PROJECT    TNC

Where we build things and learn stuff.

March 13, 2024 -- RMS GATEWAY IS DEPLOYED AND READY FOR USE!    

WA6BGS-10  on 145.070MHz

https://winlink.org/  click on Tools, zoom into San Diego county and you'll see our dot.  Choose "Packet" at the top of the map.

TNC CABLES

If you are finishing your TNC solder project and are ready to attach your kit to a radio, use these guides to help you with the cable fabrication.

I suggest you find a 3-4 foot piece of STRANDED Cat5 cable because stranded will tolerate flexing much longer than solid cat5.  The TNC uses four wires from the DE9 connector for communication to your radio.   Pin 6 and 9 are bonded on the PCB as ground, only on version 4 of the boards.  We assembled version 4.  Tying them together in your cable will not hurt and it will make your TNC cable compatible with version 3 of the Nino boards.    For good measure you can tie all the other stripe cables together and ground them.  We are transmitting audio signals, so having a bunch of grounded wires inside shouldn't hurt.

Looking at the solder cups of the DE9 connector,  use the solid color wires according to the color codes in the drawings.  At the radio end, solder the appropriate rings tips and sleeves to your cable - use a multimeter to test the pigtail connectors ensuring you have selected the correct pin.  The supplied DE9 shell comes with several strain relief bushings and one of them fits perfectly around the jacket of a CAT5 cable.    Once the 9 pin shell is assembled, you can begin work on the radio end.

Note the drawings here.  This is what I have assembled and tested personally.    There are some builders who requested a DIN-6 and DIN-10 connector for their radio. Verify your radio DIN6 pinout instructions for connecting this cable.   The TARPN documentation page gives some detailed directions for setting the delay and TX audio levels.  The default settings we used during our assembly event will probably work well for most radios, but for a mobile unit using a dedicated packet port (not speaker and mic) you may need to adjust your TX or even modify the dip switch #1 on the SIGNALS group of switches.  My radio (FTM400) can take a 300mVp-p signal input, and the default settings for a mic only generate about 120mVp-p.  I sound weak.  You'll need a scope to properly measure this and the description is listed here.    https://tarpn.net/t/nino-tnc/n9600a/n9600a_operation.html   Go do section 14-2  SIGNALS switch, and read up on Data vs Mic, and make necessary adjustments using RV1 (the 10k trim pot in step #18  https://tarpn.net/t/nino-tnc/n9600a/n9600a4/n9600a4-assembly.html  )

Click to see three different hookup diagrams here.  For Baofeng and Yaesu radios, setting the radio volume around 33% to 50% seems to give good results with this TNC.  Setting the volume too high will overdrive the TNC and you may get poor reception.  An easy method for setting the volume on your HT (any of the models) is to slowly turn the volume up until the TNC CRC light begins to flicker, then back down until it stays off.  A volume setting too low means the TNC will have a hard time decoding the audio.  Set too high and the TNC thinks everything is a bad packet as you are overdriving the audio input.

The four ring Yaesu cable can be fabricated with the resistor and capacitor in-line, and shrink-wrapped to protect the junction.  The capacitor and resistor will fit inside some shrink wrap.  Add some hot-melt glue to help bind the small wires together, then shrink the tubing on top.

BAOFENG SETTINGS FOR PACKET

The Baofeng radios have several menu items you will want to change when using these HT radios for packet.  When you modify these settings for packet use, the radio will need some of them set back if you must field program your radio for a new repeater.  If you have never field programmed your Baofeng radio for a repeater... you should try it.

Some of these settings will be obvious, but others were suggested on various forums and I have collected them here for your convenience.
0 SQL = 0 off
2 TXP = high
3 SAVE = off
4 VOX = off
5 WN = wide
7 TDR = off
10 R-DCS = off
11 R-CTCS = off
12 T-DCS = off
13 T-CTCS = off
14 VOICE = off
25 SFT-D = off
26 OFFSET = 00.000
35 STE = off
36 RP-STE = off
37 RPT-RL = off
39 ROGER = off

PRINT A CASE

The TARPN project has released STL files for 3d prints, based on the most current bill of materials.  This case will work for the TNC kits we are building.

TNC 3d print file TOP    TNC 3d print file BOTTOM 

Link to the assembly instructions for the TNC v4  https://tarpn.net/t/nino-tnc/n9600a/n9600a4/n9600a4-assembly.html 

Here is another 3d print model for the TNC.  This has larger openings for the LED and USB/Serial and dip switches.  
https://www.printables.com/model/522821-more-forgiving-ninotnc-case-by-matt-m0mfz 

SOLDERING WORKSHOP

UPDATE January 11, 2024 - Soldering workshop went really well.  Under the rosin haze of solder smoke and a whole bunch of soldering irons,  only Chuck.W burned himself, and David.K demonstrated his superior vision by assembling a board without needing glasses or a magnifier.  Some day David, you'll be right there with the rest of us, needing readers and bright lights so enjoy!  Three TNC builders successfully completed their boards during our session, tested and validated from a laptop.  The next phase of your build involves creating a TNC cable to interface with the radio.    Working with Rob.H, I was able to send a winlink P2P message across the room using our small HT's and the Nino TNC boards.  Huge success!  I can check that box now.

Thanks everyone for coming and putting your essential skills back to use, building something fun, and laying the groundwork for further packet communications.  For those who want 3d printed cases, these things take a few hours to produce and we will be in touch about getting them fabricated.  Bring your finished kits and laptops and radios back in February and we'll all sit in the same room and try packet communications with each other.  If you are not already connected and using the Winlink network, get started and bring your questions next month. 

