NBTV 160 Meter Test, 1855 kHz, 6 June 2009, Melbourne, Australia, by VK3ASE and VK3AML. скачать в хорошем качестве

NBTV 160 Meter Test, 1855 kHz, 6 June 2009, Melbourne, Australia, by VK3ASE and VK3AML.

32 lines @ 12.5 pictures/second - transmitted by VK3ASE, received by VK3AML over a 15 km range, using a stock standard 100 watt a.m. transmitter and a transistor radio broadcast receiver. The setup was not optimised in any way, but was run purely to see what would happen to pictures using an unmodified audio channel for the video. It was transmitted near midnight on Saturday, 6 June 2009, on 1855 kHz, on the 160 meter amateur band. We honestly didn't think that the rude finger gesture would be recognisable - ugh - oh well, my bad! There are obvious phase shifts, overshoot and noise in this - the transistor radio receiver used an internal ferrite rod antenna, and the levels recorded were well below optimum. For a first effort on an unmodified link on 1855 kHz, not too bad. The receiver's AGC is rather too fast to permit the low frequency response necessary for NBTV (ideally 10 Hz - 6 kHz). On our next test, a receiver with a broad, phase-flat I.F. will be used, and an external antenna should produce better signal-to-noise. There is a HUGE amount of room for improvement, obviously. Nevertheless, this proves that viable moving picture television can be transmitted on the lower h.f. ham bands with simple equipment. My thanks to VK3ASE for providing transmitting facilities. Video software (32-line NBTVA standard) was designed and provided by Gary Millard of Sydney, refer: http://users.tpg.com.au/users/gmillar... Those interested in television transmitted in a narrow bandwidth should also refer: http://www.nbtv.wyenet.co.uk/