Category Archives: radioamateur

51TNC, review of this multipurpose APRS TNC


2014 12 11 13 46 16


Hi, today I will be doing a very short review about the mystical 51TNC APRS-box which is made in China.   Just add ingredients such as proper data-cable + HT/Rig and you can  turn it into iGate/Digipeater/Tracker or even WX-Station.  

51TNC-box comes with the following set: 

  • 51TNC-box
  • PSU (without the adapter thought)
  • TTL to USB serial Interface
  • RJ45 network-cable
  • Yaesu/Kenwood compatible 6-pin data cable
  • 51TNC-box should also be equipped with bluetooth (for ie aprsdroid), but my model was lacking it! (damn ebay seller) 

Different usage profiles: (link to bigger picture HERE)



2014 12 30 09 23 05

Ive been mostly testing and using it as iGate so got no experience on the Digipeater Side. However I have verified it works nicely on both RX/TX. My current setup is SainSonic GT3MK2 handheld, proper  data-cable from taobao-seller, and the TNC-box.  You can track me on:!call=a%2FOH2FXD-10&timerange=3600&tail=3600

PEOPLE having problem to startup program check that you have atleast .NET framework 4.0 installed! This is depency I noticed just a while ago!

Configuration is done via TCP/IP API and this time I need to say that the software provided is actually quite usable.  Here is some screenshots for the application itself. Please bear in mind that default IP is so you need to configure your LAN / routing for that network too 🙂

Screenshot 2014 12 12 21 20 43

Screenshot 2014 12 12 21 20 51

Screenshot 2014 12 30 10 53 25

Screenshot 2014 12 12 21 21 07


Screenshot 2014 12 12 21 21 15

Screenshot 2014 12 12 21 21 23

Screenshot 2014 12 12 21 21 38

Screenshot 2014 12 12 21 21 44


  • software is ok, its even in english and works quite good
  • box is easy to configure
  • price/quality/usability 


  • bluetooth module missing (ebay sellers fault) , not needing it anyway on own projects
  • cabling (yaesu/kenwood cable) was a bit loose, not good quality
  • missing psu-adapter
Few notices after longer use:
  • when you have SQL open on HT it wont TX (not manual or automatic), my friend oh6elf pointed out that it is important to tune audio level not too high. Im using 16ch kenwood VHF HT now as RX and it is a bit less than “nine a clock”.  You can test this yourself by sending RF test on Beacon page, tune your HT volume until TXD light wont anymore light up when you try to send a packet. When it does not lit anymore tune volume a bit down and repeat. Thanks “ELF” for support 🙂 


Original Site I got my inspiration: 

Software you will need:

Taobao-Seller for the 51TNC box and wouxun/baofeng/kenwood data-cable:

Taobao-agent site Im using:


Original manual: (in chinese):



I noticed that app needs atleast MS .NET Framework 4.0 installed. Try with that and report back to me if possible!
I have mailed to developer and requested more data about the device: howto aquire newer firmware, and howto update it (serial cable included in box should do it).
I have also requested would there be DNS addition to the TCP/IP settings in the future.  



Hear you in the APRS-NET! 73 de OH2FXD-7/9/10  




PS. Here is more pictures for the item if anyone interested ^__^

2014 12 11 13 46 23

2014 12 11 13 46 35


2014 12 11 13 46 44

2014 12 11 13 50 09

2014 12 11 13 50 22

2014 12 11 13 50 49




Into to the Wild with Sainsonic AP510 APRS-tracker



APRS is great amateur radio-based system for sharing tactical information among other ham fellows. For my usage I was looking for a low cost, small and batterywise solution on my hiking trips. I had Kenwood D72 HT earlier, but it ate its battery after 6hours of continuous APRS usage. Not good for longer hiking trips.  Also when travelling in real wilderness without GSM and expensive satellite phones it would be nice for have a faint possibility to send location data via APRS.  Of course I carry my HF QRP station also with me, but thats for the long distance calls and emergency use. 

