On Sat, 04 Oct 2003 18:06:23 -0700, Roy Lewallen
wrote:

At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL

Don't forget the daytime LF/MF attenuation in the D-layer, by
preventing it from reaching the E-layer, which sets the LUF (Lowest
Usable Frequency). At night, the D-layer disappears, thus, the signal
can reflect from the E or F layer.

At least the 77,5 kHz Maiflingen standard time transmitter in Germany
is usable to about 2000 .. 2500 km from the transmitter during the
night at least in the winter. However, during the summer nights, the D
layer is in constant sunlight all night nearly 1000 km south of the
arctic circle, which may explain the worse conditions during summer
night, but of course the number of lightnings is also higher during
the summer, increasing the band noise.

Paul OH3LWR

I'm not at all an expert on propagation. So are you saying that
propagation of 60 kHz signals is via ionospheric skip? E or F layer? I
didn't think the LUF ever got anywhere near 60 kHz at any time.

Roy Lewallen, W7EL

Paul Keinanen wrote:
On Sat, 04 Oct 2003 18:06:23 -0700, Roy Lewallen
wrote:


At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL


Don't forget the daytime LF/MF attenuation in the D-layer, by
preventing it from reaching the E-layer, which sets the LUF (Lowest
Usable Frequency). At night, the D-layer disappears, thus, the signal
can reflect from the E or F layer.

At least the 77,5 kHz Maiflingen standard time transmitter in Germany
is usable to about 2000 .. 2500 km from the transmitter during the
night at least in the winter. However, during the summer nights, the D
layer is in constant sunlight all night nearly 1000 km south of the
arctic circle, which may explain the worse conditions during summer
night, but of course the number of lightnings is also higher during
the summer, increasing the band noise.

Paul OH3LWR

I'm not at all an expert on propagation. So are you saying that
propagation of 60 kHz signals is via ionospheric skip? E or F layer? I
didn't think the LUF ever got anywhere near 60 kHz at any time.

Roy Lewallen, W7EL

Paul Keinanen wrote:
On Sat, 04 Oct 2003 18:06:23 -0700, Roy Lewallen
wrote:


At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL


Don't forget the daytime LF/MF attenuation in the D-layer, by
preventing it from reaching the E-layer, which sets the LUF (Lowest
Usable Frequency). At night, the D-layer disappears, thus, the signal
can reflect from the E or F layer.

At least the 77,5 kHz Maiflingen standard time transmitter in Germany
is usable to about 2000 .. 2500 km from the transmitter during the
night at least in the winter. However, during the summer nights, the D
layer is in constant sunlight all night nearly 1000 km south of the
arctic circle, which may explain the worse conditions during summer
night, but of course the number of lightnings is also higher during
the summer, increasing the band noise.

Paul OH3LWR

On Sat, 04 Oct 2003 18:06:23 -0700, Roy Lewallen
wrote:

At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL

Don't forget the daytime LF/MF attenuation in the D-layer, by
preventing it from reaching the E-layer, which sets the LUF (Lowest
Usable Frequency). At night, the D-layer disappears, thus, the signal
can reflect from the E or F layer.

At least the 77,5 kHz Maiflingen standard time transmitter in Germany
is usable to about 2000 .. 2500 km from the transmitter during the
night at least in the winter. However, during the summer nights, the D
layer is in constant sunlight all night nearly 1000 km south of the
arctic circle, which may explain the worse conditions during summer
night, but of course the number of lightnings is also higher during
the summer, increasing the band noise.

Paul OH3LWR

Roy Lewallen ) writes:
At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL


Roy,

I believe that even at 60 kHz, propagation is within an earth-ionosphere
waveguide, the height of which is controlled by the sun (60 km during
daylight and 90 km during night).

Precise RF phase comparison is easy at these freqs because the phase
stability of the path is excellent during all daylight conditions, but
there is some random variation at night. It is best to avoid making
measurements (of phase) while the path is only partly in daylight because
of the diurnal shifts in phase as the sunrise-sunset terminator passes
over the radio path (due to the changing height of the waveguide).

The U.S. VLF OMEGA navigation system, the old WWVL (now SK) on 20 kHz, MSF
on 60 kHz, and WWVB on 60 kHz all suffer from these effects.

73,
.... Martin VE3OAT

For those interested in getting full and complete details of WWVB, go to:

http://www.boulder.nist.gov/timefreq/stations/wwvb.htm

That is the home page for the NIST radio stations and there is a link to
NIST's radio coverage every two hours or so during a 24 hour period
using small hemispere map projections of North and South America.

---

What I am personally interested in is a source for the direct conversion
of WWVB field strength from or to Volts per Meter to confirm the 60 KHz
loop antenna constructed a year ago here. I have a particular reason
since there is some shading effects of nearby-to-residence San Gabriel
Mountain range. Reception is fine, I'm just trying to tie others' numbers
of field strength into the equations for a magnetic loop.

Len Anderson
retired (from regular hours) electronic engineer person

For those interested in getting full and complete details of WWVB, go to:

http://www.boulder.nist.gov/timefreq/stations/wwvb.htm

That is the home page for the NIST radio stations and there is a link to
NIST's radio coverage every two hours or so during a 24 hour period
using small hemispere map projections of North and South America.

---

What I am personally interested in is a source for the direct conversion
of WWVB field strength from or to Volts per Meter to confirm the 60 KHz
loop antenna constructed a year ago here. I have a particular reason
since there is some shading effects of nearby-to-residence San Gabriel
Mountain range. Reception is fine, I'm just trying to tie others' numbers
of field strength into the equations for a magnetic loop.

Len Anderson
retired (from regular hours) electronic engineer person

Roy Lewallen ) writes:
At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL


Roy,

I believe that even at 60 kHz, propagation is within an earth-ionosphere
waveguide, the height of which is controlled by the sun (60 km during
daylight and 90 km during night).

Precise RF phase comparison is easy at these freqs because the phase
stability of the path is excellent during all daylight conditions, but
there is some random variation at night. It is best to avoid making
measurements (of phase) while the path is only partly in daylight because
of the diurnal shifts in phase as the sunrise-sunset terminator passes
over the radio path (due to the changing height of the waveguide).

The U.S. VLF OMEGA navigation system, the old WWVL (now SK) on 20 kHz, MSF
on 60 kHz, and WWVB on 60 kHz all suffer from these effects.

73,
.... Martin VE3OAT

At 60 kHz, there shouldn't be any difference between daytime and
nighttime propagation. Certainly the ionosphere isn't involved.

Roy Lewallen, W7EL

Jack Twilley wrote:
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Hash: SHA1


"Roy" == Roy Lewallen writes:


Roy The noise was lower late at night when more gadgets were off,
Roy which I'm sure is why the automatic clocks you can get now do
Roy their synchronizing late at night.

I thought the reason they sync'ed at night was because of propagation.

Interesting.

Jack.

The noise was lower late at night when more gadgets were off,
which I'm sure is why the automatic clocks you can get now do
their synchronizing late at night.

I thought the reason they sync'ed at night was because of propagation.

I've occasionally "played" with an "atomic clock" by setting it INcorrectly,
and each has always sync'ed within 10 minutes at ANY time of the day, except
for one which was inside a metal building; it finally sync'ed about noon.

I'm near Topeka, KS, some 400+ miles east and a little south of Boulder, CO.

--Myron, W0PBV.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)