Malta Amateur Radio LeagueMalta Amateur Radio League

Compiled and Presented by Compiled and Presented by

Stanley Grixti – 9H1LOStanley Grixti – 9H1LO

What exactly is ATV?What exactly is ATV?

Amateur TelevisionAmateur Television is the transmission is the transmission of either of either Slow Scan Slow Scan pictures (SSTV) or pictures (SSTV) or Fast ScanFast Scan pictures (FSTV). pictures (FSTV).

ScanScan meaning the “ meaning the “drawingdrawing” of the ” of the picture on the screen.picture on the screen.

SSTVSSTVSlow ScanSlow Scan is normally used on the narrow bandwidths of is normally used on the narrow bandwidths of HFHF and and VHFVHF..Usually Usually SSBSSB and and FMFM. . The The pictures are converted into audiopictures are converted into audio and sent and sent one at a timeone at a time..Each Each frameframe takes about takes about 3 mins3 mins to be sent! to be sent!VeryVery noisy noisy and and unreliableunreliable..Nowadays sent / received using a PCNowadays sent / received using a PCMIR Space Station used to Transmit SSTV!MIR Space Station used to Transmit SSTV!

FSTVFSTV FSTVFSTV is generally termed is generally termed ATVATV..25 frames per second25 frames per second can be sent (Live Video). can be sent (Live Video).AudioAudio channels can be used as channels can be used as sub-carrierssub-carriers..Same as broadcast TV standard (PAL B).Same as broadcast TV standard (PAL B).Mode is Mode is Wide Band FMWide Band FM..Used on Used on MicrowaveMicrowave bands: bands:

1.2GHz , 2.4GHz , 5.7GHz , 10GHz , 24GHz1.2GHz , 2.4GHz , 5.7GHz , 10GHz , 24GHzNormally AnalogNormally Analog but Digital (DVB-S) but Digital (DVB-S)

transmitters are available.transmitters are available.

Who uses ? & Why ATV ?Who uses ? & Why ATV ? ATV is one of the for-fronts in amateur radio ATV is one of the for-fronts in amateur radio technology.technology.

It is used in contests, DX-Peditions, Ham-Fairs It is used in contests, DX-Peditions, Ham-Fairs ectect

There is an fortnightly ATV “magazine” There is an fortnightly ATV “magazine” transmitted from Sweden via the commercial transmitted from Sweden via the commercial broadcast satellite Sirius. This is receivable with a broadcast satellite Sirius. This is receivable with a digital satellite TV System. Just turn the dish to the digital satellite TV System. Just turn the dish to the Sirius satellite and set the right frequency!!Sirius satellite and set the right frequency!!

Who uses ? & Why ATV ?Who uses ? & Why ATV ? With the help of 9H1ATV local field days and other With the help of 9H1ATV local field days and other events can be broadcast live, also construction projects events can be broadcast live, also construction projects and lectures can be given “on the air”and lectures can be given “on the air”

Unfortunately an amateur satellite with an ATV Unfortunately an amateur satellite with an ATV repeater payload is not yet in orbit, however there are repeater payload is not yet in orbit, however there are plans of having one as Phase 4 (Geo-stationary).plans of having one as Phase 4 (Geo-stationary).

Many Sicilians are active on ATV which will surely Many Sicilians are active on ATV which will surely be of advantage to local 9H stations!be of advantage to local 9H stations!

9H1LO – JM75EW

IT9TWC - IT9TWC - IT9TWC - IT9

ATV via Ragusa ATV ATV via Ragusa ATV repeaterrepeater

ATV ATV TransmittersTransmitters / Receivers / Receivers

Can be built.Can be built.Can be Can be purchased from G1MFGpurchased from G1MFG (1.2GHz 65mW (1.2GHz 65mW

Transmitter about Lm30.00)Transmitter about Lm30.00)TVRO TVRO LNBs can be modifiedLNBs can be modified into 100mW 10GHz into 100mW 10GHz

transmitters.transmitters.Normal antennasNormal antennas for the given band can be used for the given band can be used

however consideration must be taken for higher however consideration must be taken for higher bandwidthsbandwidths

Yagi, Dipole, Dish, HornYagi, Dipole, Dish, Horn, or any suitable antenna., or any suitable antenna.

ATV TransmittersATV Transmitters

Homebrew 10GHz ATV Homebrew 10GHz ATV Transmitter with Transmitter with Audio/Video modulator. Audio/Video modulator. 65mW Output.65mW Output.

