NinoTNC to Yaesu VX-6R wiring

Some folks have asked me to document the wiring/pinout for my  NinoTNC/Yaesu VX-6R cable. See the below drawing. It is based on a pre-terminated cable I got from Amazon .

Upgrade your old TNC to a USB interface

With the current resurgence of Packet Radio I decided to dust off my old Packet Radio Terminal Node Controller (TNC). There were untold thousands of these made in the late 80's and early 90's and to this day can be found at junk sales and hamfests for very modest prices.

One of the issues facing us today is that these modems typicaly used an RS232 serial port to communicate with the host computer. Take a look at your computer. Do you have an RS232 port? Most likely not. They have gone the way of the printer port and the dinosaur. Everything has moved over to USB.

The upgrade is very easy requiring only a USB-TTL interface commonly used to program the Arduino and other like microprocessors. The interface connects to the TTL facilities on the rear of the TNC.

The wiring is trivial. Using some female DuPont connector wires connect the 2 devices together as follows...

USB                             TNC

GND -------------------- GND

TX   -------------------- TX

RX  --------------------  RX

Set up your terminal program to reflect the port and speed settings reqired by your TNC then turn it on.

500kbps packet radio

Packet radio is pretty much all but dead here in the US but it seems not to be that way in France.

I recently saw a message on the AMPR mailing list about a 500kbps modem that someone in France had designed. The design files and software were put up on the Hackaday website. The design uses a handful of development boards cobbled together and has an Ethernet interface for the client computers to connect to. 

So I decided to have a go at this project. I ordered some PCB's from JLCPCB and searched the usual online suppliers for all the other parts. It took about 6 weeks to get everything together but for about $65 per modem I was able to build 2 and test them across my workbench.

One of the modems under test

I've been playing with them for a few weeks and am very impressed with them. I can sustain my MMDVM hotspot across them as well as attach a WiFi access point and make a WiFi Calling cellphone call through it too.

The downside for us here in the US is the bandwidth and speed. The FCC says that we can only use a symbol rate of 56kbaud and a maximum bandwidth of 100KHz for data modes on the UHF 70 centimeter ham band (where these modems operate). Currently the modem software will only allow links of 200kbps in 270KHz and so do not conform to the rules. 

Interestingly, this is not the only data mode to be found on the 70CMs band. Digital ATV has been around using the DVB-S standard for quite some time here. The ATV crowd erroneously reclassify their data (up to 2mbps!) as pictures/video rather than the data that it actually is. In this way they fool the FCC into allowing the mode without a rule change. So maybe that's how we do it for Packet Radio? Reclassify our data transfers as "image". After all, web pages have pictures in them. :)

Thanks to F4HDK for his design.

The network that supports the modems under test

Isolated sound card interface

I've been working towards getting my girlfriends HF rig remotely controlled. We have it installed in the sun room at the back of the house but her office is up in the attic on the 3rd floor.  This presents a problem as not only do we need to control the radio but we also need to hear what it receives and also send it some audio to transmit.

The radio control is easily achieved by using Ham Radio Deluxe and is very well documented elsewhere. For the audio portion I am using RemAud by DF3CB which is also very well documented on his website. What's not so well documented is the hardware that one might need be able to both receive and transmit audio from another location. It should be noted that whilst I am doing this from another room 3 floors away it could equally be done from 3000 miles away over the Internet.

If you are familiar with Skype then you'll know that it uses the sound system installed into your PC. The microphone is usually sourced from your webcam and the speakers let you hear the other person. RemAud is a similar application. It uses the same audio sources. And that's where the difficulty begins. Your HF rig cannot use the mic on your webcam.

Luckily this problem has been solved many times before. A simple radio-computer sound interface is all that's needed on the radio end. It needs to move audio from the PC to the radio and back. It also needs to key the PTT to enable the radio's transmitter. This is what I came up with.

It's an isolated audio interface with USB based PTT keying. I made it from the junk box. The Audio part is a copy of the many transformer based sound card interfaces one can find on the 'net. The transformers isolate the electrical path between the radio and the computer in an effort to reduce computer noise getting into the radio.

The USB part is a USB to serial interface that I had meant to use in an Arduino project but never got around to it. I added a small bit of circuitry to invert the signal from controller chip and also isolate the PTT from the computer.

I also added a USB sound card adapter to the PC to manage the sound instead of using its built in sound facilities. I'll be moving it all to the rear sockets of the PC and there are no sound outputs there.

