On Fri, Oct 30, 2009 at 11:03 AM, Kevin Jensen <[email protected]> wrote:
> 1) 15 seconds only matters, if someone can hear my packets. Sure, if you are in the middle of no where, hundreds of miles from anyone on 144.390, this is true. You're not quite in that situation in West Haven. There are a LOT of stations within 20 miles of you. You are very probably being heard over that kind of range. Digipeaters with good HAAT will easily hear you over that distance. > That is still an issue, as they are not getting through for some reason. Getting through is a totally different issue than being heard. While it is true that you "won't get through" without being heard, the opposite is not true. You could very well be heard by MANY stations, but because of issues such as deviation misadjustment, you won't "get through". Being heard and being decoded are related but not equal. > Maybe 5 to 10 get through and are displayed on APRS.FI for the 20 > minute trip to work in the morning. Nothing else gets through. So, some stations are able to hear AND decode your packets. This tells us that for the most part everything is working on your setup... this could still indicate an improper deviation, low power output/bad SWR, or something like that causing problems. > The > packet frequency is not that busy. I can hear packets from several > other stations, and they all display on my Nuvi 350. The packet frequency is not that busy from your perspective. You can only hear the activity that is within simplex range of your station. Let's say that for arguement's sake that is a 20 mile radius around your vehicle. Digipeaters are usually located where they have a pretty good view of the area around them. Let's say a digipeater 10 miles away can hear an area with a 30 mile radius. That digipeater can hear everything you can, and a whole lot more. If there are stations within range of the digipeater that are sending packets at the same time you are, at best, one of the two stations are going to be heard by FM capture effect. Worst case, both packets are garbage. Now consider that neighboring digipeaters will usually be able to be heard by the local digipeater, even if they are further than 30 miles away simply due to the fact that the digis are up on high spots. Digipeaters are hubs of activity, repeating packets like crazy. They listen to all activity on the frequency, and only digipeat those packets asking for another hop. Packets that have paths that are used up are still heard, but not digipeated. This still takes up time on the digipeater even if it's not going to digipeat the signal. For you as a user in the digipeater area, it might sound like there's not a lot of activity, but for the digipeater, it might be another story. Try driving up on a hilltop nearby one day and have a listen to 144.390 for a while. See if it still sounds really quiet. > 2) Have tried setting SMART to ON with appropriate parameters (as > suggested here), and an INTERVAL of 2 minutes. With these settings, I > get two or three packets through on my 20 minute trip. Yes, because SmartBeaconing is going to send fewer packets than your 15 second interval. Throwing hundreds of baseballs at a dunk tank target gives you lots of opportunity to hit the target, but a couple well aimed baseballs that hit the target means your arm is not as sore at the end of the day. > 3) Do I have something wrong? Most likely... first culprit to look at is deviation, as it is a very common setting to have set wrong. > Does a packet contain all the last > several coordinate breadcrumb trails in it (several gps coordinate > sets that are stored over the last several minutes)? Or does a packet > only contain the last single coordinate set, for the moment? I think > the latter. You are correct. The packet only contains the current GPS information. Regular APRS does not do any buffering of information. APRS is a fire and forget protocol. There's no way for your station to know if the packets you are sending are being heard by anyone. > 4) I can hear the packets fine with my stand alone HT radio, with > APRS. They should like everyone elses packets. But maybe I do need > to adjust the volume settings (what is that command?) so that the > modulation is improved. Maybe I am undermodulating the packet, with > my audio from the TRACKER? Using OTWINCFG, and playing with the modulation control will let you test... I'd listen on another radio, and if possible watch another APRS radio to see if the packets are being decoded, or as a last resort watch the computer to see if you are making it to the APRS-IS. > 5) Also need to check my radio and its baud rate. Do not recall if > it is set to 1200 or not. It should be at that setting I assume? No need to worry about a baud rate in the radio. You said you were using a TM-V71 and an OT2... you should be feeding audio tones into that radio, not digital data. > Thanks for all the comments. They all make sense during investigation > of optimal APRS. Let's keep going to see if we can get you better reliability so you'll reduce your packet rate from 15 seconds down to something reasonable. Right now it's like you're standing in the middle of a room shouting, but none of those around you can understand what you are saying. We need to help you reduce the volume, and increase intelligibility. The end result is better communication all around. James VE6SRV