If you need help fabricating the cable to your radio... we can help.  For Baofeng/Alinco/Anytone/Wouxon  the pinout is easy.  For Yaesu HT, it is one cable.  For your larger mobile units, you should have received a Mini DIN-6 or DIN-10 cable to go with your DE9 connector.  Stay tuned.

Ray.W and I are going to start the process for building a club RMS gateway, so more hams can use their new TNC's, and to help populate some much needed coverage back into the San Diego area.  

If you want the latest 3.34 firmware on your TNC (you have 3.33 right now), bring it in February.  This takes about 3 minutes to upload.

December 2023 - Project Proposal

Build an inexpensive kit TNC for the purpose of connecting your HT and laptop to the Winlink mail system, and explore additional Amateur Radio packet modes.  A project approved by the club members in attendance on November 9, 2023.

The purpose of this project:

• Encourage anyone with a laptop and a HT and a technician license to learn a new communication tool.  This service is available in most urban areas using 2m, and around the world on HF.

• Teach inexperienced builders how to solder using thru-hole components.  

• Show uninitiated hams how the Winlink system works and where it works.  It is free to use, but the software can be optionally registered for $24 as a donation toward development.  Winlink software for your smartphone can cost between $8 and $15.  

• There are other options for those who are willing to compile code or use programs that are not fully featured as Winlink Express.  You can research these options at  https://winlink.org/ClientSoftware and we would love to hear a report on how well they work.

The Project Parts:

• First, we need you and whatever soldering skills you have.  

• This is the project we will be building  https://tarpn.net/t/nino-tnc/nino-tnc.html  The estimated cost for the board plus parts and a cable is between $40 and $55, which includes the PCB and CPU from Etsy, and the thru-hole components from Digikey or Mouser.  The club will collect names and a down payment, then order parts and distribute these kits. 

• A single kit, if ordered individually, may cost you a bit over $50 unless you substitute parts already owned.  We hope to get enough committed builders to make a bulk purchase and get the price down around $42.

• 3D printed case, using STL files obtained from thingiverse or the Tarpn site, and you can create your own.  3D printers are available at the SD libraries, or find a friend to help.  If you have never used a 3D printer, find someone to help you get started.  These things can be awesome or frustrating, or both.

• A USB-A to USB-B cable.  Everybody should have these laying around, but if not... find someone who will give you one.  These are the old style big connector USB types.

• Kenwood style plug with DE9 connector.  This is the audio interface from the TNC to your radio, most commonly found on inexpensive radios like Baofeng, Alinco, Anytone, and others.  Yaesu uses a 4 ring single connector, and your larger mobile radios use the multi pin DIN connectors.  We will be ordering the Kenwood style cable for this kit, and if we have enough interest in other brands, will make an effort to buy those in bulk also.  You can buy pre-made cables for nearly any radio style from https://hammadeparts.com 

The Project Plan:

• Starting now until December 15, 2023, we will collect names and money from all interested parties.  Contact us directly by president@wa6bgs.us and let us know the following things.  How many kits you want.  What radio you intend to use.  Your level of soldering skills - this is thru-hole soldering, no surface mount - and do you need help with this project?  You can bring your payment to our club Ham Potluck on December 14, a partial payment will be sufficient until we know the total price based on the number we order.  Please work with me here so we get some money and commitment up front and don't get stuck with a dozen TNC kits.

• The club will place an order for boards and components, hopefully to arrive before January 11, 2024.  

• While you wait, prospective builders or interested participants will be encouraged to get registered and familiar with Winlink software.  Begin your training on a PC with a reliable internet connection.    It's free and you need a HAM call sign to get started.  Go here and read up https://winlink.org/ .  There are plenty of how-to videos and documents to help get started.  Once you are familiar with how Winlink works on an internet connection, you'll be ready for jumping onto RF!

• January 2024 meeting - deliver the kits and we host a solder workshop.  The kit claims to have a ONE HOUR assembly time.  The PIC processor ships preloaded with code, so when you are done, cable up to your HT and send/receive mail.  I'm sure it will be a bit harder than this.

• February 2024 meeting - follow up and debugging.  Bring your HT, laptop, TNC, and we can all learn to send mail by simplex.  

The Other Things:

• What are the alternatives to this TNC?  MFJ makes a TNC, and there is a TNC board you can attach to the top of a Raspberry Pi, and use the small computer for your own projects.  These are sold online and from HRO, and have a lot of useful features.

• How about Direwolf?  Yes, you can use software and a USB sound card (or your computer soundcard) to accomplish things this TNC does.  https://github.com/wb2osz/direwolf  There is nothing stopping you from doing both the Tarpn TNC and exploring other software options.  It's good to have options!  Don't limit yourself.

• Chromebook?  Raspberry Pi? Netbook from the early 2000's?  The amount of processor power needed to decode 300 baud and 1200 baud packet radio is well within the capabilities of a modern computer.  The limitations of the Chrome OS may force you to use android style phone apps to accomplish this task.  Older laptops and netbooks (remember those?) should work fine as they run windows or linux easily.  Packet radio has roots in the days of the BBS and DOS.

• If you have experience with this TNC or others, and have done packet radio recently, come and share your experiences, give some friendly advice, and encourage others to use packet in cool new ways.