It works very well. However, I am not happy with it. The PTT should really be isolated via a opto-isolator and it's larger than I'd like. So I set about designing another interface. This time it's more compact and has "proper" sockets etc. It's also fully isolated and can also key some CW too.

I designed a board for it too. You can get it at Oshpark

And here's the finished result. It works perfectly. It's also much smaller and now fully isolated. I used a PS/2 male-male extension cable that I got from Microcenter to connect the data port on the rig to the interface. At $8 it was not worth my time or effort to try soldering a cable myself.

There was a caveat that took me a few days to work out. Direct from the factory the FT232 USB-serial chip has its signals inverted. This is correct as it actually converts from TTL to USB, expecting another chip to do level shifting up to the +/-12v that is RS232. But the chip makers have thought of that. They have a tool on their drivers website that allows you to change the signalling on any of the pins. I inverted DTR and RTS so that they would go high when applied thus powering the LED in the opto-isolator. 

The Bill Of Materials is quite trivial;

• FTDI FT232RL USB to Serial chip x1
• 10K x1
• 1K x3
• 3MM LED x1
• 0.1uf x2
• 10uF x1
• Mini-USB 'B' x1
• 4N25 x2
• 3.5mm audio socket x3
• 42TM016 600:600 audio transformer x2
• PS/2 6 pin mini DIN socket x1

Programming the Motorola SM50 under Linux

The Motorola SM50 and SM120 are quite a common radio and pop up on eBay all the time for modest prices. As with all Moto gear they come in a variety of models; wideband, narrowband, 2 channel, 16 channel, 40 watt, 4 watt etc etc etc. There are various model decoders available around Al Gore's Interweb Tubes so we won't be covering that here.

I am the proud owner of quite a pile of SM120 M44DGC20C2AA (40W UHF high wideband) models which are ideal for a repeater blabber box, GMRS or FirstResponder use such as your local Ambulance Squad.

Programming them back in the early 90's (yep, they are even older than that!) was by way of a DOS program running on a lowly i286 PC. But hold on, we are on Linux. How's that gonna work? Take a quick look at this youtube video ...

Things you'll need:

A Linux box (DUH!)
DosBox emulator software (apt-get install dosbox)
SM50 programming software (can't help you there but it's not hard to find)
Motorola GM300 style programming cable or "RIB" (I use a USB one from ebay)

How to do it:

Using your favourite terminal program (I use Yakuake) fire up the dosbox emulator by typing 'dosbox'. If you have a Z: prompt then that part works.

Unpack your SM50 software into a folder. Navigate to that folder and then fire up your favourite text editor. we'll be making a config file called 'sm50dosbox.conf'. Mine looks like this ...

[cpu]
core=auto
cputype=auto
cycles=191
cycleup=10
cycledown=20
[serial]
serial1=directserial realport:ttyUSB0
serial2=dummy
serial3=disabled
serial4=disabled
[dos]
xms=true
ems=true
umb=true
keyboardlayout=auto
[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.
mount C /home/g7ltt/raid/Filestore/DOS
mount M /home/g7ltt/raid/Filestore/motocd/SM50/R030000
m:
m:\SM50.EXE

Adjust the 'serial' lines to match your USB port. Also adjust the 'mount' lines to reflect your path. In my case 'C' becomes C: and holds a few DOS utilities. The 'M' becomes M: which contains my SM50 software. 

Save your file and the type 'dosbox -conf sm50dosbox.conf' and watch it all fire up. You'll have to configure the dos software to use COM1 but otherwise you'll be programming in no time.

In theory this should work for other Motorola DOS based programming tools for other radio's. However, I've not been able to get the GM300 or Maxtrac software to communicate with the radio. It seems that (for USB cables at least) the serial speed of 930bps is not supported by either the OS or the emulator.

If you get one of the other DOS programs to work please do drop me a line.

JNOS on Raspberry Pi

Inspired by the PiGate and already possessing the constituent parts (including the 3D printer to make the enclosure) I decided to try my hand at getting a JNOS system together. TCP/IP over radio fans will probably remember JNOS from way back when. Good news! It's still being maintained by Maiko Langelaar, VE4KLM http://www.langelaar.net/projects/jnos2/

As it turns out this project was quite trivial to put together. Maiko has done all the hard work with his software and John Hanson, W2FS did more hard work with his TNC-Pi hardware

 

The top 2 pictures show a RPi3 and a TNC-Pi housed in the PiGate 3D printed enclosure (should have printed it in OEM Orange!). The bottom picture shows the completed PiGate hardware connected to a KPC3+ via a direct audio cross-over cable.