One of the late nights I came into a Ebay site with AP510 device. Okay, 1Watts output not so good but batterywise, small, and bluetooth connectivity for aprsdroid. Started to sound interesting doesnt it 🙂

This is my review for the AP510 and what Ive noticed with it after playing with it for 3 months. If any questions please drop mail to my mailbox oh2fxd (a) 


 Here is the most interesting specs first:

–  Price range 100-150eur (including shipping/handling)

– SIRF4 GPS module (very nice)

– Based on AVR Mega 64 SCM 

– VHF Module, 1W output.

– Stock VHF-antenna

– 3,300mAh battery Will last about 28-36 hours with 20second beacon interval. Of course will last longer when you wide the interval, 10minutes could be okay for hiking as you move slow anyways.

– 18B20 Temperature Sensor (-40C ~ +99C) How cool! This is measured inside the machine though, if you want to measure outside temperature you need to modify your tracker.

– microsd slot supports 4G FAT16/FAT32 card for KML format internal track logging (not yet tested)

– Bluetooth connectivity for IE aprsdroid 



Configure app, Update app and firmware hex:

MsComm32.ocx files:



Update AP510 on windows (or virtual win-environment). Examples are from Win 7.  You should do this first as youre firmware is older than the application pack my blog is sharing. So first upgrade, then configure! .

  •  Plug cable and install Prolific drivers.
  • Shutdown tracker, and connect it to programming cable.
  • Open up the update software –> File -> Load –> 2014008(RX free)AVRT5.hex –> Operate —> Download —> Press Power-On button on AP510 until process is complete on the application.  If the update fails, repeat. 
  • Restart tracker and you should be good to go for next step.
Things to bear in mind with update application:
  • On Windows 7 update software may need MSComm32.ocx files (for serial communication). You can download them here:
  • Unzip and copy to: C: \ Windows \ system32 folder, I installed 64-bit Win7 system so copied to  C:\Windows\sysWOW64 folder
  • open cmd-promt, execute code regsvr32 C:\Windows\system32\MSComm32.ocx  ( or C: \ Windows sysWOW64\MSComm32.ocx ) 
  • This should promt that register is success. If not try running cmd-prompt as administrator.

Setup 1448000fourdigits

UPDATE: Configure AP510 on windows/linux/osx using CHIRP, for this you need daily-build as AP510 support was released 13 days ago!

UPDATE2: I have successfully tested on windows 7 chirp daily 20122014 build and it works nice! Pictures in end of this post 🙂

OR: Configure AP510 on windows using the manufacturer app (or virtual win-environment). Examples are from Win 7.

  • Plug cable and Install Prolific drivers (if not done allready)
  • Shutdown tracker, and connect it to programming cable.
  • Open AP510 configure application, select proper com port and read configuration
  • Press AP510 power-on button until you hear beep – release and read should be succesfull
  • Modify your settings and write back.

Things to bear in mind with configure application:
  • callsign needs 6 digits, use space-key to fill up the “gap”
  • frequency need for digits after comma “.” ie.  144.8000
  • if you have problems to write settings to AP510 please change keyboard and locality to US (I know this is weirdest thing)
  • price
  • form-factor


  • antenna connector is loose, you cant tighten it up very well with certain antennas.
  • software is bugged, but improving!
  • installing software can be pain in the ***
  • 1Watt is not much. 
  • Antenna could be better, changed mine to GT3MK2 antenna which seems to perform a bit petter. For hiking maybe halfwave dipole in your backpack? 
  • Software needs to be more userfriendly or product wont sell. (as people likes todo things in easy way)
  • Upgradeable LCD for heading etc (ive seen some projects for this allready)
  • Better support for the product, now I dont know any.


 APRS information:


Yahoo groups:

Video for configure & update:

Seller (ebay):

Seller (taobao):

no link provided, you can actually buy this a bit cheaper from China via taobao and using taobao-agents to make a purchase. I will do another blog entry about using such agent-service.

Japanese site for newest files (use google translate if needed):


UPDATE2:  Some pictures of awesome Chirp support for AP510!

