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DATV 1280MHz Input
Posted: Wed Mar 19, 2008 9:28 pm
by G1LPS Terry
Today GB3KM Got the go ahead for 1280MHz digital input.
This will be at 1024Ks/s and FEC of 1/2. initially to allow experiments with the poor mans atv tx system. But will be changed on request.
see M0DTS.CO.UK for more details of this cheap homebrew digital TX system.
Regards
Terry G1LPS
Re: DATV 1280MHz Input
Posted: Wed Mar 26, 2008 10:27 pm
by G1LPS Terry
Tonight we connected up the digital RX on 1280mhz.
The new reciver is a COMAG SL25 this receiver locks very quickly.
There's also a software option for the channel you want to power up on, a must for a repeater.
Within seconds of switch on Robert M0DTS was accesing with 90% qlty and 90% signal using his home brew DATV equipment.
- Modulator
- 23%20+13cm%20modulator.jpg (35.16 KiB) Viewed 15265 times
- Filter
- Buffer%20+%20Nyquist%20Filter.jpg (39.13 KiB) Viewed 15264 times
- Serializer
- Serializer.jpg (31.53 KiB) Viewed 15262 times
WELL Done Rob !!!
The COMAG SL25 model performed much better than the SL65 model tested by M0DTS. The lock of the SL25 only took about 1 second and could display a picture down to low signal levels. We'll keep you all posted about further findings on this recevier. The 1000 ks/s that this rx is capable of opossed to the usual 2000 ks/s is important for the exeriments being carried out using the "poor mans DATV System" which uses a pc parrallel port for the data stream (1024 ks/s). see M0DTS.CO.UK for more info.
Re: DATV 1280MHz Input
Posted: Fri Mar 28, 2008 10:42 pm
by M0DTS
WELL Done Rob !!!
The COMAG SL25 model performed much better than the SL65 model tested by M0DTS. The lock of the SL25 only took about 1 second and could display a picture down to low signal levels. We'll keep you all posted about further findings on this recevier. The 1000 ks/s that this rx is capable of opossed to the usual 2000 ks/s is important for the exeriments being carried out using the "poor mans DATV System" which uses a pc parrallel port for the data stream (1024 ks/s). see M0DTS.CO.UK for more info.
Thanks for putting the info up Terry, I forgot...!
Was nice to see my signal pop up so quickly with that receiver, and even with only a few watts!
See my website soon for info about my software to control the programs required to make the DATV stream files. This makes the 'Poor Man's Digital ATV Transmitter' into near_live video with ~1min delay.
Look out for more digital transmissions soon..
Rob
http://www.m0dts.co.uk/datv.htm
Re: DATV 1280MHz Input
Posted: Mon Jun 13, 2011 11:16 pm
by G1LPS Terry
The 1280mhz digital input is now set at symbol rate of 4000.
Re: DATV 1280MHz Input
Posted: Sat Dec 17, 2011 8:56 pm
by M0DTS
The Second station to access GB3KM on digital was seen over the last two days.
Brian, G3KJX at Northallerton was a fully locked signal at 38km from the repeater using 10W to a 15dB panel antenna, usual signals were P4 analogue with quite noisy sound.
Hopefully one more to come very soon... Down to you now barry G4ZCN....hi
G4FVP wil be following in Digital in the new year sometime.
73
Rob
M0DTS