Getting started in Amateur Television. Noel Matthews G8GTZ

Transcription

1 Getting started in Amateur Television Noel Matthews G8GTZ

2 Getting started in ATV What is ATV? Which band and where? Analogue or digital? BATC video portal How do I get on air? It s not all about radio! Who are the BATC? ATV why not!

3 What is Amateur Television? ATV is a niche area of amateur radio Includes video production, editing and transmission Covers classic camera restoration right through to transmitting live pictures using Raspberry PI from balloons! Real freedom to experiment ATV generally refers to fast scan TV

4 ATV - the bands 146 MHz! The new ATV band! 70cms Digital only on 437MHz Real potential for DX 23cms Analogue and digital Activity on repeaters and simplex 13cms Currently analogue and digital Repeaters and simplex 3.4 GHz The new band! Digital only 10 GHz Repeaters and simplex

5 Analogue Amateur TV Up to 10 years ago, everything was analogue Bands 70cms 8 MHz AM! 23cms 16 MHz FM 3cms 16 MHz FM And it still works well!

6 G to PA on 10 GHz at sea level!

7 The world is going digital But why digital TV? MPEG-2 SD compresses 270Mbit/s to 2Mbit/s MPEG-4 compresses HD at 1.3Gbit/s to 8 Mbit/s 99% reduction in bit rate but still better than VHS quality? watch the background and grass! Compressed video is much more efficient to transmit Freeview = 6 SD channels in place of 1 PAL signal in 8MHz! Hence the commercial pressure to go digital

8 ATV is going Digital The move to digital is happening Been experimenting for over 10 years Pressure on spectrum eg 13cms More modern image and new challenge Broadcast standards are being adopted DVB-S at 2 or 4 Msymbols 4 MHz vs 16 MHz Significant bandwidth gains and better pictures when it s there!

9 Analogue vs Digital ATV FM analogue 16 MHz deviation ~ 16 MHz DVB-S QPSK, 1.6 Msymbols, ½ FEC ~ 1.6 MHz

10 Analogue vs Digital ATV

11 So how do I get started? Go to The internet portal for all amateur television Most UK ATV repeaters are streamed live Watch your local repeater and join in with the discussion on the chat window

12 BATC.TV not just repeaters Bringing amateur radio to a wider audience Live events Club talks (NARC) National Hamfest GB70DAM HAB launches The archive Amateur radio s youtube EME 2012 AMSAT colloquim Microwave RT

13 BATC.TV - activity nights Up to 18 UK Amateur TV repeaters 16 international repeaters from Australia, USA, Ireland and Argentina. Night Repeater/Group Comments Time Sunday GB3SQ - Bournemouth G8AJN member stream 8pm Monday VK2RTS Sydney VK2CRJ member stream 11:00am GB3IV Isle of Wight Talkback on GB3IW 8pm Tuesday GB3TM 7pm GB3HV - Reading Live club meeting on 4 th Tuesday 8pm Wed VK7OTC DATV experimenters evening 10:30am GB3BH - Watford 8pm GB3ZZ - Bristol GBNQ - Cornwall 8pm 8pm Thursday GBPV - Cambridge 7pm GB3TB - Torbay 8pm GB3UT - Bath 8pm Friday GB3GG - Grimsby 8pm GB3EN - Enfield 8:30pm

14 ATV on the air - repeaters 30+ repeaters in the UK Most repeaters now have a DATV input 23cms & 70cms Some have switchable DATV output Some digital only GB3VL in Lincoln

15 GB3HV - Farnham 3.4 GHz digital output Also streamed on BATC.TV Is very easy to rx! 23cms & 70cms inputs Tuesday Activity night Watch batc.tv Call on

16 How to receive GB3HV 3.4 GHz is EASY! Free to air satellite box Not Sky Maplin 30 C band LNB from ebay Or BATC shop 20 Sky dish or M&S horn!! G0EHV at 20 Kms

17 GB3HV receive system C band LNB

18 23cms ATV rx Pre-amp FM rxr Satellite line amp Digital rxr

19 But how to get on air... 23cms ATV is the place to start If you have a reasonable narrow band station you are half way there! Buy a Comtech Tx and Rx module Use existing pre-amp and PA And access GB3HV G8FRC does! But what about digital?

20 DATV Tx equipment Ex broadcast equipment Works well but big, noisy and hot! BATC Digilite project Use PC and TV card to digitise video DIY project for modulator and upconverter BATC DTX1 Complete encoder, modulator & upconverter Covers 150MHz to 2GHz Available from the BATC shop

21 New ATV band at 146 MHz Ofcom have awarded the new MHz band for new technologies only Not more of the same FM etc watts erp maximum RSGB has allocated middle 500 Khz for DATV Experimenting with very narrow band DATV Reduced bandwidth or RB-TV Kbit/s MPEG-4 Existing equipment will not work

22 RB-TV on a Rpi Plug in QPSK modulator board developed by G4EWJ Software developed by F5OEO Uses Pi camera or recorded files Complete DATV transmit system on Rpi 500 KHz (Ofcom love it!) 70, 146 or 432 MHz Best dx so far is 160 Km on 70cms! More details see or BATC forum

23 But that's not all... ATVers are involved in video production Historic camera and vehicle restoration ISS HAM TV

24 The BATC 950+ members worldwide Publishes CQ-TV in e and paper format Runs highly successful streamer Active ATV community online forum Supports projects such as RpiDATV Represents ATV community on ETCC Runs BATC shop for hard to get bits Annual convention Only 6 for a cyber membership!

25 How to get started There is a repeater near you! GB3HV at Farnham Listen on ATV calling channel Buy a C band LNB Get a Sky mini dish from the tip! Rx GB3HV Talk to Peter and Tony

26 ATV get involved and do some real radio today! Thank you and don't forget to visit batc.tv