Mobilinkd TNC3 User manual

TNC3 User Guide
Mobilinkd TNC3 User Guide
Rev B - 2019-06-10
Thank you for purchasin your new Mobilinkd TNC3 Battery-powered Bluetooth TNC.
This TNC is desi ned to suit all aspects of the Amateur Radio community. It is ready to plu in and o
with easy to use and intuitive confi uration software, and it is completely open for experimentation.
The schematics are published and all software used in the TNC is open source and available online.
Warning
Do not store your TNC where prolonged exposure to extreme temperatures can occur (such
as in the trunk or cabin of a car). It can cause permanent damage.
•hort term storage: -4° – 140°F (-20°C – 60°C)
•Long Term torage: 32° – 77°F (0°C – 25°C)
•Operating Temperature: -4°F – 131°F (-20°C – 55°C)
Regulatory Information
This is the stuff I am le ally obli ated to put in this document If I am obli ated to put it in here, you
are obli ated to read it. Enjoy!
United States of America
Contains FCC ID:A8TBM78ABCDEFGH
This device complies with Part 15 of the FCC Rules. Operation is subject to the followin two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept any
interference received, includin interference that may cause undesired operation
This equipment has been tested and found to comply with the limits for a Class B di ital device,
pursuant to part 15 of the FCC Rules. These limits are desi ned to provide reasonable protection
a ainst harmful interference in a residential installation. This equipment enerates, uses and can radiate
radio frequency ener y, and if not installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no uarantee that interference will not
occur in a particular installation. If this equipment does cause harmful interference to radio or
television reception, which can be determined by turnin the equipment off and on, the user is
encoura ed to try to correct the interference by one or more of the followin measures:
• Reorient or relocate the receivin antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
• Consult the dealer or an experienced radio/TV technician for help.
• Or, you know – you’re a licensed amateur radio operator. Figure it out!

TNC3 User Guide
Canada
Contains transmitter module IC: 12246A-BM78SPPS5M2
This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the
followin two conditions: (1) this device may not cause interference, and (2) this device must accept
any interference, includin interference that may cause undesired operation of the device.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts
de licence. L'exploitation est autorisée aux deux conditions suivantes: (1) l'appareil ne doit pas produire
de brouilla e, et (2) l'utilisateur de l'appareil doit accepter tout brouilla e radioélectrique subi, même si
le brouilla e est susceptible d'en compromettre le fonctionnement.
Under Industry Canada re ulations, this radio transmitter may only operate usin an antenna of a type
and maximum (or lesser) ain approved for the transmitter by Industry Canada. To reduce potential
radio interference to other users, the antenna type and its ain should be so chosen that the equivalent
isotropically radiated power (e.i.r.p.) is not more than that necessary for successful communication.
Conformément à la ré lementation d'Industrie Canada, le présent émetteur radio peut fonctionner avec
une antenne d'un type et d'un ain maximal (ou inférieur) approuvé pour l'émetteur par Industrie
Canada. Dans le but de réduire les risques de brouilla e radioélectrique à l'intention des autres
utilisateurs, il faut choisir le type d'antenne et son ain de sorte que la puissance isotrope rayonnée
équivalente (p.i.r.e.) ne dépasse pas l'intensité nécessaire à l'établissement d'une communication
satisfaisante.
The TNC does not contain a user modifiable antenna – unless you have a soldering iron. Then all bets
are off. You’re an ham radio operator. Go wild.
Europe
The Microchip BM78 radio module inside the TNC3 has been fully tested to comply with EC
requirements for CE markin . These tests include Health, Safety, EMC and Radio. Further testin of
the final product (the TNC3) was conducted to ensure compliance of the inte rated product.
The TNC3 is RoHS compliant. Still, I would avoid eating the PCB if I were you.
Japan
Inte ration of this module into a final product does not require additional radio certification provided
installation instructions are followed and no modifications of the module are allowed.
So, if you are in Japan, you cannot modify the Bluetooth module. You’ve been warned.

TNC3 User Guide
Korea
I think Korea requires that I provide a user manual in Korean. I don’t (yet) speak, read or write the
language. Sorry. Give Google Translate a try:
Taiwan
注意 !
依據 低功率電波輻射性電機管理辦法
第十二條 經型式認證合格之低功率射頻電機， 經許 可，
公司、商號或使用者均不得擅自變更頻率、加大功率或 變更原設計
之特性及功能。
第十四條 低功率射頻電機之使用不得影響飛航安全及 干擾合法通信；
經發現有干擾現象時，應立即停用，並改善至無干擾時 方得繼續使用。
前項合法通信，指依電信規定作業之無線電信。
低功率射頻電機須忍受合法通信或工業、科學及醫療用 電波輻射性
電機設備之干擾。

