--- In Repeater-Builder@yahoogroups.com, "nj902" <wb0...@...> wrote: > > If you are referring to the 2.5 KHz steps - that's necessary so the radio can > be programmed on whatever frequency is necessary due to the variety of band > plans and channel spacings. That doesn't mean that in any one geography > there is any intent to have adjacent channel operations 2.5KHz apart. > > --------------------------------------------------------- > > --- In Repeater-Builder@yahoogroups.com, "afa5tp" <w7trh@> wrote: > > > > Hello Group, > > > > I may be confused....so please set me straight. > > > > I thought that the new "Narrow Band" was the narrowing the channel spacing > > from 25kHz. to 12.5kHz, and of course, knocking down the deviation from 5 > > kHz. to 2.5 kHz. > > > > On the subject of affordable "Narrow Band" gear....I highly recommend the > > Icom F-121 (VHF), or F-221 (UHF). These radios feature PC programming, and > > are wide/narrow band selectable per channel. Price is about $275.00 for the > > eight channel version. There is a 128 ch. version available for more $$$$! > > > > I guess I am "Waiting in the Wings", like everyone else.....! > > > > TIM W7TRH/AFA0TP Wa. > > > > > > > > --- In Repeater-Builder@yahoogroups.com, wd8chl <wd8chl@> wrote: > > > > > > James Delancy wrote: > > > > > > > > Glad to see my posts are making it. In the commercial and public > > > > safety world > > > > (Motorola style primarily as I am not entirely up on all the others > > > > except to > > > > find that the Kenwood, Icoms and Vertex stuff was slow to adopt 2.5 KHz > > > > steps), > > > > if it accepts 2.5 Khz steps, then you can select narrowband and it will > > > > narrow > > > > up its IF's for receive, boost the audio on RX and narrow down the > > > > transmit > > > > accordingly. All of the ham stuff that I have now will do narrowband, > > > > but most > > > > will NOT do a 2.5 KHz step. Does that help clarify it ;) > > > > > > > > James WJ1D > > > > > > Again, as of about 13 years ago or so, the FCC mandated that narrowband > > > modes be included in radios for Part 90. The 2.5 KHz steps issue is not > > > related at all. > > > > > >
Hi everybody... Don't check it now, but we already are at plus and minus 2.5 kc deviation!!! IF they do that to channel frequncy spsacing, AS LONG AS EVERYBODY IS THE SAME it will work.. When the Feds created National Telecommunications Industry Administration to be another FCC to govern other people, it created 2,500 KC Deviation in place of 3,500 to keep everything within limits, with a pl deviation of 250 cps in place of 300 cps! My wife bought a 2 meter radio in about 2001 and I checked it with my Service Monitor, after some discusssuion and it tested out at 250 deviation PL and 2,500 voice!! All the radios are that way now, and nobody has noticed it!!! The ham manufactures did that to keep the compatableity with NTIA specs and nobody has noticed!! As to 2,500 Khz channel seperation of operating frequencies, it has worked well as it did at 25 kc deviation frequencies, and still works at AS LONG AS EVERYBODY IS THE SAME!!! Some radios may haver to change I.F. filters, but that is in manufacturing... IF we were all Digital, I'm retired Western Union Tech that went to work in Mobile Rsadio Communications when W.U. went out of busibess. Frequeny shift multiplxed audio data could run well at 70 cps frequency shift, and at a negatinve 40 db, but voice is NOT that compatable, and voice had to run at 300 - 3500 cps, and for voice reconigation, higher levels as it was just noise at the same minus 40 db!!! The two are NOT compatable!!! Dick, W7TIO, CET