1.2GHz ATV Transmitter 1.2GHz ATV Transmitter from G1MFG.from G1MFG.

ReceiversReceiversAmateur receiversAmateur receivers available for 1.2GHz and available for 1.2GHz and

2.4GHz from G1MFG.2.4GHz from G1MFG.Surplus Surplus domestic analogue TVROdomestic analogue TVRO Receivers can be Receivers can be

used for 1.2GHz and also 10GHz using a normal used for 1.2GHz and also 10GHz using a normal LNB.LNB.

For 1.2GHz a For 1.2GHz a pre-amplifierpre-amplifier might be needed. might be needed.

The same as in the transmitter applies for antennas.The same as in the transmitter applies for antennas.

Reception at 10GHz would normally be anReception at 10GHz would normally be an LNB LNB mounted on a small mounted on a small Dish Dish or a or a HornHorn..

ReceiversReceivers

1.2GHz Receivers from G1MFG. They can also be used for 10GHz with A cheap satellite TV LNB.

Receive setup using a domestic receiver. (set-top box)Receive setup using a domestic receiver. (set-top box)

Other EquipmentOther EquipmentVideo CameraVideo CameraComputer with video outComputer with video outTest Card GeneratorTest Card GeneratorPAL TV / MonitorPAL TV / Monitor

9H1ATV9H1ATVA microwave amateur television repeater

The Idea Behind 9H1ATVThe Idea Behind 9H1ATVThe idea of having a local ATV repeater is to encourage and The idea of having a local ATV repeater is to encourage and

educate interested amateurs to equip themselves to operate this educate interested amateurs to equip themselves to operate this mode.mode.

It will also help to increase the distance of contacts, and will It will also help to increase the distance of contacts, and will also serve as the mid-med ATV hub, when eventually it will be also serve as the mid-med ATV hub, when eventually it will be linked to the ever expanding ATV repeater network in Sicily.linked to the ever expanding ATV repeater network in Sicily.

It will provide easy setup access, I.E. stations will only need a It will provide easy setup access, I.E. stations will only need a minimum amount of equipment and power to access the minimum amount of equipment and power to access the repeater.repeater.

It will provide interesting contacts especially from /M & /P It will provide interesting contacts especially from /M & /P stations!!stations!!

The RepeaterThe Repeater

1.2 GHz Receiver1.2 GHz Receiver

TX & ControllerTX & Controller

1.2GHz Antenna1.2GHz Antenna

Audio

Audio

Video

Video

10GHz Slotted Waveguide

10GHz Slotted Waveguide

9H1ATV - Facts9H1ATV - Facts 9H1ATV was designed and built by 9H1LO9H1ATV was designed and built by 9H1LO

The 1.2 GHz receive antennas was built by 9H1ESThe 1.2 GHz receive antennas was built by 9H1ES

The 10GHz transmit antenna was built by 9H1PFThe 10GHz transmit antenna was built by 9H1PF

It was installed in Mdina in March 2004 by 9H1LO & 9H1ESIt was installed in Mdina in March 2004 by 9H1LO & 9H1ES

9H1ATV - Facts9H1ATV - Facts Funding was from MARL, 9H1LO and 9H1ESFunding was from MARL, 9H1LO and 9H1ES

It transmits a test card when no signal is receivedIt transmits a test card when no signal is received

Output frequency is 10.475GHzOutput frequency is 10.475GHz

Input frequency is 1255MHzInput frequency is 1255MHz

It will switch to the received signal upon detecting It will switch to the received signal upon detecting VIDEO and not just a carrierVIDEO and not just a carrier

If video ceases it will return to the test card after If video ceases it will return to the test card after 8seconds8seconds

9H1ATV 1.2 GHz Receive antenna9H1ATV 1.2 GHz Receive antenna

Transmit & Receive AntennasTransmit & Receive Antennas

9H1LO & 9H1ES9H1LO & 9H1ESJust after switching 9H1ATV on the AirJust after switching 9H1ATV on the Air

9H1ES installing the 9H1ATV antennas at Mdina9H1ES installing the 9H1ATV antennas at Mdina

Receiving 9H1ATVReceiving 9H1ATV Stations will need to have the ability to receive Stations will need to have the ability to receive

an analog video/audio signal at 10.475GHzan analog video/audio signal at 10.475GHz

This is done with an analog satellite receiver This is done with an analog satellite receiver and a modified LNBand a modified LNB

Antenna should be a horn or preferably a dishAntenna should be a horn or preferably a dish

