Direwolf <> Symek Tnc3s

144.800Mhz @ 1200Baud (Two tests one on 03-23 and one on 03-24 (rx only))

The first test I did was of course not entirely fair, different antennas were used and different transmitters/receivers. Now I made a setup with the same antenna and the same receiver, so with the same audio input.
First the setup, as a computer(if I haven’t lost it.some where) I use a Raspberry PI 2B+, as a sound card I use an Fe-Pi Audio Z V2. As a receiver I use a Realistic pro 2006. It is an old receiver but still works 100%. The antenna is a x50 from Diamond. Of course the Tnc3s from Symek, and Direwolf from John WB2OSZ. I use Kissutil from WB2OSZ, this allows me to connect to Direwolf and the Tnc3s as well as save the received Frames. This makes comparing easy/easier.

Now I have made two start files, one for Direwolf and one for the Tnc3s. I start these in different terminals. I do this manually, so there is a slight delay in starting up.

/home/aprs/direwolf.sh

#!/bin/bash
# Start kissutil on Direwolf kiss port 8001
# Let it run for 30 minutes and kill the process
# Start options "timeout -s 9 1800 ./direwolf.sh"
#
# Kissutil for Direwolf save to /home/aprs/rec-direwolf
/usr/local/bin/kissutil-direwolf -o /home/aprs/rec-direwolf
#

/home/aprs/tnc3s.sh

#!/bin/bash
# Start kissutil on the /dev/ttyUSB0 for the Symek Tnc3s
# Let it run for 30 minutes and kill the process
# Start options "timeout -s 9 1800 ./tnc3s.sh"
#
# Kissutil for the Tnc3s save to /home/aprs/rc-tnc3s
/usr/local/bin/kissutil-tnc3s -p /dev/ttyUSB0 -s 38400 -o /home/aprs/rec-tnc3s
#

I start the scripts with the option “timeout” now I can specify the time how long the script runs.
Example. “timeout -s 9 1800 ./tnc3s.sh”
In this comparison, both scripts run for 30 minutes. 1800 Second. Now it is time for the comparison.

With the command “ls -A | wc -l” the number of files in the directory are counted. (Frames received.)

03-23-2020

03-24-2020

Here you can see the difference between the received frames of the Tnc3s and Direwolf. There is a difference of 73 and 125 missed frames from the Tnc3s. I tried something with the reception levels of the Tnc3s. It is To soft – Ok – To hard, there is little difference between To soft and Ok and To hard.

I did some tests with the amount of calls received. Just for fun.

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