A tribute to UO-11

In just six months time engineers at the University of Surrey developed, built and launched on 01-03-1984 UoSAT-2 as a piggyback payload aboard a U.S. Thor-Delta rocket carrying the LANDSAT-D earth observation satellite from Vandenberg Air Force base in the orbit.

With 70 kg was UoSAT-2, the first satellite with advanced digital “store-and-forward (email)”


UO-11 is not operative but sometimes, when it's on sunlight it begin to transmit the telemetry on 145.826 Mhz.


Here it's possible to see the update status of this satellite along many others:


Oscar satellite status


This is a audio recording that I've personally made of the UO-11 telemetry sound:


UO-11 sound on soundcloud

The Fredbox

I really like this post and the idea to build a Fredbox in the future:

http://www.vk2zay.net/article/123

So this post only a memo on the site that speak about it.

ISS SSTV transmissions

I've get it...yess

QIKcom-1 APRS Satellite

 A fresh info from Bob, WB4aPR




APRS Satellite operators:

http://aprs.org/qikcom-1.html


We are delivering our next APRS satellite (QIKcom-1) next week and it will
have a mission life of maybe 6 months.



It is a very quick reaction short fuse opportunity so we are simply going
to fly an APRS digipeater (TinyTrack4) supporting the three digipeater
aliases of ARISS, APRSAT and WIDEn-N but it will operate at 4 Watts RF
power and be easily heard on any HT..



It has no other CPU on board and so it flies with only the fixed settings
set before launch.



But we do have an A/B switch which can be used to switch between two bank
settings.

I just cannot think of any neat must-do ideas for how to use the other bank
settings.



The host spacecraft has plenty of power, so there is no need for low power
options… (they can simply turn us off if needed).  Telemetry is a boring
Volts, current, and two internal temps.  The settings in bank 0 are now:



DIGIPEATER:  ON

ALIASES:          ARISS, APRSAT, WIDEn-N

BTEXT:              USNA-W3ADO APRS Satellite every 2 minutes

TELEMETRY:   every 1 minute.



I just cannot think of any use for a separate bank settings?



If you have ideas of how to use the A/B settings let me know.



Bob, WB4aPR

Mobilinkd TNC2 on Ubuntu Linux

First step let Ubuntu to see the modem

My bluetooth usb adapter is an old emtec one, Ubuntu 14.04 does recognize it immediately after plug-in in the usb port.

Then I've switched on Mobilinkd TNC2, the blue led started to flash.

The first problem is that the enclosed Ubuntu bluetooth manager does not works with a Bluetooth serial module of the Mobilinkd TNC.

As I try to configure it with the bluetooth manager it request to set a random password on the modem that is not possible.

So install the blueman bluetooth manager:

sudo apt-get install blueman.

Now start blueman and magically it's possible to pair the Mobilinkd TNC and see it as a rf serial /def/rfcomm0

Try to see if the modem is accessible from the serial port with a terminal, like moserial.

The serial port speed should be 115200.

For example in moserial I saw:

== BeRTOS AVR/Mobilinkd TNC2
== Version 2.0.1.571
== Voltage: 4026mV
== Starting.

Second step AX.25 settings

First install the necessary AX.25 packages:


# sudo apt-get install ax25-tools# sudo apt-get install ax25-apps

Then, configure your AX.25 ports to allow you to access the TNC.

sudo vi  /etc/ax25/axports:

# /etc/ax25/axports

#

# The format of this file is:

#

# name callsign speed paclen window description

#

packet0     IN3AQK-9         115200  255    2      144.900 MHz (1200 bps) Packet

Pay attention no empty lines are allowed!

Then connect the AX.25 packet0 port to the tnc with the command:

sudo kissattach /dev/rfcomm0 packet0 10.0.1.1

The result is:

AX.25 port packet0 bound to device ax0

With ifconfig you could see a new ax25 port with the ip 10.0.1.1

Then it's time to call for example:

axcall packet0  IR3DG


Now its, possible to point Xastir to the just created port packet0

To be continued

APRS on QRP Portable

In addition to having a strong passion in QRP activity, especially in portable, have always been passionate about economic digital technology, Such as packet radio, APRS and TNC, NO D-Star, NO DMR.

In the 90s my packet radio station  and packet radio satellite gears has been continuously on for years, it was my internet at zero cost.

During my QRP HF portable activities, I had the necessity to have a wireless data communication system, not based on cellular technology.
Also because often where I go there is no cellular coverage while the packet-aprs system works.