Screenshot 2014 12 21 15 54 59


Screenshot 2014 12 21 15 54 14


Screenshot 2014 12 21 15 54 31


Screenshot 2014 12 21 15 54 39


Screenshot 2014 12 21 15 54 48


Using AP510 with Xastir via BT serial interface (OSX tested):




Thanks for feedback kd7lxl, oh2khz!  & 73 to all you ham-bros and sisters out there! ^___^


Building a complete ADSB receiver unit from A to Z


Good day Sir! Reporting for duty! 🙂 Today Im going to explain howto build complete ADSB-receiver unit using various of projects. This includes to build your own reception antenna, reflashing android based “mini-pc” to linux, installing rtlsdr stick to it and various of apps. This project consist of following parts:

  • RTLSDR (cheap DVB-T stick used as SDR-receiver)
  • Rikomagic MK802IV (android based computer turned to Linux box)
  • Homebrew 1090Mhz 1/4 wave GP-antenna
  • Homebrew casing for the whole setup
For getting MK802IV & RTLSDR you can buy em from ebay for decent price. Links provided:
For information what is ADSB you can find from this wiki-link:
As in radioamateur hobby we will start with the most important part first: Antenna.  It is important to use an antenna which has optimal match for the frequency you are going to use it. So forget the dvb-t antenna which comes within the RTLSDR stick and concentrate on making a better antenna yourself. For this project you will need:
  • either good coaxial cable (rg58/rg213)or soldering sticks(copper)
  • UHF- or N-based chassis connector.
Antenna build instructions done by Atouk:
1/4 GP-antenna is very effective antenna for this kind of setup (and small). If you feel adventurous you can also start building antennas like Collinear. I even tried a collinear antenna but it failed to work properly as it seems that this type of antenna needs a lot of “air” to be effective ie. installing on the roof. So back I were into the drawing board and my 1/4 wave GP-antenna.  I improved the reception by adding 4 more groundplane sticks (not seen on pic) and as they were leftovers from the failed colliniear antenna project they were 196mm long. I did not cut them back to original lenght for 1/4 as the antenna seemed to work much better than every antenna Ive built earlier for ADSB-reception.
Screenshot 2013 10 15 18 03 57
Next its time to grab your MK802IV and start configuring Linux (picuntu) on it! This beauty is equipped with quad core arm cpu, 2GB ram, 8GB flash mem. Ability to mount microsd card up to 32GB and by default runs Android. This is going to change thought as we need Linux OS for better hacking 🙂
Rockchip Rk3188 Quad Core Cortex A9 Android 4 2 Mini PC 2g DDR 8g Flash Blue Tooth WiFi TF Card 1080P Flash11 1 RKM MK802IV 

Download RKBATCHTOOL from rikomagic and install drivers from url Check part: MK802IV Mini Pc and correct serial number from your stick!

Download rest of the stuff gathered from here (720p kernel and rkandroidtool):


Unzip both zips and navigate to RKBATCHTOOL folder ie: IV_AP6210_20130905_1080P –> Batch tool+driver1 v 1.7  –> driver –> Start DriverInstall.exe 

After installing the drivers on your pc.  Connect microusb to your sticks OTG-port (while stick is connected to TV and running)

On Android OS -> go to settings -> USB -> Connect to PC [X] -> Windows should recognize device and install Riko USB Mas storage drivers.

On PC start RKANDROIDTOOL and press switch.  Windows should be able to recognize the new driver and install it. Voila now you are in android loader! 🙂  


For first task is to Erase IDB -> Erase IDB Button


Then pickup the necessary files downloaded from dropbox and push RUN.


Loader/parameter/kernel/boot/system are the needed files for working firmware.


image should be created and reflashed to a stick.  reboot after it is done and I wish you luck! 🙂


Screenshot 2013 10 15 16 04 51


After the image is flashed stick will be rebooted and you can login user is : linuxium  p:  p


At this time I added a new user, new password, added new user to /etc/sudoers for easier access.


