--- In [email protected], MCH <[EMAIL PROTECTED]> wrote:
>
> Another point: The only scanners that support the new SNFM channels
are
> those that also support trunking. Most scanners support trunking
these
> days. You can get a scanner that supports SNFM and trunking for a
couple
> hundred dollars. P25 scanners cost much more.
>
> Joe M.
>
> > Paul Plack wrote:
> >
> > Dick,
> >
> > I think you missed his point. If the scanner's microprocessor
leaves
> > you tuned several Khz off-channel, making the receiver more narrow
> > would actually make the problem worse.
> >
> > 73,
> > Paul, AE4KR
No, I didn't miss the point, it's just that others were
covering getting the microprocessor tunning on channel center, so
there was no point to my adding to that "pile"!!
So, I commented on narrowing the receiver responce accordingly so
as to eliminate the noise, etc., that would result from a narrow band
signal in a wide band radio...
First fix the channel centering, then narrowing the responce
accordingly.. one follows the other..
Dick
Dick
> >
> >
> > ----- Original Message -----
> > From: ocwarren2000
> > To: [email protected]
> > Sent: Monday, February 18, 2008 1:43 AM
> > Subject: [Repeater-Builder] Re: Wide Band / Narrow Band
> >
> > --- In [email protected], "Jim Cicirello"
> > <ka2ajh@>
> > wrote:
> > >
> > > We are going through the same growing pains here in Rural
> > Western
> > New York.
> > > The problems with the NON-TRUNKING SCANNERS, is they will
> > not go
> > out to 12.5
> > > KHz or even lower of a split. Here is an example; one of
> > our
> > frequencies,
> > > 155.0475. Now if you try to put that in your BC-895XLT it
> > will
> > round off.
> > > Another problem is that on the narrow band frequencies,
> > they use a
> > deviation
> > > of about 3 KHz. The scanners, even the new TRUNKING
> > SCANNERS that
> > will go
> > > out to the new narrow band frequencies will NOT
> > consistently decode
> > the
> > > lower generated PL Tones below about 4 KHz. I called
> > Uniden and
> > told them
> > > that I wanted a list of scanners that would do the new
> > narrow band
> > > frequencies BUT DID NOT NEED TRUNKING. He told me that the
> > only
> > scanners
> > > they have capable of narrow band are the TRUNKING UNITS.
> > Now if you
> > are
> > > close to the transmitter, you can sometimes hear the
> > rounded off
> > frequency
> > > OK without distortion. And if the PL don't decode, use
> > carrier
> > squelch.
> > > Hopes this helps. Join the crowd of the new Narrow Band
> > Generation.
> > >
> > >
> > >
> > > _____
> > >
> > > From: [email protected]
> > > [mailto:[EMAIL PROTECTED] On Behalf Of
> > rrath@
> > > Sent: Sunday, February 17, 2008 12:09 PM
> > > To: [email protected]
> > > Subject: [Repeater-Builder] Wide Band / Narrow Band
> > >
> > >
> > >
> > > Our local fire, police and ambulance departments are going
> > to
> > Narrow Band
> > > per the FCC. I was told by one fire department that their
> > pagers
> > will only
> > > work one narrow band. Now this guy must be talking about
> > the tones
> > for the
> > > pagers? But to me wide or narrow the tones are the same.
> > Right?
> > Going
> > > narrow just means that they are taking up less of the band
> > width
> > for their
> > > frequency? He also said that scanners will not be able to
> > listen to
> > them
> > > unless the scanner is set up for narrow band. His wife
> > gave me her
> > nice
> > > Uniden BC-895XLT scanner because her husband told her the
> > same
> > thing.
> > > Some one who is in the know would like to fill us in on
> > the topic.
> > All EMS
> > > departments will be narrow band by April, in our area;
> > from what he
> > said.
> > >
> > > Rod
> > >
> >
> > Well, guys, it's not all that hard to narrow band a wide
> > band receiver, by narrowing the IF frequency amplifier /
> > limiter
> > circuit string by decreasing the coupling between stages and
> > making a
> > responce curve that looks like an inverted "V" rather than a
> > modified
> > inverted "W"..!! Modifying the discriminator depends on what
> > kind of
> > circuit it uses.
> >
> > Years ago when everybody went down to + - 5kc from + - 25KC,
> > that's
> > what we did.. On transmit just turn down the modulation..
> > best done
> > with a Deviation Meter or a Service Monitor..
> >
> > Dick, CET, W7TIO
> >
> >
>