The 9H1ATV test cardThe 9H1ATV test card

Analog Satellite ReceiversAnalog Satellite Receivers These are the old type of TVRO receiversThese are the old type of TVRO receivers

Frequency range is normally 900MHz – 2000MHzFrequency range is normally 900MHz – 2000MHz

They are to be used as an IF with an LNB They are to be used as an IF with an LNB

They normally have a SCART or Phono output that They normally have a SCART or Phono output that connects to your TV or monitorconnects to your TV or monitor

PC Card tuners can be used but not advisable as they PC Card tuners can be used but not advisable as they are slow when it comes to synchronizingare slow when it comes to synchronizing

CRT monitors or TV’s are better than TFT monitors as CRT monitors or TV’s are better than TFT monitors as TFT’s are slow at synchronizingTFT’s are slow at synchronizing and difficult to find a and difficult to find a weak signalweak signal

ReceiverReceiver

Coverage is 900MHz – 2000MHz so an LNB (down converter) Coverage is 900MHz – 2000MHz so an LNB (down converter) must to used to convert 10GHz to about 1GHzmust to used to convert 10GHz to about 1GHz

LNB (Low Noise Block)LNB (Low Noise Block)The LNB is a down converter from about The LNB is a down converter from about

10.7GHz - 12GHz to 900MHz – 2GHz10.7GHz - 12GHz to 900MHz – 2GHz

They have a built in horn and transition that They have a built in horn and transition that is mounted on the dish to receive the signal is mounted on the dish to receive the signal from the satellitefrom the satellite

They have 2 Local Oscillators: 9.75GHz and They have 2 Local Oscillators: 9.75GHz and 10.6GHz10.6GHz

Mathematics!Mathematics!To receive 10.475GHz the LNB’s 9.75GHz LO To receive 10.475GHz the LNB’s 9.75GHz LO

has to be tuned to 9.4GHz as: has to be tuned to 9.4GHz as:

10.475GHz – 9.75GHz = 725MHz10.475GHz – 9.75GHz = 725MHz

725MHz is below the range of the receiver725MHz is below the range of the receiverSo if the LO is changed to 9.4GHz then:So if the LO is changed to 9.4GHz then:

10.475GHz – 9.4GHz = 1.075GHz10.475GHz – 9.4GHz = 1.075GHz

The Oscillator in the LNBThe Oscillator in the LNB The LO is simply a DRO (dielectric resonant oscillator) The LO is simply a DRO (dielectric resonant oscillator)

which works similarly to a normal crystal oscillator but at which works similarly to a normal crystal oscillator but at GHZ frequencies!GHZ frequencies!

It can be tuned down 350MHz by raising it 1mm above the It can be tuned down 350MHz by raising it 1mm above the PCB with some super glue and re-tuning with the tuning PCB with some super glue and re-tuning with the tuning screw.screw.

It can be aligned on a satellite signal…such as RAI 1 on the It can be aligned on a satellite signal…such as RAI 1 on the Hotbird Satellite…simple re-tune the DRO until you find Hotbird Satellite…simple re-tune the DRO until you find RAI 1 350MHz below it’s original frequency!RAI 1 350MHz below it’s original frequency!

An normal TVRO LNBAn normal TVRO LNB

The DRO tuning screwsThe DRO tuning screws

AntennasAntennas

GasFet pre-ampsGasFet pre-amps BP FilterBP Filter

MIXERMIXER

DRODRO

Logic / SwitchingLogic / SwitchingPowerPower IF OUTIF OUT

Anatomy of an LNBAnatomy of an LNB

The DRO “Puck” The DRO “Puck”

(Puck removed to show components)

(Puck removed to show components)

9.75GHz 10.6GHz9.75GHz 10.6GHz

DRO “Pucks”DRO “Pucks”

Receiving 9H1ATVReceiving 9H1ATV Once the DRO is tuned to 9.4GHZ you should Once the DRO is tuned to 9.4GHZ you should

be able to receive from 10.3GHz to about be able to receive from 10.3GHz to about 11.7GHz11.7GHz

Once the LNB is mounted on the dish and Once the LNB is mounted on the dish and pointed at Mdina you should receive 9H1ATV pointed at Mdina you should receive 9H1ATV on 10.475GHz on 10.475GHz

The IF should be 1.075GHzThe IF should be 1.075GHz 10.475GHz – 9.4GHz = 1.075GHz 10.475GHz – 9.4GHz = 1.075GHz

Receiving 9H1ATV RepeaterReceiving 9H1ATV Repeater