More nfo:


Now it is time to configure WiFi-access on your fresh Picuntu install so you can actually plug the stick off from TV.
Check what networks (SSID) available:
iwlist wlan0 scan 
Edit your interface reference file:
vi /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)

auto lo
iface lo inet loopback
auto wlan0
iface wlan0 inet dhcp
wpa-ssid *************
wpa-psk *************

Restart network:
sudo /etc/init.d/networking restart 
After installing Linux on the RikoMagic MK802IV stick its time to do some basic confguration and install packages:
apt-get install screen nc socat yourfavouriteditor 

After building the antenna, installing Linux and putting all together its time to install some applications for doing the ADSB-data dumping:

  • Kalibrate-RTL
  • Dump1090
First install some depencies needed for the builds:
sudo apt-get install git cmake libusb-1.0 libusb-1.0-dev autoconf libfftw3-dev

Download needed software via git:
For a starter make sure you are in example your $HOME directory
git clone git://
git clone git://
Compile rtl-sdr:
cd rtl-sdr/
mkdir build
cd build
sudo make install
sudo ldconfig
sudo cp ../rtl-sdr.rules /etc/udev/rules.d/

At this point replug RTLSDR stick!
Compile kalibrate-rtl:
autoreconf -i
cd kalibrate-rtl/
git checkout arm_memory
sudo make install
Compile dump1090:
cd dump1090/
After compiles are finished it is time to check some parameters and put then into your adsb-rx script:
(at this point it is good to hook up your antenna to rtlsdr stick)
run rtl_test -t first to check max gain for your stick (write it down)
example here:

Found 1 device(s):
0: ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Supported gain values (29): 0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4 28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
No E4000 tuner found, aborting.

run kalibrate_rtl to check ppm correction:
kal -s GSM900
kal -c 100 (pick one of channels you got ie. ch100) 
example here:

iffe@goobie:~$ kal -s GSM900
Found 1 device(s):
0: ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Scanning for GSM-900 base stations.
chan: 6 (936.2MHz + 1.177kHz) power: 235085.65
chan: 19 (938.8MHz + 2.352kHz) power: 103046.92
chan: 21 (939.2MHz + 1.752kHz) power: 746103.29
chan: 25 (940.0MHz + 2.333kHz) power: 95518.88
chan: 28 (940.6MHz + 3.229kHz) power: 159665.01
chan: 32 (941.4MHz – 30.576kHz) power: 435084.78
chan: 39 (942.8MHz + 3.019kHz) power: 182267.86
chan: 49 (944.8MHz + 2.896kHz) power: 161003.24
chan: 76 (950.2MHz + 4.080kHz) power: 780821.91
chan: 80 (951.0MHz + 5.363kHz) power: 593942.56
chan: 113 (957.6MHz + 10.826kHz) power: 271638.56

I will pickup the highest channel found on scan:

iffe@goobie:~$ kal -c 113
Found 1 device(s):
0: ezcap USB 2.0 DVB-T/DAB/FM dongle

Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle
Found Rafael Micro R820T tuner
Exact sample rate is: 270833.002142 Hz
kal: Calculating clock frequency offset.
Using GSM-900 channel 113 (957.6MHz)
average [min, max] (range, stddev)
+ 12.301kHz [12251, 12350] (98, 26.953159)
overruns: 0
not found: 1
average absolute error: -12.846 ppm

write down the ppm value!
Now after you have finished these challenging tasks it is time to start dumping some ADSB data:
Run dump1090
cd $HOME/dump1090/
screen ./dump1090 –gain 49.6 –ppm –12.846 –net –interactive –agressive
You can also create startup script for future use ie:
vi/joe/pico/nano(your favourite editor)  $HOME/adsb-rx
cd /home/$USER/dump1090
screen ./dump1090 –gain 49.6 –ppm –9.087 –net –interactive –aggressive
chmod + $HOME/adsb-rx
cd $HOME
Now you can access your webserver by localhost or via your LAN when you know your host IP-address (localhost:8080 lanip:8080). Make sure 
firewall is not blocking your access to tcp/8080 port.
Remember you can also direct ADSB data to external hub or ie. Virtual Radar run by win32/64 or another Linux running VR via mono.  Also there may be option to 
share data to PlaneFinder in future 🙂
Here is some example commands:
unstable stuff (forking may cause problem)
socat TCP4:localhost:30002, fork TCP4:targethost:30001
better but nc dies if no connection:
nc localhost 30002 | nc targethost 30001

