Rocode >> Hobbies >> Amateur Radio

Amateur Radio Experimentation

This page details my experimentation with the local Amateur Radio broadcasts.
It specifically details my IT related amateur radio interests.

Further details regarding my other interests in amateur radio and telecommunications may be found on my personal web site communications interests page.

Here is a brief menu of what is detailed below.

TV Antenna Distribution to receive VK3RTV.
rocode.com/amateurradio/#TVAntenna

Watching VK3RTV1 and VK3RTV2 using Mythbuntu Linux.
rocode.com/amateurradio/#MythTV

My VK3RTV ON or OFF Air checker and Elvin notification.
rocode.com/amateurradio/#AvisATV

Repair of Mac TV Dongle.
rocode.com/amateurradio/#USBRepair

Watching VK3RTV1 and VK3RTV2 using a DGTEC set top box.
rocode.com/amateurradio/#DGTEC

May Raspberry Pi be used with VK3RTV.
rocode.com/amateurradio/#RaspberryPi

Here are some external Amateur Radio links.

The Wireless Institute of Australia.
http://www.wia.org.au/

Melbourne Digital Amateur Television.
http://www.vk3rtv.com/

Amateur Logic.TV
http://www.amateurlogic.tv/

Ham Nation
http://twit.tv/hn

Jaycar Electronics (Retail Store).
http://www.jaycar.com.au/

Radio Parts Group (Retail Store).
http://www.radioparts.com.au/

TV Antenna Distribution

I have a rather complex antenna wiring layout from the antenna socket to the many DVB-T appliances. I installed a VHF and UHF diplexer between the antenna socket and the first f-type splitter. With only the UHF side of the diplexer connected the strong VHF signals are attenuated before being put through the two amplified splitters.

TV Antenna Wiring

I connect my DVB-T appliances using RG-6 coaxial cable from my antenna splitters. There is no replacement from the usage of decent coaxial cable to give the maximum signal available from VK3RTV at your receiver. The better cable allows you to have more room for losses in your antenna connections and still receiver the repeater. The digital signal is either received succesfully or you will not be able to tune your receiver and need more signal.

I use two antenna splitters. The first is a 4 Way TV VCR Antenna Signal Amplifier Booster Splitter from Radioparts for $55. The second is a 4 Way TV VCR Antenna Signal Amplifier Booster Splitter from ebay for $13.

Antenna Splitters

TIP: Without the diplexer inserted before the amplified antenna splitters I was unable to receiver VK3RTV after the second splitter. It appears that the strong VHF channels (SEVEN, NINE, TEN, ABC) would interfere with the signals going through the splitters. My set top box would complain that the Digital ATV signal had to much noise and it could not decode the repeater.

Watching VK3RTV1 and VK3RTV2 using Mythbuntu Linux

The Melbourne Digital Amateur Television repeater is called VK3RTV.
http://www.vk3rtv.com/
The VK3RTV official website contains live streaming of the repeater.

The repeater is configured with 2 multiplexed DVB-T digital television channels being VK3RTV1 and VK3RTV2.

The ATV repeater uses the frequency of 446.5MHz which is not a standard Australian channel. As a result many digital tuners may not support this frequency. Many tuners skip from channel 12 to channel 27 and may not have manual tuning. VK3RTV transmits at 446.5 which is around channel 16.

Here are the transponder details for VK3RTV here in Melbourne, Australia. Included in my Melbourne_Transponders_File.

Transponder settings for VK3RTV

Use the scan command, when VK3RTV is on-air, to collect the channel information for use in tuning Mythbuntu.

The following data was generated by issuing this scan command.

scan Melbourne_Transponders_File > channels.conf

Scan report for VK3RTV

channels.conf for VK3RTV

The following screencast shows how to configure Mythbuntu to receive VK3RTV1 and VK3RTV2. I tune all freeview channels as I use the channels.conf file with the channels from all 7 Melbourne transponders.

Configuring Mythbuntu for reception of VK3RTV

I purchased a Leadtek Winfast DTV Dongle Gold USB TV Tuner from mwave.com.au for $40.

The Leadtek Winfast DTV Dongle Gold USB TV Tuner box comes with Windows software but this is unable to tune the frequency of VK3RTV. However, using Mythbuntu Linux, the WinFast DTV Dongle can successfully decode VK3RTV1 and VK3RTV2.

Leadtek Winfast DTV Dongle Gold USB TV Tuner

The signal strength of the ATV repeater is very low and not all the DVB-T receivers will lock on the repeater. I have tried a few other DVB-T dongles without success.

