Thanks for your reply, however we have been using that SR for sometime now. It was set to that figure has we can have 3 x 6 MHz DATV channels within our 18 MHz FM band. Therefore according to the Excel chart for nearest 6Mhz bandwith and to provide the correct ratio SR/Fc, 4286 was the closest one. Some repeaters are using 5000 others 7500 so adjustment should be provided to make this happen. I am not sure what others so in Europe or USA are using?g4wvu wrote:Just seems an odd number - i.e. why not round up or down to the nearest hundred e.g 4.2MS or 4.3MS (or even just 4MS/s ) etc.vk4xrl-DATV wrote:4.268 MSym/s .......interesting / strange SR for a repeater input ?
Why so its a valid SR input?
The extra 68KS or 32 less, wouldn't make any practical difference to the effective video quality for DATV purposes. Many coders / modulators will only cater for a fixed spread of rates, often at multiples with 0s e.g. 2000, 3000, 4000 etc.
http://www.spectra-bv.nl/dvb_modulator_lband.html . DTX1 also is adjustable to the nearest 100KS/s (at the moment - I hasten to add - sounds from one of the replies like a FW edit. might be in the pipeline!)
Thank you, Richard VK4XRL