[Packet] Packet & TH-D7A {G}

[Dr. Gerald N. Johnson]

On Sun, 2008-02-17 at 12:53 -0500, Jennifer wrote:
> Is the TH-D7A and others capable of sending the spots into Logic8 
> software, and is this Kenwood a good walkie talkie?  There are people 
> in the city that I live in that says Packet is DEAD, "sorry for being 
> voices".  I want to use my old IC-W32A into a old computer for the 
> Packet setup using software, and a TH-D7A connected to a new computer 
> feeding spots into my Logic8.  Would this setup work?  We gets some 
> bad storms during the Summer!

Communicating by packet is not in a healthy condition. Users are few,
speeds are slow. But the APRS and DX cluster frequencies have
considerable activity.

The TNC in the TH-D7A (and 700 mobile) has a reputation of lowering
throughput on a packet network. The problem is that it has only enough
buffer for one data frame, while AX-25 allows for sending as many as 7
frames at a time. So the TH-D7A accepts one frame and rejects any more
which definitely slows throughput. I've found other 1200 baud TNCs tend
to not copy more than the first frame often enough (or the second frame
is hit by a collision) that I advocate (as a keeper of nodes) that
MAXFRAME be set to 1. Which accommodates the Kenwood internal TNCs and
my decades of experiments shows connections through netromish nodes work
faster because of the reduction in sending lost frames. AX-25 does not
have the capability of accept frames out of sequence or of asking for
fills out of sequence, so all transmitted frames after the damaged frame
are wasted. When that's 6 frames out of 7 sent, its a serious network
clogger.

If the node, bbs, and cluster can be set for MAXFRAME of 1, such
collisions are far less of a problem and the Kenwood TNCs work as well
as any. With large MAXFRAME numbers, these collisions and lack of
buffers can bog down a 1200 baud network.
> 
> For the thrill of the hunt. . . . and the quick of the kill,
> Pack Animal
> DX who love you baby!
> 
> 73's
> DE
> "We ate 4 coral vicious viper"
> WA4CVV, Jennifer

73, Jerry, K0CQ