Massive tropo across the Gulf...

[DeadElvis]

Oh, how I long for my days with antennas in Pascagoula! Ducting across the Gulf is something to behold.

Those of you anywhere along the Gulf should keep an ear out for nice conditions over the next few days. I have seen some folk's loggings of TV/FM to around 1000 miles in the past 24 hours, all through the troposphere; that means hi-VHF and UHF stuff, too.

What's wacky is that this isn't terribly rare. Forecasts show it may last, to varying degrees, for the next few days.

Enjoy.

DE

 

[RFLA]

> Oh, how I long for my days with antennas in Pascagoula!
> Ducting across the Gulf is something to behold.
>
> Those of you anywhere along the Gulf should keep an ear out
> for nice conditions over the next few days. I have seen
> some folk's loggings of TV/FM to around 1000 miles in the
> past 24 hours, all through the troposphere; that means
> hi-VHF and UHF stuff, too.
>
> What's wacky is that this isn't terribly rare. Forecasts
> show it may last, to varying degrees, for the next few days.
>
>
> Enjoy.
>
> DE
>


Wasn't too impressive this morning IMO..Just my "normal" signals from Alexandria,La. (2 stations that broadcast on 1000+ foot sticks) and all the locals from the west of me (Lafayette/Lake Charles) into Thibodaux,La.

RFLA

 

[_Jim]

Troposphere - lowermost portion of Earth's atmosphere

From Wikipedia:

The troposphere is the lowermost portion of Earth's atmosphere and the one in which most weather phenomena occur. The greenhouse effect also occurs in the troposphere.

The troposphere starts at the earth's surface and extends to an altitude of 16-18 km over tropical regions, decreasing to less than 10 km over the poles. This layer contains approximately 80% of the atmosphere's total mass. Generally, jets fly near the top of this layer. The troposphere is directly below the stratosphere.

- - - - -

Just had to throw that in there.

A lot of people might be thinking 'stratosphere' or 'E' layer skip, but
tropo is due to 'ducting' of a radio signal between various stratified
layers/fronts in the atmosphere from such factors as warm air overrunning
cold air or differences in mid-level air mass content due to it being
vry moist or quite markedly different in temperature.

 

[k9ez]

Re: Troposphere - lowermost portion of Earth's atmosphere

> From Wikipedia:
>
> The troposphere is the lowermost portion of Earth's
> atmosphere and the one in which most weather phenomena
> occur. The greenhouse effect also occurs in the troposphere.
>
>
> The troposphere starts at the earth's surface and extends to
> an altitude of 16-18 km over tropical regions, decreasing to
> less than 10 km over the poles. This layer contains
> approximately 80% of the atmosphere's total mass. Generally,
> jets fly near the top of this layer. The troposphere is
> directly below the stratosphere.
>
> - - - - -
>
> Just had to throw that in there.
>
> A lot of people might be thinking 'stratosphere' or 'E'
> layer skip, but
> tropo is due to 'ducting' of a radio signal between various
> stratified
> layers/fronts in the atmosphere from such factors as warm
> air overrunning
> cold air or differences in mid-level air mass content due to
> it being
> vry moist or quite markedly different in temperature.
>


Actually the E layer is in the Ionosphere. Which is above the stratosphere

 

[_Jim]

Re: Troposphere - lowermost portion of Earth's atmosphere

>
>
> Actually the E layer is in the Ionosphere. Which is above
> the stratosphere
>

As I said, a lot of people might be thinking 'stratosphere'
or 'E' layer skip, but tropo is due to 'ducting' of a radio
signal between various stratified layers/fronts in the
atmosphere from such factors as warm air overrunning
cold air or differences in mid-level air mass content due
to it being very moist or quite markedly different in
temperature.

The most dramatic event I personnally ever participated in
was when we had an unusual ducting event occur off to the
west from where I was near St. Joseph Mich where I was
working for Heathkit at the time and I had checked out
for evaluation a Wilson HT.

The 2M band opened due to troposphereic ducting like I
had never see it before. I was able to work 2M machines
across the lake with that HT with ease. Airline distances
on the order of 70 to 80 miles.

From the Heathkit plant on a clear day along the high
banks of Lk Michigan it is possible to see top of the
Sears Tower and hear the 146.88 'CARA' (sp?) system in
Chicago.

But as this was well before the day programmable PL
or CTCSS tones, I never had a chance to work it (it
was a closed PL access system at the time.)

I witnessed another event using a synthesized Motorola
Motrac accomplished by using a VHF Engineering
Synthesizer II. This allowed 5 KHz steps on a 40 Watt
commercial class radio before even the Icom IC-22S was
available.

Travelling down I-69 into Indiana from Mi. I was
able to bring up several .94 and .88 machines
at the same time from downstate Ohio and Indiana.
This was the time before widespread CTCSS use
on 2M machines, and it seems most coordinating
bodies now require CTCSS/PL as a condition to
being 'coodinated', denying the working of more
than one 2 Meter machine during a tropo opening.

I also operated and worked many an E-skip opening
on 52.525, the 6 FM calling freq, to various parts
of the country. A remote base off from a 450 rptr
helped out there, its a little tough to catch some
of those sproradic E openings that happened randomly
on six if one was out biking, shopping or at the
library (pre internet days).

_Jim - Licensed amateur for nearly 30 years now
and designer of the 6 M Heliax duplexer.

 

[DeadElvis]

Re: Troposphere - lowermost portion of Earth's atmosphere

> The most dramatic event I personnally ever participated in
> ... where I was working for Heathkit at the time and I had checked out
> for evaluation a Wilson HT.

Ham here, too. 1x2 N call. Not to get too deep into tropo stories-- But, I'll give you an HT example...

I spent many years on the Gulf Coast where tropo is jaw-dropping. Conditions can set in for days, and just go and go. Hundreds and hundres of miles over the water is just not uncommon.

Anyway, a couple of years ago, I was visiting Gulf Shores, AL, staying on a second story. I turned on my HT, hoping to get into the Mobile, AL repeater. "Funny," I thought, "the courtesy tone sounds different." It turned out to be Albany, GA, at 228 miles. I was, I was told, full quieting off my HT on the duckie. Fun.

> I also operated and worked many an E-skip opening
> on 52.525, the 6 FM calling freq, to various parts
> of the country. A remote base off from a 450 rptr
> helped out there, its a little tough to catch some
> of those sproradic E openings that happened randomly
> on six if one was out biking, shopping or at the
> library (pre internet days).

6m is my favorite band. But, speaking of HTs, I worked a 700-mile Es contact on 52.525 off my HT once. Again, just the duckie. I wouldn't recommend trying an HT as a primary radio, but it was fun as a lark.

DE