|
A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM Keith Morehouse
via MotoG
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply beyond 300 miles. Six and two are not too different with respect to the plot below. Meteor scatter starts to overcome tropo at about 350 miles, depending on station capability. WSJT-X helps, but at those distances MSK144 is probably better than FT8 or FT4 for that path. Typical modest station capability on 2M is about 200dB, less on 6M roughly by the difference in antenna gains.
The difference in large part is due to the height of the scattering media; for troposatter it is about 35,000 ft or below, for meteor scatter is it 60 miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@...>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am trying to work him for new 6M grid and sent him an email about looking this way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
>
>
>
|
|
|
Last week, there were several -days- of 2 meter propagation between Mississippi and Ontario/Western NY, to the west of Dorian. Eat your heart out.
73,
Steve, N2IC
toggle quoted message
Show quoted text
On 09/13/2019 03:29 PM, Keith Morehouse wrote: A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM
Keith Morehouse
via MotoG
On Fri, Sep 13, 2019, 3:08 PM James Duffey <JamesDuffey@... <mailto:JamesDuffey@...>> wrote:
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply
beyond 300 miles. Six and two are not too different with respect to the plot
below. Meteor scatter starts to overcome tropo at about 350 miles, depending
on station capability. WSJT-X helps, but at those distances MSK144 is
probably better than FT8 or FT4 for that path. Typical modest station
capability on 2M is about 200dB, less on 6M roughly by the difference in
antenna gains.
The difference in large part is due to the height of the scattering media;
for troposatter it is about 35,000 ft or below, for meteor scatter is it 60
miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...
<mailto:n2ic@...>> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's
a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ
on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...
<mailto:n5jeh@...>> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation
to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@... <mailto:N7KA@...>>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io <mailto:nmvhf@groups.io>>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am
trying to work him for new 6M grid and sent him an email about looking this
way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
>
>
>
|
|
|
Yes, tropoducting is almost unheard of in the Southwest. Of course, we don’t get the tropical storms either.
James Duffey KK6MC
Cedar Crest NM
toggle quoted message
Show quoted text
On Sep 13, 2019, at 15:35, Steve London <n2ic@...> wrote:
Last week, there were several -days- of 2 meter propagation between Mississippi and Ontario/Western NY, to the west of Dorian. Eat your heart out.
73,
Steve, N2IC
On 09/13/2019 03:29 PM, Keith Morehouse wrote:
A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM
Keith Morehouse
via MotoG
On Fri, Sep 13, 2019, 3:08 PM James Duffey <JamesDuffey@... <mailto:JamesDuffey@...>> wrote:
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply
beyond 300 miles. Six and two are not too different with respect to the plot
below. Meteor scatter starts to overcome tropo at about 350 miles, depending
on station capability. WSJT-X helps, but at those distances MSK144 is
probably better than FT8 or FT4 for that path. Typical modest station
capability on 2M is about 200dB, less on 6M roughly by the difference in
antenna gains.
The difference in large part is due to the height of the scattering media;
for troposatter it is about 35,000 ft or below, for meteor scatter is it 60
miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...
<mailto:n2ic@...>> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's
a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ
on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...
<mailto:n5jeh@...>> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation
to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@... <mailto:N7KA@...>>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io <mailto:nmvhf@groups.io>>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am
trying to work him for new 6M grid and sent him an email about looking this
way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
>
>
>
|
|
|
I do. Until 6 years ago, I was able to take advantage of it.
I recall a bad cold wave around Thanksgiving one year, when the Great Lakes were still warm and ice free. A duct set up over the lakes and up the St Lawrence valley that allowed me to work K1WHS in Maine on 2, 222 & 432, along with VE2's from EN52 - well over 800 miles. And, 2M QSOs all the way to VE1. On 432, I was using a single 9WL yagi at 40' and 200W.
I also had a 'everyday' range of close to 400 miles on 2M troposcatter with a 5WL yagi at 75'. Well set-up rovers could be worked out to 300-350 miles on 6 & 2M. That's actually not too much different from what I see here in DM58. Unfortunately, many local rovers are just not set up for longer haul stuff like they were in the upper Midwest. They mostly have a 'work local' attitude. You would never see serious rovers in IL, WI or MN counting on loops for 6 or 2. The easily worked 6M rovers ran full size antennas, even if it was just a dipole or beam driven element. It made a huge difference.
