Getting started in Amateur Television. BATC - August 2016

Transcription

1 Getting started in Amateur Television BATC - August 2016

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 GB3SQ net night on Sunday at 8pm Bournemouth ATV group 35+ viewers

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 And there s probably a repeater near to you!

15 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 Still available from Roy G8CKN Use existing pre-amp and PA And access local repeaters or work simplex But what about digital?

16 Receiving 23cms ATV Pre-amp FM rxr Satellite line amp Digital rxr

17 How to receive the 3.4 GHz 3.4 GHz is EASY! Free to air satellite box Not Sky Maplin 30 C band LNB from ebay Titanium satellite 25 Sky dish or M&S horn!! G0EHV at 20 Kms

18 3.4 GHz receive system C band LNB

19 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 Parts still available from G8AJN BATC DTX1 Complete encoder, modulator & upconverter Covers 150MHz to 2GHz Available from the BATC shop DATVExpress Very flexible hardware and Win s/w RB-TV and DATV 65 MHz 2.4 GHz

20 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

21 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 -tv/ or BATC forum

22 USB tuner project Specifically designed for DATV Wide and narrow band Easy hardware project Parts available from BATC shop Free software from F5DZP Advanced receiver And diagnostic tools

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 forum and wiki Supports projects such as USB tuner Represents ATV community on ETCC Runs BATC shop for hard to get bits Annual convention Only 6 for a cyber membership!

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