normally transmit only. There is provision to 'detect' on-air signals but it does not decode them. The purpose here is to just transmit data about the mobile's location. So here again all items in part-1 will be needed. The transceiver can be an old surplus radio, xtal-controlled or an HT with at least 3 watts of output. 1.3 TNC as mentioned, a 'Tracker' tnc like the OpenTracker. Available at: Argent Data Systems A similar mobile tracker tnc the TinyTrak which is available at: Byonics TinyTrak The Trackers have software built-in so item 3 is not needed. However, you do need an additional item for the mobile, the GPS. 4. GPS - must have serial (RS232) output of NMEA data (4800b) You can use almost any GPS that has a serial output, not USB. However, most people will want a cheap & simple GPS setup with no need for a display. I recommend the Deluo WAAS, available at: GPS receivers This GPS runs on +5v and can be powered directly from the OpenTracker tnc. The configuration of the tracking is done with a provided PC program using its serial port. Sample configuration settings are: OpenTracker Config Screen TOP
APRS SETTINGS: Some notes about common tnc settings and standards. 1. Beacon times - Mobile If you look at the OpenTracker Config Screen for example, you will see two settings that affect beacon times. This tracker uses Smart Beaconing to vary the beacon rate between every 1200 seconds (20mins) when the vehicle speed is 10kms or less, up to a maximum rate of every 90 seconds when moving at 94kmh or more. For tncs that have only a timed beacon rate like the D7/D700, its imperative that this rate be adjusted so as not to cause unnecessary transmissions while not in motion. A fixed rate of 2mins while in motion and 20mins while stopped is reasonable. 2. Beacon times - Fixed station For a fixed station we recommend one universal rate of every 20 mins. This applies to all fixed stations, be they home, node, gate, wx, whatever. 3. Beacon Paths - Mobile/Fixed In conjunction with the beacon rate is the recommended beacon path. For fixed stations one standard path is used but mobiles have two options: 3.1 WIDE3-3 This is the universal beacon path that is used by most mobiles, and all fixed stations in this region.(Home, nodes, gates, wx, etc) WIDE3-3 is processed by all UIDIGI nodes in our network to give up to 3 hops of coverage. *** Note some areas may recommend WIDE2-2, (2 hops) where activity is high or an Igate is near. 3.2 WIDE1-1,WIDE2-2 This path has two settings, the first will take advantage of any home stations set for local digipeating (WIDE1-1). Since all our UIDIGI nodes respond to WIDEn-n, they will digipeat on either part of this path up to the 3 hops.(The actual number of home stations set for proper digipeating is unknown but expected to be very few, yet using this setting does not detract from normal digipeating through network nodes.) *** Note some areas may recommend WIDE1-1,WIDE2-1, (2 hops) where activity is high or an Igate is near. 4. SSID The SSID is normally used to identify the type of APRS station. For example, my home station might use the tnc callsign of VE1AIC-0 (The SSID of 0 does not display). While my mobile station would use VE1AIC-9. Having different SSID's also allows the two stations to be active at the same time (on the same channel). It is imperative that only legal callsigns be used on RF transmissions. Here are some standard SSID's used in our area: -0 Home, Node, fixed station. (remember the '0' does not show) -1 Gateway, Server, Multiple nodes -2,3 Multiple fixed stations -4 WX Station -5,6 various -7 Kenwood D7, or D700 radios -8 various -9 MOBILES (This is the standard SSID for mobile APRS) -10->15 various 5. OBJECT BEACONING & Internet->RF: Beaconing of objects on RF should be limited to one or two objects per station, at a rate of no less than 20 mins, and a path of direct or a maximum of 1 hop if necessary (NOT 3 hops). Exceptions may be made for special events over a short time period. Similary, gating APRS packets from INTERNET to RF should also be controlled with the same 20min rate and direct path or 1 hop maximum. Also NO non-Amateur/APRS objects or packets should be gated onto RF. OTHER INFO: If you have questions you can get help from the Yahoo APRS group. APRS was developed by Bob Bruninga, WB4APR. APRS WIKI.
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