-W9RM Keith Morehouse
via MotoG
On Fri, Sep 13, 2019, 3:35 PM Steve London < n2ic@...> wrote: Last week, there were several -days- of 2 meter propagation between Mississippi
and Ontario/Western NY, to the west of Dorian. Eat your heart out.
73,
Steve, N2IC
On 09/13/2019 03:29 PM, Keith Morehouse wrote:
> A random observation...
>
> There is troposcatter and then there is tropospheric ducting, which is what most
> VHF+ ops from east of the continental divide (and some west coasters) are
> familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
>
> While troposcatter is a useable propagating mode most anywhere and accountable
> for a good majority of those 300 mile Q's on 10M and above, tropo ducting is
> another animal altogether and rarely appears in areas of drastically variable
> terrain like central and western Colorado. The temperature inversions that
> often (always ??) cause ducting to occur are usually at low enough elevations
> that they are blocked by high terrain. Plus, inversions go hand in hand with
> atmospheric moisture content, something hard to come by in the dry southwest.
> My current humidity here in DM58 is 15%, which actually is high for this time of
> year.
>
> -W9RM
>
> Keith Morehouse
> via MotoG
>
> On Fri, Sep 13, 2019, 3:08 PM James Duffey <JamesDuffey@...
> <mailto:JamesDuffey@...>> wrote:
>
> I was referring to the Olathe-Amarillo path. Tropo losses rise steeply
> beyond 300 miles. Six and two are not too different with respect to the plot
> below. Meteor scatter starts to overcome tropo at about 350 miles, depending
> on station capability. WSJT-X helps, but at those distances MSK144 is
> probably better than FT8 or FT4 for that path. Typical modest station
> capability on 2M is about 200dB, less on 6M roughly by the difference in
> antenna gains.
>
> The difference in large part is due to the height of the scattering media;
> for troposatter it is about 35,000 ft or below, for meteor scatter is it 60
> miles or so. - Duffey
>
>
> James Duffey KK6MC
> Cedar Crest NM
>
> > On Sep 13, 2019, at 13:42, Steve London <n2ic@...
> <mailto:n2ic@...>> wrote:
> >
> > Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's
> a mostly downhill-to-flat path.
> >
> > Olathe-to-Amarillo: 410 miles.
> >
> > For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ
> on 6 and 2.
> >
> > 73,
> > Steve, N2IC
> >
> >> On 09/13/2019 10:29 AM, Arne N7KA wrote:
> >> I am hearing him and decoding.
> >> Arne N7KA
> >>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...
> <mailto:n5jeh@...>> wrote:
> >>>
> >>> MSK 144 would work better for that distance with no other propagation
> to help. Just MHO
> >>>
> >>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
> >>>
> >>> *ED N5JEH DM65RD *
> >>>
> >>> *From: *Arne N7KA <mailto:N7KA@... <mailto:N7KA@...>>
> >>> *Sent: *Friday, September 13, 2019 8:52 AM
> >>> *To: *NMVHF <mailto:nmvhf@groups.io <mailto:nmvhf@groups.io>>
> >>> *Subject: *[nmvhf] DM95
> >>>
> >>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am
> trying to work him for new 6M grid and sent him an email about looking this
> way and into Olathe during the contest this weeked. He is in Amarillo.
> N5EPA might have a good chance, possibly W7QQ.
> >>>
> >>> Arne N7KA
> >>>
> >
> >
> >
>
>
>
>
|
|
|
Guys,
Just erected the 4x9 eme array which I'll use for tropo(n) with the antennas pointing to horizon. So that's added to the limited capability here. So 6, 2, 10 G and 24 G.
GL es have fun.
Duffey; any news with the rove plan?? Anyone else out portable or roving?
Bill W7QQ
On Fri, Sep 13, 2019 at 3:29 PM Keith Morehouse < w9rm@...> wrote: A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM Keith Morehouse
via MotoG
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply beyond 300 miles. Six and two are not too different with respect to the plot below. Meteor scatter starts to overcome tropo at about 350 miles, depending on station capability. WSJT-X helps, but at those distances MSK144 is probably better than FT8 or FT4 for that path. Typical modest station capability on 2M is about 200dB, less on 6M roughly by the difference in antenna gains.