You can check my server on

For the last I saved up some installation pictures how I did case mod for the sdr+mk802+antenna for ultimate portable adsb unit 🙂 Comments welcome! I will try to keep this blog entry updated more often as my fine tuning is fully completed 🙂





Screenshot 2013 10 15 18 37 29


UPDATE:  (not directly related to adsb receiver unit) but I played along with Wine on OSX + adsbscope and here is current range map I got for today!




Have fun and 73 de OH2FXD 🙂 You can contact me ifreq@FREENODE ##RTLSDR



ft-950 and 32usd band-scope project – see what you hear

 First.. thanks for this site (and various of others) to give me idea to start playing with cheap bandscope project with rtlsdr-stick (dvb-t)

I have been playing with rtlsdr for quite long, and after aquiring a Yaesu FT-950 I was ofcourse going through what I can do with the rig and accessories.  Then after some lucky google search I came to tarapippo’s site and got the idea to test bandscope myself.

Here is what you need in general:

rtlsdr compliant dvb-t stick 10 euro  in ebay like here :

bnc to mcx adapter 9 euro in ebay like here:

tmp to bnc adapter 5 euro +shipping from funk amateur:




  1. start to remove many many screws from the bottom of the ft-950
  2. all screws are off and time to flip cover open!
  3. there ya go, now to locate scope-plug
  4. scope-plug located, which states clearly “scope” and is connected to 50ohm dummy. remove the dummy.
  5. took the dummy off from the plug and taped it in here.
  6. now spot hole in the left upcorner from where you will insert the tmp->bnc cable.
  7. mp-adapter looks like this. I had to squeeze it a bit to get it through the rigs back panel ventilation holes.
  8. then comes the “hard” part. push tmp cable toward the hole in left up corner and use pliers to pick it up from the hole.
  9. then connect it to the scope-plug and youre done! 🙂


After that you can connect the bnc-adapter to bnc-mcx and mcx to dvb-t stick and to your computer.  

Then you can startup your favourite SDR-software, tune to 69MHz and start catching signals on HF. Some SDR software (like HDSDR)

supports also CAT-controlling.  There is 3 images in the bottom of this blog, and listed in order 15m/digi ,  20m/ssb, 40m/ssb.   73 de OH2FXD ! 🙂










Power me UP Mr. Scotty! – FT-817ND power cabling

Here is my power cable setup for 817, in the picture missing 5000mah 4S lipo which power out 16.7V max so need voltage regulator. Starting from down to up:


#1 plug to rig 

#2 fuse cable

#3 wattmeter

#4 12VDC ubec (voltage regulator)


Connectors are xt60 which can handle atleast up to 65A continuous! All the special parts are from RC-hobby and are much cheaper than any HAM spesified part-sellers. I have bought all my stuff from  As you can see the cables are made as “modules” so you can decide will you run the cable with wattmeter, ubec, or even fuse.  If any questions im happy to answer 🙂


73 de OH2FXD


IMG 2711


Parts list:



XT60 connectors:


Building a HAM-DRONE

HAM-DRONE v 0.1x

Mission:  Listen, Transmit and Inspect

Target: Sky, alt. max 150m

Estimate time of finished project :  03/2013

IDEA: To be used for inspecting antennas, longwire tests, analyzers.

Codename: He-Who-Must-Not-Be-Named and You-Know-Who

Parts: (mainly thanks to HobbyKing!)

