Monthly Archives: February 2014

Txfactor Regular Internet TV Features For Amateur Radio

 

A new Internet TV program has been launched this month (Feb 2014). It provides insight and News from the world of Amateur Radio.

The series of programs will be accessible from

http://www.txfilms.co.uk/txfactor/ or on youtube

The company TX Films has been set up to produce lively and informative content for specialist interests including leisure, science and technology.

The program is produced by radio amateurs for radio amateurs.

In the first episode the presenter visits the Marconi Centre which is also home to Poldhu Amateur Radio Club. Here we learn about Marconi’s transatlantic experiments using spark transmitters and coherers.

Also find out about the challenges of working summits on the air and how a 2 metre repeater is run at the Norman Lokyer observatory and radio station GB2NLO.

 

 

 

 

 

Cube Sat

Listening to Funcube 1

Initial Attempts with Funcube 1

I have been interested in Satellites for a while and have heard some transmissions from the ISS in the past.

I decided I would investigate the New Funcube 1 (AO-73)
which has 5 or 6 passes a day which can be heard in the UK.

See link for predictions

http://www.n2yo.com/passes/?s=39417

The satellite downlink is on 145.960 during evening passes
BSPK Telemetry is on 145.935

I have monitored tranmissions with a vertical colinea at about 12 meters above ground. To get more signal from near overhead passes I have installed a loop antenna about 1 meter above ground level.
This is simply a loop of coax almost two meters long supported by
canes stuck into the lawn, a very temporary affair, its fed via 40 cms. (1/4 wave) of 75 ohm satellite impedance to transform the loop impedance of around 100 ohms to 50 ohms.
The loop is horizontal and will give better results for horizontally polarised signals than the vertical.
I am not sure what polarity we should expect from the Funcube but suffice to say it is likely to vary.

On test the horizontal loop supplied some interesting results.
Indeed it was possible to hear several stations calling CQ on the evening passes on both antennas with the loop sometimes providing the stronger signal. Often the S meter on the IC910 did not register but calls could be clearly heard including Germany Spain and the UK.

Various other signals could also be heard on the horizontal loop which were poor or non existant on the vertical they do not drift in frequency and can be received for long periods of time so not from satellites.
I don’t know the source of these signals or even if they are images from out of band signals. There is one at 145.942 USB
S5 on the metre sounds like a burst of very fast CW every second.
At times this is a continuous carrier.

I have installed .net V4 and the Funcube Dashboard software

see

http://funcubetest2.files.wordpress.com/2013/11/funcube-dashboard-install-ops-guidance-notes-release-1-2.pdf

The software is working and can read the downloaded test file,
however as yet I have been unable to match the output from the IC910 8 pin Aux socket to the souncard.

As far as the transponder goes I may need to make another antenna for the 70 cms. uplink.
The frequency for this is 435.140 and the transponder is set up as inverting. This means that the uplink will need to be transmitted on LSB for USB downlink and tuning up on the receive side corresponds to tuning down on transmit.

Raspberry Pi

Xastir On The Raspberry Pi

 

Installing Xastir

Xastir allows you to sent upa location server for your internet connected Pi to show the location of your station on aprs.fi via the APRS network.

Method

1. Get image file
eg
2014-mm-dd-wheezy-raspbian.zip and unzip to get
2014-mm-dd-wheezy-raspbian.img

2. Download and unzip
win32diskimager-binary.zip
3. From the downloaded files in 2 run Win32DiskImager.exe Select the correct image file and destination which will be the raspberry pi’s SD card

4. If a config file is available to work with the screen in use with the correct resolution copy this onto the card.

5. Insert the card and connect monitor, keyboard and mouse.
Insert the power connector.

The raspberry-pi should now boot into the configuration utilty.
raspi-config see http://elinux.org/RPi_raspi-config for details

In the UK the correct Locale is default so you only need to

EXPAND-ROOTFS – Expand Root Partition to Fill SD Card  if the image is smaller than the card you are using. Over time you can then add more data and applcations to make more use of the card.

6. login as pi user to shutdown the system after exiting raspi-config

Plug in the network cable and restart this time an address should be assigned, I checked this in the routers client list.

7. Since this is a new build it requires updating.
sudo apt-get update

Followed by:
sudo apt-get upgrade if you want to look for newer packages

Now’s also a good time to make sure the who Linux distribution is up-to-date. You can do this now, or later (it may take a while). Again make sure you have an internet connection and run:

sudo apt-get dist-upgrade.

I omitted this to save time as the download is recent. When running apt-get you may be prompted with a continue Y/N.  Just type Y and return.

8. sudo apt-get install gdebi
This installer is useful for installing packages from the gui

if required later.
9. sudo apt-get install Xastir this installs Xastir

10 startx start the gui and then locate Xstir and run it.

11 Follow the configuration details as in

http://www.xastir.org/wiki/Configuring_Xastir