TNC3 User Guide
Overview
This uide will introduce you to the key features of the TNC, its connectors, switches and indicator
LEDs. Most of this manual illustrates the confi uration and operation of the TNC usin an Android
device and Android software. However, the TNC will work with any operatin system and software
that can talk to a KISS TNC over Bluetooth SPP (Serial Port Profile), Bluetooth LE usin our custom
service, or via USB CDC (serial port emulation).
K SS TNC
The TNC3 is a KISS TNC, which means that it is purely a modem and not really a terminal node
controller. A more accurate description of the TNC3 and all KISS devices is a KISS modem. The
TNC3 does not manipulate the packets it receives in any manner. It cannot, by itself, di ipeat (relay)
packets or do any store and forward operations associated with an intelli ent TNC. This is an
important point that can be a source of some confusion. A KISS TNC simply encodes and decodes
di ital information as audio that can be transmitted over the air by a radio on a voice channel.
The Mobilinkd TNC System
The Mobilinkd TNC System is comprised of three physical components: A radio, the Mobilinkd TNC,
and a computer, tablet or smart phone that supports Bluetooth SPP or LE-TNC. The TNC connects to
the radio with a cable and talks to the smartphone or computer via Bluetooth connection.
The TNC3 is also able to talk to the phone, tablet or computer via USB serial port emulation.

TNC3 User Guide
TNC Switches, Connectors and ndicators
The Mobilinkd TNC3 has three switchs, two connectors and two indicators. Each of these is shown in
the ima e and described below.
S1 – Power button. Press briefly to turn on. Power/BT LED will flash. Press briefly to turn off. The
power/Bluetooth LED will turn off.
S2 recessed reset switch. To reset the TNC, carefully insert the tip of a pen into the hole and ently
depress the switch.
S3 recessed DFU button. This is used when updatin the device firmware. To enter firmware update
mode, carefully insert the tip of a pen into the hole and ently depress the switch.
USB – Micro-USB connector for char in /power/USB serial port.
TRRS – 3.5mm TRRS audio connector for Radio.
1. Tip = Speaker (audio input to TNC)
2. Rin 1 = PTT (Simplex PTT mode)
3. Rin 2 = Mic (and PTT in Multiplexed PTT mode)
4. Sleeve = GND/Common
RGB LED – This is a mult-function indicator. The blue LED flashes slowly when disconnected,
flashes a double-blip when connected via Bluetooth, or flashes a triple-blip when connected via USB.
The LED shows red when transmittin and reen when receivin data.
Power button
TRRS
Micro-USB
RGB LED
Red LED
Reset Button
DFU Button

TNC3 User Guide
Red LED – Char e indicator. On when connected to USB and char in , otherwise off.
Before First Use
The battery will not be fully char ed when you receive the TNC. It is always best to plu in a micro-
USB cable and char e the battery before first use. When the red LED turns off, the battery is char ed.
The battery will typically last for 48 hours of continuous use.
TNC Cable
The TNC must be connected to the radio via a cable. Mobilinkd sells cables for a wide ran e of hand-
held radios, as well as data cables for mobile and base radios with TNC ports.
The cable connects four si nals:
1. Audio in (this is the speaker or data out on the radio)
2. Audio out (this is mic or data in on the radio)
3. PTT si nal
4. Common (GND)
On some hand-held radios, the PTT si nal is multiplexed onto the audio output. In this case, the
dedicated PTT si nal is not used.
Unlike with the TNC1 or TNC2, the TNC3 incorporates ferrite beads on the PCB so attachin a ferrite
bead to the cable is not the necessity that it once was. The TNC is expected to operate properly without
a ferrite bead on the cable. However, if the cable is bein run ri ht next to the antenna, it does not hurt
to add one.
Radio Settings
Each radio is different, so havin a comprehensive list of optimal settin s in a document like this is not
possible. However, it is important to understand what radio settin s impact the performance of the
TNC and its ability to decode packets.
The squelch should be left open on the radio when connected to the TNC. The TNC3 will detect the
presence of data on the audio si nal (it uses DCD or Data Carrier Detection). With a closed squelch,
part of a packet preamble will be missed before the squelch on the radio opens. This will prevent
decodin of packets.
The “Battery Saver” option should be disabled. This should have no impact on the life of the battery
when the radio is run with an open squelch.
If you have an inexpensive Chinese radio (Baofen , Wouxun, and many others) with a “Dual Receive”
feature, this must also be disabled. This essentially operates the receiver as a scanner, switchin the
receiver between two frequencies. In general, with these radios, every setting that can be turned of
should be turned off. That is especially true for any squelch tail elimination settings.
Please allow me to editorialize for a moment. The quality of the radio will directly impact the ability of
the TNC to decode packets. Do not connect the TNC3 to a cheap radio and expect miracles. The
system is only as stron as its weakest link.

