Loading ...
Sorry, an error occurred while loading the content.

15924Re: [tracker2] RE: T-2 audio level ?

Expand Messages
  • James Ewen
    Sep 19, 2013

      So, this capture is done at KC5HMI-5, correct? It looks to be covering about 22 minutes from 11:35 to 11:57.

      I deleted all the waypoint information from the file. Does the digipeater have a GPS attached? If not, kill the waypoints, and you'll get less noise to look through.

      We can see that this site has digipeated at least 5 packets, because we can see it's callsign in a packet that has been handled by another digipeater afterwards.

              Line 3: K5ARC-2>APN390,KC5HMI-5*,W5KRO-2*,WIDE2*:=3006.16NN09054.51W#PHG9490W2, SSn-N, K5ARC Digi Line 8: N5UKZ>APU25N,KC5HMI-5*,W5KRO-2*,WIDE2*:@182337z3023.36N/09101.15W_197/007g016t085r000p000P001h72b10143/{UIV32N} Line 20: W5KRO>APWW10,KC5HMI-5*,WIDE1*,W5KRO-2*,WIDE2*,:/184300h3031.87N/09102.05W_304/001g006t082r000p001P001h70b10144 Line 24: W5KRO>APWW10,KC5HMI-5*,WIDE1*,W5KRO-2*,WIDE2*,:;146.835-R*182345z3046.44N/09121.01WrMissLou RPT 146.835- Tone 114 Line 29: N5UKZ>APU25N,KC5HMI-5*,W5KRO-2*,WIDE2*:@182347z3023.36N/09101.15W_114/006g015t084r000p000P001h73b10143/{UIV32N}

      This doesn't mean these are the only packets that were digipeated, but because they were handled by another station after this digipeater digipeated them, we see the evidence in the packet.

      We can also tell what alias is being supported. K5ARC-2 and N5UKZ are using a WIDE2-2 path, and we know this digipeater handled those packets.


      W5KRO is using WIDE1-1, and the digipeater also handled those packets.

      So from that, we know that KC5HMI-5 is supporting WIDEn-N up to at least 2 hops.

      Let's look to see if we can see those 5 packets we know were handled by KC5HMI-5 in the APRS-IS stream. Looking through the last 1000 packets for K5ARC-2, we don't see a single instance of KC5HMI-5 handling a packet.

      Looking at the info page for KC5HMI-5, it tells us that it has heard K5ARC-2 5 times this month, with the last time being September 11th. The raw packets you provided however show the date to be the 18th... 
      N5UKZ also shows as not being heard ever.
      W5KRO is reported as only being heard 2 times all month, but we have proof of 2 packets above on the 18th which don't show below.

      callsign ▾pkts first heard - MDTlast heardlongest (rx => tx)longest at - MDT
      K5ARC-2 52013-09-11 08:49:582013-09-11 20:30:00 EM40NC > EM40LO56.7 km 165°2013-09-11 20:30:00

      W5KRO 22013-09-17 07:50:282013-09-17 23:03:31 EM40LM > EM40LO7.7 km 161°2013-09-17 23:03:31

      So, once again I will reiterate that "One cannot use the APRS-IS feed for accurate analysis of RF propagation and network analysis."

      Karo, do you have a capture log of the same time period from your W5KRO station? You state that your station hears more than the digipeater.

      If that is true, then capture logs from both stations during the same time period will show the proof of that statement.

      What else can we learn from the packet log?

      We see that W5KRO-2 is a mobile station using a Tracker 2 with an outgoing path of WIDE1-1,WIDE2-1. We can also see that W5KRO-2 is acting as a digipeater since it is digipeating packets as seen below:


      Mobiles driving around acting as a digipeater are usually frowned upon due to the detrimental effect this has on the reliability of a well planned and deployed APRS network. Shutting down this mobile digipeater would help the network reliability in the area.

      We also see that W5KRO is also acting as a full digipeater from this evidence:

      N5YHZ>APU25N,KD5QZD-12*,W5KRO*,WIDE2*:>261135zUI-View32 V2.03

      K5ARC-2 is a KPC-3+ running v9.0 firmware, running at a reported 81 watts of power at 150 feet with a 9 dB gain antenna and it is choking out the network using a WIDE2-2 path every 10 minutes. A digipeater effectively gets an extra hop based on the fact that it is a digi. This 2 hop path from a digipeater is equivalent to a regular user running WIDE3-3. Proportional pathing would reduce the load this station is placing on the network in the area.
      This digipeater is also sending a number of repeater objects.
      The 147.225 object goes out locally, which is good, but the 145.310 and 146.985 objects go out via 2 hops. Can you access these repeaters from a hundred miles away or so?

      K5LSU-5 is gating echolink objects into the local area via 2 hops at a fairly rapid rate.

      KD5QZD-2 reports itself as a digipeater, yet is asking for help from home fill-in digipeaters because it can't be heard by other digipeaters. Either they need to stop using WIDE1-1 as a path element, or shut down a digipeater that is basically useless if it can't be heard by other digipeaters. The second path element used by this digipeater is not supported. WIDE-2 is not a valid hop request.

      W5LAK as well is a digipeater asking for help from home fill-in digipeaters in order to be heard.

      In Baton Rouge, we find the KD5QZD-2 digipeater, and less than 8 miles away, W5KRO acting as a digipeater, and then just slightly further away, at 11 miles, KC5HMI-5 is a full digipeater. At about 23 miles, KD5QZD-12 is another full digipeater, at 27 miles, K5ARC-2 another full digipeater. Finally W5LAK at about 40 miles acting as a digipeater. We can't forget that W5KRO-2 is driving around acting as a mobile digipeater as well.

      On fairly flat ground, you should be able to get a good 20 miles out of a digipeater with some modest antenna height. That would mean placing digipeaters about 40 miles apart, yet we find a plethora of digipeaters all within close proximity. These digipeaters all are programmed to act on packets heard. With so much overlap, you can end up with heterodyning, and collisions, which causes decreased network reliability rather than increasing it.

      Of course, there can always be local terrain and other issues that may require specific digipeater placement decisions, but I would suspect that there are far too many digipeaters located far too close together to be able to achieve reliable APRS network communication.

    • Show all 9 messages in this topic