[ARC5] FCC General exam

Tue Nov 26 14:13:17 EST 2013

.....since renamed the light-dimmer/switching-power-supply band.

Dennis AE6C

On Tue, Nov 26, 2013 at 11:10 AM, Fuqua, Bill L <wlfuqu00 at uky.edu> wrote:

>   That would have been in the middle of the Loran-C band 90-110kHz.
> 73
> Bill wa4lav
>
> ________________________________________
> From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on
> behalf of D C _Mac_ Macdonald [k2gkk at hotmail.com]
> Sent: Tuesday, November 26, 2013 2:02 PM
> To: Bruce Long; KM1H Carl H.; ARC-5 Mail List
> Subject: Re: [ARC5] FCC General exam
>
> Theoretically a maybe, but practically speaking, how much signal will be
> heard amidst all the atmospheric noise at 100 kHz?  Well, I admit I don't
> have a RX to listen there.
>
>
> * * * * * * * * * * *
> * 73 - Mac, K2GKK/5 *
> * (Since 30 Nov 53) *
> * k2gkk hotmail com *
> * Oklahoma City, OK *
> * USAF & FAA (Ret.) *
> * * * * * * * * * * *
>
>
>
> > Date: Tue, 26 Nov 2013 10:51:02 -0800
> > From: coolbrucelong at yahoo.com
> > To: geoffrey at jeremy.mv.com; k2gkk at hotmail.com; arc5 at mailman.qth.net
> > Subject: Re: [ARC5] FCC General exam
> >
> > a long long time ago when I was a novice there was an uproar about a FCC
> propagation question.  The question was "What frequency is most reliable
> for long range communications?  Most hams would of course answer 14 MHz
> which is arguably the correct answer for the amateur service  but the
> "Correct" answer was 100 kHz because of ground wave propagation which is
> global in extent and largely unaffected by the state of the ionosphere.
> >
> >
> > On Monday, November 25, 2013 8:47 PM, Geoff <geoffrey at jeremy.mv.com>
> wrote:
> >
> > Yep, I still say sunset at least at one end of the path is the real
> answer
> > that most mainstream academics totally miss and gives the very long
> distance
> > grayline propagation which extends from MF to at least 10M.
> >
> > Low band DXers work anywhere on the planet at their sunset or sunrise (I
> > have close to 300 DXCC countries on 160 and a lot more on 80 and 40.
> > And it is rather amazing to have a dead 10M at a low spot of the sunspots
> > and have a short opening into the deep South Pacific at sunset where even
> > 10W can be loud.
> >
> > Carl
> >
> >
> >
> > ----- Original Message -----
> > From: D C _Mac_ Macdonald
> > To: Fuqua, Bill L ; KM1H Carl H. ; ARC-5 Mail List
> > Sent: Sunday, November 24, 2013 10:09 PM
> > Subject: RE: [ARC5] FCC General exam
> >
> >
> > I seem to remember having been taught in USAF electronics school (a LONG
> > time ago) that 160, 80, and 40 work so well at night because the D-layer
> is
> > activated by sunlight and absorbs those lower frequencies during the day.
> > This absorption goes away after sunset, allowing that energy to actually
> > REACH the F-layer to be refracted.
> > My SWAG would be that of Carl's; right around sunset.
>
> >
> > * * * * * * * * * * *
> > * 73 - Mac, K2GKK/5 *
> > * (Since 30 Nov 53) *
> > * k2gkk hotmail com *
> > * Oklahoma City, OK *
> > * USAF & FAA (Ret.) *
> > * * * * * * * * * * *
> >
> >
> >
> >
> >
> > > From: wlfuqu00 at uky.edu
> > > To: geoffrey at jeremy.mv.com; arc5 at mailman.qth.net
> > > Date: Mon, 25 Nov 2013 02:26:16 +0000
> > > Subject: Re: [ARC5] FCC General exam
> > >
> > > No, the F layer at night is the residual ionized atoms left after no
> Sun
> > > light is
> > > shining on it. That is why you get such good DX on 160 80 and 40 meters
> > > at night. Because the density of the atmosphere is low at higher
> altitudes
> > > the
> > > atoms and ions are further away reducing the chance of recombination.
> The
> > > electrons are what actually do the refraction. The interact with each
> > > other
> > > like balls with springs between them trying to push them apart. They
> are
> > > resonant.
> > > This is called the plasma resonant frequency. These act sort of like
> the
> > > parasitic
> > > reflector on a bean antenna. Very loose analogy but the simplest I can
> > > come up
> > > with just now.
> > > An atomic physicist and I sat down at lunch one day and talked about
> the
> > > plasma
> > > resonance formula and he said it was hard to derive because it is done
> in
> > > 3 dimensions
> > > I suggested trying to derive in in one-dimension and with a couple of
> > > napkins and felt
> > > point pen we came up with the same formula. This was a calculation of
> > > plasma resonance
> > > vs electron density.
> > >
> > > 73
> > > Bill wa4lav
> > >
> > >
> > > ________________________________________
> > > From: Geoff [geoffrey at jeremy.mv.com]
> > > Sent: Sunday, November 24, 2013 8:34 PM
> > > To: Fuqua, Bill L; ARC 5
> > > Subject: Re: [ARC5] FCC General exam
> > >
> > > And the E layer is highest just after sunset according to what I just
> > > read.
> > > Without sunspot activity there is no F layer after dark.
> > >
> > > Carl
> > >
> > >
> > > ----- Original Message -----
> > > From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
> > > To: "Geoff" <geoffrey at jeremy.mv.com>; "ARC 5" <arc5 at mailman.qth.net>
> > > Sent: Sunday, November 24, 2013 6:25 PM
> > > Subject: RE: [ARC5] FCC General exam
> > >
> > >
> > > Well, the F1 and F2 layers are at a lower altitude in the day and merge
> > > into
> > > the F layer at a much higher altitude at night.
> > > So the answer should be B.
> > > The propagation depends greatly on frequency.
> > > Find some reference to the ionosphere via google or book.
> > > 73
> > > Bill wa4lav
> > >
> > > ________________________________________
> > > From: Geoff [geoffrey at jeremy.mv.com]
> > > Sent: Sunday, November 24, 2013 6:07 PM
> > > To: Fuqua, Bill L; ARC 5
> > > Subject: Re: [ARC5] FCC General exam
> > >
> > > ----- Original Message -----
> > > From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
> > > To: "ARC 5" <arc5 at mailman.qth.net>
> > > Sent: Sunday, November 24, 2013 5:10 PM
> > > Subject: [ARC5] FCC General exam
> > >
> > >
> > > > Here is a question that I believe they have wrong on the General
> Exam.
> > > > What is the answer with out looking it up.
> > > >
> > > > G3C02 Where on the Earth do ionospheric layers reach their maximum
> > > > height?
> > > > A. Where the Sun is overhead
> > > > B. Where the Sun is on the opposite side of the Earth
> > > > C. Where the Sun is rising
> > > > D. Where the Sun has just set
> > >
> > >
> > > I would choose D. Where the Sun has just set
> > > If discussing the E layer anyway.
> > >
> > > Carl
>
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