TNC3 User Guide
Connecting the TNC
Connect the TNC to the HT with both the TNC and the
radio turned off.
Plu the 3.5mm connector into the TNC. Plu the
radio connector (these styles vary) into the radio's
Speaker/Mic connector.
Connecting/Pairing
Detailed instructions for pairin the TNC on Android are below. Instructions for iOS are omitted
because this happens more seamlessly with BLE.
1. Press S1 briefly to turn on TNC. The blue LED will flash slowly.
2. Ensure Bluetooth is enabled on other device.
3. On other device, scan for Bluetooth devices. You should see “TNC3 Mobilinkd”.
4. Connect to “TNC3 Mobilinkd”. The pairin should happen automatically.
Pairing with an Android Device
1. Install the Mobilinkd Confi uration App for Android (available on Goo le Play.)
2. Open the Mobilinkd app.
3. Press S1 briefly to turn on TNC. The blue LED will pulse slowly.
4. Open the app menu and select “Bluetooth settin s”
5. In the Bluetooth settin s menu, select “Pair new device”
6. When you see “TNC3 Mobilinkd” under “Available devices”, select it.
7. After a few seconds, you should see the TNC appear under “Currently connected”.
8. Hit the back button to o back the the Mobilinkd app.

TNC3 User Guide
Configuring the TNC
This section describes the confi uration process usin the Mobilinkd Confi App for Android. The
Mobilinkd Confi App for iOS will be very similar, except the connection and pairin is sli htly
different (a little less intrusive).
This section assumes that you have followed the “Pairin with an Android Device” section above and
have the Mobilinkd TNC confi application runnin . The TNC and radio should be connected, the
TNC should be on, and the radio should still be off at this point.
1. Push the “Connect” button to connect the Mobilinkd TNC Bluetooth device. You will see the
device name and firmware version displayed.
The ima e on the ri ht shows the main menu for the Mobilinkd Confi app. This menu is the startin
point to launch the various screens shown in the documentation below. When you are done with a
certain activity, press the “Close” button to o back to this screen.

TNC3 User Guide
Configuring the Power Settings
You can check the battery level and confi ure the power settin s from the
“Power Settin s” dialo . The TNC3 is fully char ed when it reads
approximately 4.2V (4200mV). The nominal battery volta e is 3.7V. Avoid
operatin the TNC below 3.4V, otherwise erratic behavior may occur.
The TNC may be confi ured to automatically turn itself on when USB power
is present, and automatically turn itself off when USB power is not present.
This is often desirable when usin the TNC in a vehicle. These settin s are
controlled independent of one another.
•To power on when USB power is present, select the “Power on with
USB Power” option.
•To power off when USB power is removed, select the “Power off with
USB Power” option.
The TNC3 will still power on via the Power button when USB power is not
present and “Power off with USB Power” is enabled.
Please be aware: It is a frequent source of confusion for users when they have removed a TNC
normally used in a vehicle and have for otten that these settin are enabled. The TNC will turn itself
on and off when connected/disconnected from USB power.

TNC3 User Guide
Configuring Receive (RX/ nput) Volume
The radio's volume level must be properly adjusted for optimal packet
decodin . Press the “Audio Input Settin s” button.
1. Turn the radio on. If the squelch is set to be open (as you did
when followin the instructions above), you should see the input
volume level on the audio meter.
2. The TNC has the ability to amplify low-level audio inputs
typical of mobile radio data ports. For almost all hand-held
radios, the input ain level should be set to 0.
3. Adjust the volume on the radio until the volume meter li hts up
the ri ht-most level indicator.*
4. If you cannot turn up the volume hi h enou h on the radio to
li ht up the ri ht-most indicator, increase the input ain level.
5. The input twist should typically be set to 6dB when usin an
audio si nal (hand-held speaker output, 1200 baud data output)
and 0dB when usin correlator output (9600 baud data
output).**
6. You can press the “Auto-adjust button” if you are darin . This is best used when connectin to
a mobile radio when the input ain and input twist need to be adjusted.
7. Press the Close button to return to the main menu.
* If your radio uses the volume knob for on/off, it may be helpful to mark on the radio and knob with
the optimal volume settin so it can be set quickly after turnin on the radio.
** The input twist level controls various filter parameters in demodulator. Adjustin the input twist
may chan e the ability (for better or worse) of the demodulator to decode packets.
Configuring Transmit and (TX/Output) Volume
Select the “Audio Output Settin s” button on the main menu to open the
audio output settin s.
Modern ham radios use two different si nalin methods for the Push-to-
Talk (PTT) si nal, which causes the radio to transmit.
Most base stations, mobile ri s (anythin that uses a MiniDIN-6 data
connector) and any radios with a Kenwood-style connector use a
separate PTT line to tri er PTT. This form of PTT si nalin is called
“simplex” since there is one si nal on the line.
Many HTs (Yaesu, Icom, Alinco and others) use the Mic+ line for both
audio and PTT si nalin . This form of PTT si nalin is called
“multiplex” since there are multiple si nals on the same line.
If you don't know which one yours uses, trial and error works to fi ure it
out. Press the Transmit button on the bottom to transmit a test si nal.
You should see the TX indicator on the radio li ht up.