In addition as software developer work I have developed wireless tracking systems, very similar to APRS.

I have used for some time the tinitrack4, both as aprs and kiss modem.
It works fine, but had some problems, such as:

Too sensibile to the RF emitted by the transmitter
Too many connectors
External power supply.
Casino to connect to Android.

Last Monday I stumbled on this project:

http://www.mobilinkd.com/

http://store.mobilinkd.com/

Bought immediately and arrived yesterday with DHL.


It is a packet radio kiss modem.
In practice it means that it is a stupid modem, not a real or TNC APRS one.
 
Therefore it requires an external system such as Android.

The modem is very small, it attaches directly behind RTX handheld with a rubber band.

It has an internal lithium battery that allows 48 hours of work.

Beautiful thing is that the serial port is bluetooth and then zero cables except the one with the RTX.

The system do NOT works with iOS systems, because they do not have support of Serial over Bluetooth.

It interfaces seamlessly with APRSDroid and BTTerm for Android, but it also goes with APRS clients and  Terminals for Windows and Linux.

The configuration is done in 5 minutes with a simple program for Android or Windows.

This system can be seen on www.aprs.fi, I can indicate on which frequency are QRV on HF during my activations.

Can I send sota spots , read the cluster and even send an email.


The modem is the little box behind the wouxung

APRS data on my tablet over bluetooth 

Sota Omini di Pietra 2000 metri I/AA-307

Oggi ho fatto una bella attivazione Sota alla cima Omini di Pietra 2000 metri I/AA-307

Aggiornamento, pare che ora la cima non sia più valida come referenza Sota

50 collegamenti circa in 20 Metri, quando mi hanno spottato su sota.uk si è creato un pileup che ho fatto fatica a gestire.

Particolarità dell'attivazione:

Sono uscito con stilo mfj da 5 metri e compressore di dinamica fukamateur.de.

Risultati eccellenti, entrambe le soluzioni sono state vincenti

Ciao e 73 de IN3AQK

Qui sotto qualche foto.

Come vedete sono circondato dagli omini di pietra

Gli omini di Pietra

The Shack of IN3AQK

The equipment

73 de IN3AQK

Submersible buoy

Lancio sperimentale Palloni con trasmettitore RTTY

Da anni seguo il gruppo inglese ukhas che ha messo a punto un eccezionale insieme di tool per il tracking in diretta la cui punta dell'iceberg è la mappa online che mostra posizione del pallone e dati telemetrici, nonchè le stazioni in ascolto.
http://spacenear.us/tracker/

Sinteticamente funziona così:
pallone -> stazioni riceventi (anche multiple, potenzialmente infinite) -> decoder -> upload su server -> dati raw -> mappe, grafici, etc

Quindi per chi volesse tracciarci dal Nord Italia deve avere:
* un scanner funzionante sui 434 MHz SSB o una chiavetta SDR
* una antenna potenzialmente adatta per quella frequenza
* il decoder DL-FLDIGI che è una versione modificata del famoso software per radioamatori fldigi
* una connessione internet

Qui la guida in inglese:
http://ukhas.org.uk/guides:tracking_guide

Vi invito quindi a provare ad installare DL-FLDIGI. Se lo configurate a dovere anche con le vostre coordinate dovrebbe apparire la vostra antenna sulla mappa di cui sopra.
http://ukhas.org.uk/projects:dl-fldigi

10 GHZ WBFM

Log dei miei esperimenti sulla banda dei 3 cm, 10 ghz, in modalità WBFM

Il ricetrasmettitore è un Nuova Elettronica LX346, la cavità ha 10 mw

Antenna a tromba auto-costruita con guadagno di circa 10 mw

Antenna a tromba con guadagno stimato di 20 DB

In fondo si vede la cavità GunnPlexer

Sul lato destro si vede la cavità con il GunnPlexer

Particolare del ricetrasmettitore

Vista frontale ricetrasmettitore

Portante ricevuta con RTL-SDR

Il tono modulato

Radiomarelli RD 225, prima esperienza con le radio a valvole

Ho deciso di imparare qualcosa sulle valvole termoioniche e quindi per spendere poco ho preso questo ricevitore in Onde Media Radiomarelli modello RD 225.

Apparentemente funzionante, qualcosa si riceve ma scricchiola un po

Rd 225 frontale

Le valvole sono 5, una di queste è una raddrizzatrice.
No ha il trasformatore classico ma un autotrasformatore, quindi la ground del circuito è connessa alla rete elettrica, bisogna stare attenti!!

RD 225 Aperta