The difference in large part is due to the height of the scattering media; for troposatter it is about 35,000 ft or below, for meteor scatter is it 60 miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@...>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am trying to work him for new 6M grid and sent him an email about looking this way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
>
>
>
|
|
|
Bill - Holy crap that is a killer array!
I sent an itinerary earlier, but I guess it didn’t make it?
Here it is again:
KK6MC/r itinerary ARRL Sept VHF Contest
Grid Time on Time out
September 14, 2019
DM64bw 1800Z 1930Z
In motion, through DM65 to DM55
DM55xh 2030Z 2200Z
In motion through DM55 (+ bit of DM54)
September 15, 2020
DM44ww 0000Z 0200Z
Break for dinner, but we may operate later
Next day local, still Sept 15 local
DM44ww 1300Z 1500Z
We will dedicate this operating period to 6M MSK144
DM45wa 1515Z 1715Z
We will dedicate this operating period to 6M MSK144
DM45wa 1715Z 1800Z
We will dedicate this operating period to SSB & CW
In motion through DM45 and DM46
DM46vc 2000Z 2130Z
In motion through DM46 and DM56
DM56ec 2230Z 0000Z
In motion through DM56, DM55, DM65 (+ a bit of DM64)
DM65 0300Z
end of contest, if we are early we will operate a bit here
WB2FKO whose home station is dismantled in preparation for a move will be operating with me. While we are dedicating most of Sunday morning to MSK144 we will operate FT8 and FT4 when in the other grids. WSJT-X while roving is new to me, so I am still feeling my way around, but we plan on spending roughly the first half hour at a grid on SSB & CW, then the next half hour or so on FT8/FT4 and then what time remains at the end back on SSB and CW. If we get behind schedule we will try to leave on time, which may leave us short of operating time at a grid.
When we have cell access we will be on Slack and APRS. James Duffey KK6MC Cedar Crest NM
On Sep 13, 2019, at 16:51, Bill < bill4070@...> wrote: Guys,
Just erected the 4x9 eme array which I'll use for tropo(n) with the antennas pointing to horizon. So that's added to the limited capability here. So 6, 2, 10 G and 24 G.
GL es have fun.
Duffey; any news with the rove plan?? Anyone else out portable or roving?
Bill W7QQ
On Fri, Sep 13, 2019 at 3:29 PM Keith Morehouse < w9rm@...> wrote: A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM Keith Morehouse
via MotoG
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply beyond 300 miles. Six and two are not too different with respect to the plot below. Meteor scatter starts to overcome tropo at about 350 miles, depending on station capability. WSJT-X helps, but at those distances MSK144 is probably better than FT8 or FT4 for that path. Typical modest station capability on 2M is about 200dB, less on 6M roughly by the difference in antenna gains.
The difference in large part is due to the height of the scattering media; for troposatter it is about 35,000 ft or below, for meteor scatter is it 60 miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@...>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am trying to work him for new 6M grid and sent him an email about looking this way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
>
>
>
|
|
|
Duffey,
No, it made it I was late in seeing it and asked just before I saw it in my cue.
Yes, the EME array has better gain than the stacked yagis, judging by the radio check I had with W9RM.
Will track you and Mike on 2. Sorry I'll not have 222 through 1296.
Have fun es 73 Bill
Bill - Holy crap that is a killer array!
I sent an itinerary earlier, but I guess it didn’t make it?