I connected a RG-6 coaxial cable from my antenna splitter to the Winfast DVT Dongle.

Within MythTV RTV1 and RTV2 do not have a logical channel numbers, as shown in the above screencast, I manually enter 350 and 351 to match my set top box.

Here are a number of screenshots of local amateur television stations as received via the VK3RTV repeater using Mythbuntu Linux.

VK3RTV Repeater Test Card	VK3RTV Repeater Signal Strength
VK3DQ	VK3KHB
VK3WWW	VK3KQ
VK3BFG	VK3ATV

Further details about my installation of Mythbuntu may be found on my ASRock Demonstration page.

VK3RTV is ON or OFF Air Checker

I have connected DVB-T television to my computer network and check when VK3RTV the Melbourne Digital Amateur Television repeater is switched on or off.

I connect my Ubuntu Linux PC, running as a Zental Router, to the roof top antenna using a usb Leadtek Winfast DTV Dongle Gold USB TV Tuner from cpl.com.au for $28. It connects directly to a USB port on the ASUS Eeebox PC. Some detailed instructions on installation may be found on LinuxTV.org here. I was required to manually download a firmware file to enable the dongle.

I have found this to be the best dongle to receiver VK3RTV. I have used other dongles including Kaiser Bass TVStick and Pinacle PCTV nanoStick. They receive the Freeview networks okay but have less success with the local Amateur TV repeater.

TIP: The supplied Microsoft Windows software for the Winfast DVT Dongle is unable to tune the frequency of VK3RTV. DO NOT try to use this adaptor with the supplied software.

Leadtek Winfast DTV Dongle Gold USB TV Tuner

I connected a RG-6 coaxial cable from my antenna splitter to the Winfast DVT Dongle.

Using Ubuntu the Winfast DVT tuner is successfully able to lock on to VK3RTV1 and VK3RTV2.

I wrote a simple bash shell script to monitor VK3RTV. It checks once every 10 seconds for the repeater going on or off. As my computer has two DVB-T dongles installed I specified adaptor 1 ("-a 1").

The script is written to work with the current 2 channel configuration ("2 services"). It will also work when a signal is detected but without enough strength to find the 2 channels ("filter timeout pid").

#!/bin/sh

#
# Wait 30 seconds in case of reboot
#
sleep 30

TIMENOW=`date +%T`
MSG="$TIMENOW ATV producer restarted!"
HOSTNAME="Zentyal"

# VK3RTV = 0 (down)
# VK3RTV = 4 (up)
VK3RTV=`scan -a 1 /usr/local/bin/vk3rtv.conf 2>&1  | egrep 'filter timeout pid|2 services' | wc -l`

/usr/local/sbin/tick elvin://192.168.1.1 Status $HOSTNAME "$MSG" > /dev/null

#
# Initialise
#

#
# Loop for ever
#

while :
do

# Check if VK3RTV is UP or DOWN
   if [ `scan -a 1 /usr/local/bin/vk3rtv.conf 2>&1 | egrep 'filter timeout pid|2 services' | wc -l` -eq 0 ]
   then
    if [ $VK3RTV -gt 0 ]
     then
#      echo "VK3RTV has gone down..."
       TIMENOW=`date +%T`
       MSG="$TIMENOW VK3RTV is off air"
       /usr/local/sbin/tick elvin://192.168.1.1 Status $HOSTNAME "$MSG" 10 > /dev/null
       VK3RTV=0
    fi
   else
    if [ $VK3RTV -eq 0 ]
    then
#      echo "VK3RTV has come up..."
       TIMENOW=`date +%T`
       MSG="$TIMENOW VK3RTV is on air"
       /usr/local/sbin/tick elvin://192.168.1.1 Status $HOSTNAME "$MSG" 10 > /dev/null
       VK3RTV=4
    fi
   fi

# rest for a 10 seconds
   sleep 10

done

VK3RTV Checker Shell Script

TIP: I use adaptor 1 ("-a 1") as I have two adaptors installed. Otherwise you may omit the adaptor option to use the default adaptor 0.

The above script calls scan and passes it the following /usr/local/bin/vk3rtv.conf file.

vk3rtv.conf

The script calls my Elvin producer named tick. Details of my /usr/local/sbin/tick command line program may be found on my Elvin page:
http://www.rocode.com/elvin/#TICK.
The tick program generates an Elvin notification that is feed through my installation of the AVIS Event Router
http://avis.sourceforge.net/.