Flight Controller: Crius All In One Pro V1.0 ebay

Servos: 4* pcs  NTM 2826 1200kv

Servo fitting kits:

Propellers: 8x4R

Frame: x666

Transmitter: Spektrum DX7 used

Receiver: AR7000 used

Turnigy Accucel-6 Charger:

Battery: 2x 5000mah turnigy 4S

ESC: Turnigy plush 30A:

ESC: turnigy programming card:

GPS: Crius CN-06  ebay

12 in 1usb simulator dongle ebay

gopro craddle:

servos for craddle:

xt60 connectors:

xt60 harness:

polymax connectors:





Mission Planner

Simulator software ie. Phoenix


D2-D13 = motor connections

AR7K need to be on 90degree angle


MegapirateNG+Crius programming:

DX7 spesific:


Flight control parts and the x666 frame.


More part pictures.


Installing the “bed” for the Crius All In One flight Controller


FC installed.   


Prepping up the frame and LG (landing gear)         


Side of the LG’s   




LG installed.          


Frame built, thought missing few aluminium spacers, so res of the LG’s will be connected later.        


Crius All In One       


He-Who-Must-Not-Be-Named and You-Know-Who is Alive!      


Starting up Mission Planner after succesfull flash of the MegaPirateNG.


OK ready to go.. wait! wheres the motors          


 DX7 controller arrived and some extra items hooray!


 Landing Gear finished with some homebrew components :–) (bolts and plastic tubes)          


Crius ALL-IN-ONE V1.0 in all its might!




Wiring the Crius CN-06 V2.0 GPS module:

GPS-module has 4pin (black/gnd, green/rx/, yellow/tx, red/vcc)

USE i2c port to get power (pin3/5V, pin4/gnd)

USE Serial Port to get TX/RX for GPS (pin3/tx2 –> wire green/RX, pin4/rx2 –> wire yellow/TX from gps-module)

Here is some pictures with the gps-module +installation:



GPS is on, but no fix yet! Will test it outside tomorrow



UPDATE: And we have the FIX! 🙂


Jewellery Box case mod for GPS


Madlab Industries protective casing is way over COOL aspect!



battery installed + voltage buzzers ! 🙂



Got today the PWR wired up and messed up with the receiver! 🙂 It starts to look like insect!

IMG 2743


IMG 2744




IMG 2751



To be continued.. 73 de OH2FXD/QUAD


Yaesu FT-250e – Its Rugged Baby!

Some weird radio-bug bit me on the last Field Day event and I was destined to get me a new VHF handheld.  My ham radio friend Harri (OH7HL) had Yaesu VX-150 (premodel of FT-250e) and instantly when I got home I started to look same kind of rugged and simplified radio. To my luck Yaesu had pushed in the market newer model which had a bit stronger audio output and added some features related to memory banks. I was ofcourse straight away hooking it up to the computer to notice only software available is something you pay for.  Earlier paying for ft-60, ft-817nd, ft-270 software from same coder I decided that I wont waste my bucks for piece of software and try to do it old way and manual program I did.  Took me up 2 minutes to configure handheld memory banks with simplex and repeater information, naming them would take a bit longer hi.

Here is some info I leeched on Yaesu’s webpage:

– 0.5/2/5W VHF handheld
– 1400 mAh battery
– 700mW of Loud Audio
– Wide/Narrow selection
– Nine DTMF Auto-dialer memories
– Two Front Panel programmable keys
– RF Squelch
– Battery Voltage Display
– TX Deviation Level (5 kHz or 2.5 kHz)
– Transmit Time-out Timer and Automatic Power-Off
– AR- Water resistant case construction
– Automatic Repeater Shift
– Memory-Only operating
– Scanning Mode: VFO / Memory / PMS / Dual Watch
– Busy Channel Lock-out
– ARTS (Auto-range Transponding System)

For short review this is very nice one band handheld to own if you like simple, made to last type design. One thing I would myself do a bit better is the back light on the screen, it is very very dim. Maybe future brings some modification suggestions who knows hi.

More info found on Yaesu’s site:

73 de OH2FXD