Here it is again:
KK6MC/r itinerary ARRL Sept VHF Contest
Grid Time on Time out
September 14, 2019
DM64bw 1800Z 1930Z
In motion, through DM65 to DM55
DM55xh 2030Z 2200Z
In motion through DM55 (+ bit of DM54)
September 15, 2020
DM44ww 0000Z 0200Z
Break for dinner, but we may operate later
Next day local, still Sept 15 local
DM44ww 1300Z 1500Z
We will dedicate this operating period to 6M MSK144
DM45wa 1515Z 1715Z
We will dedicate this operating period to 6M MSK144
DM45wa 1715Z 1800Z
We will dedicate this operating period to SSB & CW
In motion through DM45 and DM46
DM46vc 2000Z 2130Z
In motion through DM46 and DM56
DM56ec 2230Z 0000Z
In motion through DM56, DM55, DM65 (+ a bit of DM64)
DM65 0300Z
end of contest, if we are early we will operate a bit here
WB2FKO whose home station is dismantled in preparation for a move will be operating with me. While we are dedicating most of Sunday morning to MSK144 we will operate FT8 and FT4 when in the other grids. WSJT-X while roving is new to me, so I am still feeling my way around, but we plan on spending roughly the first half hour at a grid on SSB & CW, then the next half hour or so on FT8/FT4 and then what time remains at the end back on SSB and CW. If we get behind schedule we will try to leave on time, which may leave us short of operating time at a grid.
When we have cell access we will be on Slack and APRS. James Duffey KK6MC Cedar Crest NM Guys,
Just erected the 4x9 eme array which I'll use for tropo(n) with the antennas pointing to horizon. So that's added to the limited capability here. So 6, 2, 10 G and 24 G.
GL es have fun.
Duffey; any news with the rove plan?? Anyone else out portable or roving?
Bill W7QQ
On Fri, Sep 13, 2019 at 3:29 PM Keith Morehouse < w9rm@...> wrote: A random observation...
There is troposcatter and then there is tropospheric ducting, which is what most VHF+ ops from east of the continental divide (and some west coasters) are familiar with, when 2M and above 'opens' over paths exceeding 3-400 miles.
While troposcatter is a useable propagating mode most anywhere and accountable for a good majority of those 300 mile Q's on 10M and above, tropo ducting is another animal altogether and rarely appears in areas of drastically variable terrain like central and western Colorado. The temperature inversions that often (always ??) cause ducting to occur are usually at low enough elevations that they are blocked by high terrain. Plus, inversions go hand in hand with atmospheric moisture content, something hard to come by in the dry southwest. My current humidity here in DM58 is 15%, which actually is high for this time of year.
-W9RM Keith Morehouse
via MotoG
I was referring to the Olathe-Amarillo path. Tropo losses rise steeply beyond 300 miles. Six and two are not too different with respect to the plot below. Meteor scatter starts to overcome tropo at about 350 miles, depending on station capability. WSJT-X helps, but at those distances MSK144 is probably better than FT8 or FT4 for that path. Typical modest station capability on 2M is about 200dB, less on 6M roughly by the difference in antenna gains.
The difference in large part is due to the height of the scattering media; for troposatter it is about 35,000 ft or below, for meteor scatter is it 60 miles or so. - Duffey
James Duffey KK6MC
Cedar Crest NM
> On Sep 13, 2019, at 13:42, Steve London <n2ic@...> wrote:
>
> Albuquerque-to-Amarillo: 269 miles. Once you get over the Sandia's, it's a mostly downhill-to-flat path.
>
> Olathe-to-Amarillo: 410 miles.
>
> For reference, My QTH in DM52XT to Santa Fe is 240 miles. Can work W7QQ on 6 and 2.
>
> 73,
> Steve, N2IC
>
>> On 09/13/2019 10:29 AM, Arne N7KA wrote:
>> I am hearing him and decoding.
>> Arne N7KA
>>> On September 13, 2019 at 10:20 AM Ed <n5jeh@...> wrote:
>>>
>>> MSK 144 would work better for that distance with no other propagation to help. Just MHO
>>>
>>> Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
>>>
>>> *ED N5JEH DM65RD *
>>>
>>> *From: *Arne N7KA <mailto:N7KA@...>
>>> *Sent: *Friday, September 13, 2019 8:52 AM
>>> *To: *NMVHF <mailto:nmvhf@groups.io>
>>> *Subject: *[nmvhf] DM95
>>>
>>> I copied N5KS on 6M FT8 yesterday with good sigs -8 to -14. I am trying to work him for new 6M grid and sent him an email about looking this way and into Olathe during the contest this weeked. He is in Amarillo. N5EPA might have a good chance, possibly W7QQ.
>>>
>>> Arne N7KA
>>>
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