I start the bash script on boot in /etc/rc.local. When it detects a change with VK3RTV it will produce an Elvin notification that is displayed on any tickertape that is subscribed across my Local Area Network (LAN).

AVIS Routing

Here is a photo of my AVIS router with the second DVB dongle visible on top of the ASUS EeeBox PC. A RG6 coax cable from the antenna spliter is connected using two right angle adaptors.

AVIS PC Photo

The DVB dongle does not need to be inserted to the same PC as the AVIS Router. It is done here for convenience. The Elvin producer tick could be used to send the notification, from the PC with the DVB dongle, across the LAN to the AVIS Router.

The following screenshot shows how a VK3RTV checker notification looks on a subscribed tickertape running on my Windows 7 Desktop.

Sticker Tickertape and VK3RTV

The following screencast shows a real notification when VK3WWW started to use VK3RTV1 on 25th January 2012 at 7:40pm for the weekly WIA News broadcast. The screencast includes a web browser placed on the VK3RTV homepage to show, via live streaming, the ATV repeater coming on air.

VK3RTV and Tickertape

The following screenshot shows a history of notifications as stored in sticker running on my Windows 7 Desktop. This history is from Wednesday 18th January 2012 and shows the weekly WIA News broadcast at 8:00pm.

Sticker Messages and VK3RTV

Repair of Mac TV Dongle.

My housemate's EyeTV DTT TV Tuner Stick on his Mac broke. The USB Connector on the dongle detached from the PCB.

The retail cost for the USB dongle is $125. As a result we ordered a replacement USB 4 Pin 4P Male Panel PCB Connector Plug SMT pack of 3 on ebay for $2.

Ebay Advertisement

Using my Weller SP25D soldering iron I inserted the new USB Connector as shown in the photo below.

I had to remove the broken pins ends that were still inserted in to the PCB. I then soldered the 6 pins on the new USB Connector to the PCB. There are 4 signal pins and 2 mounting pins.

Mac TV Dongle Repair

The TV Dongle is now in working order again and can receive VK3RTV using the EyeTV software package running within OS X.

VK3RTV1 on a Mac using EyeTV

Watching VK3RTV1 and VK3RTV2 using a DGTEC set top box.

I use a DGTEC DG-FV7200 to watch the local ATV repeater. I enter 446500 khz manually and VK3RTV1 and VK3RTV2 may then be found on logical channels 350 and 351 respectively.

I connected a RG-6 coaxial cable from my antenna splitter to the DGTEC.

Here are some snapshots taken of my DGTEC with VK3RTV1 and VK3RTV2.

DGTEC and VK3RTV1	DGTEC and VK3RTV2
DGTEC Signal Report	DGTEC Channel List

These snapshots of my DGTEC with VK3RTV1 and VK3RTV2 were captured using a Pinnacle Instant DVD Recorder.

May Raspberry Pi be used with VK3RTV.

During 2012 the new educational and experimentation Linux credit card sized computer called Raspberry Pi ( http://www.raspberrypi.org/ ) was made available internationally for purchase.

The Raspberry Pi Model B

The Raspberry Pi Model B has built in Fast Ethernet, Two USB 2.0 ports and retails for �21.60 plus �4.95 shipping.

A number of Linux distributions are available for download ( http://www.raspberrypi.org/downloads ) and are usable with Raspberry Pi.

I am keen to try my existing USB DVB-T dongles with the Pi. Will the dongle work with a Pi Linux distribution?

Example TV Tuner

I am interested in using Raspberry Pi with VK3RTV in a numbers of ways:

Reception of VK3RTV1 and VK3RTV2 television.

The video application XBMC is working on the Raspberry Pi ( http://wiki.xbmc.org/index.php?title=Raspberry_Pi ). I wish to tune VK3RTV1 and VK3RTV2 using a USB DVB-T dongle in XBMC. The Raspberry Pi comes with a built in HDMI output and an audio jack for connecting a monitor and speakers.

Generating Elvin notifications about VK3RTV's operational status.

I would like to install the Elvin client library on to the Raspberry Pi and use the C library to monitor VK3RTV via a USB DVB-T dongle. An Elvin notification would be emitted when VK3RTV comes on air or goes off air.

Streaming of VK3RTV1 and VK3RTV2.

It would be interesting to use 2 Raspberry Pi's to tune and separately stream both VK3RTV1 and VK3RTV2 simultaneously over a local area network (LAN) using separate ethernet addresses.

I await to buy a Pi for myself and start experimenting with it.

Maintained by: Rohan Fletcher
Last update April 22 2012.