So how do I build the JNOS? I started with a shiny new 8GB SD card that I picked up at Microcenter for $4 and a RPi3 which I also got from Microcenter for $30. I also downloaded the latest edition of Raspbian Jessie Lite. The Lite version does not have a GUI. Real men can use the Linux command line. /JFDI!! I'm not going to tell you how to install the RPi and get it onto your network. There are plenty of other resources available for that.

Before we start, have you confirmed that your TNC-Pi works correctly? You can use the tools from the TNC-Pi website to talk to the modem? You removed and added lines per the instruction on the website? Good.

Let us start by installing the the latest updates, patches and a few required libraries ...

sudo apt-get update
sudo apt-get upgrade

sudo apt-get install libssl-dev libncurses5-dev libncursesw5-dev

Now get the latest sources from Maiko's website and unpack it. Navigate to the 'src' directory. Copy the config.h.default file to config.h and edit it to your requirements.

Now for the hard part. Go ahead and 'make' JNOS. It'll take about 10 minutes so go and make a nice Brownian Motion producer.

So it's JNOS, right? So that means you'll need to craft all the relevant config and support files, autoexec.nos, ftpusers, rewrite, forward.bbs etc. But just to be nice I'll give you a head start on the modem config in autoexec.nos ...

#
# ---------- TNC-Pi specific----------
#
# We are using a single TNC-Pi KISS modem from Coastal Chipworks (hi John!!) configured to use the serial port @ 19200bps
attach asy ttyAMA0 - ax25 pitnc 1024 256 19200
# That's all. Carry on with the config
#

And that's really all there is to it. As stated previously I connected the RPi/TNC-Pi directly to my KPC3+ via a cross-over cable. I was able to connect to the JNOS BBS prompt as seen below. It just works.

Some links ...

https://sites.google.com/site/bpq32wiki/home/installing-linbpq/simple-kiss-terminal
http://www.langelaar.net/jnos2/downloads/linux/
http://65.41.143.157:800/docs/tncpi.html
http://k4gbb.no-ip.org/docs/Raspberry.html

Express Tracker as a KISS TNC

"AX.25 style Packet Radio is dead".That's what the old timers will tell you. They'll tell you it gave way to the Internet because the speeds were better and you didn't have to modify your rig. They may be right in that statement but when you're in a Red Cross shelter with no network access Packet Radio may be your only way to move that pile of ICS213 forms that have just arrived at your station.

In my search for a modern Terminal Node Controller (fancy term for data modem) I've looked at all sorts of designs. Readers of my blog will be familiar with my various attempts to find something that will connect to the USB port of a modern PC/Laptop for OEM type uses.

I _think_ I've found it. Say "hello" to the Express Tracker from RPC-Electronics. It's a small translucent box that's not quite as big as a packet of cigarettes. It can do APRS tracking when fitted with a GPS RX, act as a APRS Digipeater and most importantly for my needs has a _full_ KISS implementation.

KISS? What's that? I'm not gonna go into that here but suffice to say that it's a way of using a radio modem without all the overhead of a Terminal Node Controller getting in the way. Go here for more about KISS. KISS is interesting to me (and hopefully you too) because it presents a standard interface that many software packages can talk to.

So in my scenario I foresee our local ham club deployed at Red Cross shelters across the town after a severe storm. The local OEM has requested that all traffic be submitted digitally via ICS213 and similar forms. The problem is that there is little to no power to run email and fax machines etc. Enter Packet Radio. It'll run from your laptop and use the same power supply you are running your station from.

I'm not going into how you would operate your chosen package or why this one is better than that one. What I will do is show you how to add your Express Tracker to your Windows and Linux PC's. Mac users _may_ be able to follow the Linux instructions.

OK, Windows first. We are going to use AGWPE to attach to the ET. It's all trivial really. Plug in the USB cable and install the drivers if necessary. Then fire up AGWPE and configure your TNC as below. Your port number may be different to mine. Click OK and then restart AGWPE.

So now you have AGWPE running your ET. Fire up your favourite packet application such as Outpost Packet Manager (pictured below) and configure it to use AGWPE. That's it. You're now on Packet Radio using your Express Tracker.

