449 UK simple irritating noise?

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Re: 449 UK simple irritating noise?

Post by JohnB57 »

26mb04 wrote: 02 Dec 2019, 17:56 ...one of the drawbacks with DMR over dPMR is that DMR users MUST be synchronised with each other and the repeater (if used) or the whole thing falls apart.
Pure DMR simplex doesn't require synchronisation as the timeslots are ignored. Dual Capacity Direct Mode and repeaters do, of course, require a timing sync signal from either a nominated timing leader or repeater. In both cases, lack of sync doesn't actually make things "fall apart", it's just impossible to gain access and you get the low beep of failure.
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Re: 449 UK simple irritating noise?

Post by 26mb04 »

Thanks for that! I wondered how it all worked, I knew there was something to with timing but not sure what as I'm still new to it myself.
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Re: 449 UK simple irritating noise?

Post by warlock01 »

hi andy,(i think that you was the you that posted the original post) i have read all off the posts , and although i don't quite know what type of noise you are refering to , there is a company called lh agro which transmit data on lots of freqencies including 449.450 and they have something to do with farm machinery tractor data ect and can wipe out some of the 449 mhz chanells the other one is 453.550 , which is a common railtrack frequency. if you look on the ofcom website you will find out which other frequencies are affected . i have one of these transmitters about 10 miles from me and it some of the 449.mhz chanells are unuseable
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