[Scan-DC] Re:Lot'a Skip Or Is That "tropospheric ducting"

[john wilson]

   E layer refraction typically involve low band vhf transmissions with a single
hop of 1,000-1,500 miles and double hops 2,500-3,000 miles.
The ionization is very unstable in forming and disappating.  Ducting typically
involves non-refracted signals that are received
beyond their normal ground wave range due to cold/warm layer atomospheric
relationships that tend have the effect of having the radiated signals
temporarilty be received farther than normal.  Signals with rare exceptions above
100 mhz. involve ducting.

al wrote:

>   Good info.
>
> I entered the FD freq to see if they come in like the others.
>
>   One thing I've noticed about this subject is that when they don't come
> in  anymore it's not a fade-out situation where the trans start's to break
> up & then you hear nothing.It's like one minute great sig then the next
> nothing.
>
>   Al
>
> >Al & All...
> >
> >   You are picking up Jefferson County, WVA.  The units with the 'large'
> >numbers are Harpers Ferry/Bolivar PD, Charlestown/Ranson PD, and
> >Shepardstown/Shepard College PD.  Smaller numbered units are Jefferson
> >County Sheriff and WVSP.  As you can see, every Law Enforcement agency in
> >Jefferson County works off one net.  You can probably pick up Jefferson
> >County fire on 153.860 as well.
> >
> >Jason Grabill
> >Brunswick, Frederick County Md
> >----- Original Message -----
> >From: "al" <ald61650 at comcast.net>
> >To: <scan-dc at mailman.qth.net>
> >Sent: Friday, July 02, 2004 9:37 AM
> >Subject: [Scan-DC] Lot'a Skip Or Is That "tropospheric ducting"
> >
> >
> > >
> > > >Been getting alot of skip on the Charles county (md) pd freq',154.875,
> > > >this AM.
> > >
> > >   These guy's,assumed a WV PD,are coming in as good as the local pd's this
> > > morn (7-2-04).
> > >
> > >   When a street unit calls hq he say's "42104 to headquarters" or "104 to
> > > headquarters".
> > >
> > > But then I heard another officer say "50 to county" & the dispatcher
> > > answered him.
> > > I'm pretty sure there was two different sounding dispatchers but there was
> > > a lot'a time in between trans.
> > >
> > >   The only thing I AM sure of is that the trans are not the local pd here.
> > >
> > >   Al
> > > --
> > > al dudley ....wash dc metro , usa
> > >      ald61650 at comcast.net
> > >             *************
> > >     pro 2006,2052,pcr1000,r100
> > >
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>
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