Here's a few shots of a mail swapping session I had between OPM (Windows) and my real TNC;

And this is OPM talking to JNOS on Linux;

Linux is much simpler (isn't it always?). The modem comes out of the box pre-configured for KISS @ 19200bps. Simply plug it in, find out what the serial port is called (/dev/ttyACM0 on my machine) and then either kissattach /dev/ttyACM0 $PORTNAME $IPADDRESS to run the ET under the native AX.25 tools or add the following to your autoexec.nos file ...

# ---------- Express Tracker specific ----------

#

# We are using a USB<>Serial interface which forces hardware handshake. KISS spec says no handshake of any type so we have to turn it off

shell stty --file /dev/ttyACM0 -crtscts # nip out to the OS and turn off the RTS/CTS on the USB adapter

pause 1 # wait a second for the command to complete

attach asy ttyACM0 - ax25 etrack 1024 256 19200 # attach the Express Tracker to JNOS as a KISS device @ 19k2bps

# That's all. Carry on with the config

#

And that's how it's done!

$100 APRS Tracker Mk2

Way back (2001) before they invented Internet 2.0 I built an APRS tracker for less than $100. It was a collection of stuff slapped together into a box and sported a TinyTrak tracker, GPS receiver and a 2 watt transmitter. In its day it was quite an achievement. Most APRS implementations would run over $150 and require an old TNC and a full FM transceiver. GPS's in those days were also big and ugly too. To this day I still get requests for the radio I used.

Well, over the years it has had updates and repairs and even had a 10W linear amplifier added to improve its range but yet it was still a pile of components slapped together into a somewhat large box. It finally gave up the ghost and forced me to go a different route. I briefly looked at creating my own tracker but abandoned it due to time constraints and other projects.

That was then. This is now. I bought a new car recently and am in the throws of moving my radio gear into it. Whilst I have a "black box" radio that will do APRS very well I still want to run my own bespoke APRS tracker. So that led me back to the $100 APRS Tracker.

Looking around the shack I found an old Motorola SM50 left over from a D-STAR HotSpot project. All I needed now was the tracker and a GPS receiver. Then I remembered that I had looked at this project a few years back. At that time I was playing with Ublox NEO-6 GPS modules for use in NTP time servers. These are sub $10 GPS receivers for adding to your projects. They are trivial to use requiring just 3.3v and an antenna. As you can see from the below picture I was able to integrate one into a tracker prototype (it's that white square blob).

But it didn't work. Or rather, it worked badly. Whilst it would talk to the config software when attached to the PC and indeed would send a beacon it wouldn't send any position data. Now I remember why I abandoned it. Having a little more time now I took another look. 

Turns out that the problem was trivial. In its old form (pictured above) the GPS was spitting out position data at 9600bd but the PIC microcontroller was expecting the data at 4800bd. DUH!! The fix was to ground one of the config pins on the GPS thus forcing it into 4800bd mode. In writing this page and getting the files etc together I've come across some auto detecting firmware that makes this problem go away. And I can tell you that it works wonderfully! If only I had bothered to look a little harder the first time around.

So let's do some accounting ...

• Motorola SM50 FM transceiver    $30  ebay
• Tracker PCB                                  $8    oshpark.com
• Ublox NEO-6 GPS RX module     $12  ebay
• PIC 16F628 microcontroller          $3    ebay
• SMA antenna connector                 $1    hamfest
• Motorola pre-wired 16 pin plug     $4    ebay
• GPS "hockey puck" antenna          $5     ebay
• 1/4 wave 2 meter antenna               $8    ebay
• Mag mount for 2M antenna            $14  ebay

That's a grand total of $85. And if you already have some spare 2M antennas kicking around you can shave another $22 of that for a potential $63.

So I've parked all the board stuff on oshpark.com for you to order. You'll get 3 boards for $22. The PCB will allow you to use any current Ublox NEO-x GPS modules. They'll spit out 9600bd data so you'll have to use 9600bd compatible PIC APRS code. Luckily I've linked to that below. You can also change the PIC for a slightly better one which will have more facilities. 

Eagle files for download ...

APRSTracker_GPS_9600bd.sch

APRSTracker_GPS_9600bd.brd

PIC microcontroller code for download ...

kf163tracker-2.0.2.iso It's a bootable Linux disk. Contains firmware, manuals and config software.

Thanks to DK7IN for his original idea and PE1ICQ for his expansion of this idea and his excellent code.