[Boatanchors] OT: Something I don't understand about 10M propagation

[Steve]

Phil, there is a tropospheric ducting map available here:

http://www.dxinfocentre.com/tropo_wam.html

but I doubt if the mode you are seeing is tropo as it is more effective in 
the VHF / UHF regions and not so much on 10m.

I think there is no doubt that it is Es. Typically, on 50MHz during June / 
July, any Es openings we get in the very late evening are towards JA or more 
often, to KL7, so this would be even more likely on 28MHz where it takes 
even less ionization to produce reflection. About 30 years ago, 100% of the 
JA to NA openings on 50MHz were around midnight but over the years and more 
recently, the openings have been coming earlier.

Early morning Es paths (when they occur) on 6m are also commonly N-S towards 
W6 from here, so what you are seeing is normal for the summer 'short-skip' 
season. You may notice this drops off rapidly after late August and into 
September which would confirm the mode as Es. And you are right...Es is 
pretty random in regards to its sudden appearance but the paths are quite 
consistant once established.

Steve 73



> Thank you Pete,
>
> I'd heard about Sporadic E, but always thought it as a random thing (which 
> apparently it is).  Never considered Tropo though. My career field in the 
> AF was Microwave Radio Relay which also included Tropo Scatter, TXing very 
> high power (1KW to 50kw, I worked on it all) through large dishes in the 
> hopes that some would 'scatter' and be heard at the distant receiver. 
> That was usually in the 900MHz to 1GHz range and I never thought about it 
> possibly having an effect at 28MHz.
>
> But since it is quite consistent each night and morning (with some 
> exceptions) I suspect that it is 'tropo', either scatter or ducting. . .
>
> 73 From "The Beaconeer's Lair"
> Specializing in DXing NDBs (Longwave Beacons)
> Phil, KO6BB,  http://www.qsl.net/ko6bb/
> KO6BB/B beacon, ~20W on 28.290 MHz, Ringo Vertical
>
> On 7/5/2017 6:36 AM, manualman at juno.com wrote:
>> Most likely it's Sporadic E which can happen any time night and day. At
>> 2:30 AM EDT, right now, there's activity up and down the west coast. Also
>> have to consider tropo conditions up and down the west coast. Again,
>> right now, "very intense to strong" from Southern CA to Northern
>> Washington.
>>
>> Pete, wa2cwa
>>
>> On Wed, 5 Jul 2017 06:24:00 +0000 Phil <ko6bb1 at gmail.com> writes:
>>> Hi All,
>>>
>>> First, let me say that I've been "radioactive" in one form or
>>> another
>>> since the early 1950's.  Have a LOT of radio-time under my belt.
>>>
>>> OK, we're basically at the sunspot low and I realize that 10M prop,
>>> for
>>> the most part is rather poor.  Earlier in the cycle it was very
>>> routine
>>> for me to see spots of my beacon from coast to coast, Australia,
>>> DAILY
>>> to Hawaii, etc.  I don't expect to see that now, and am thrilled
>>> when I
>>> see the occasional Hawaii spots of my beacon.
>>>
>>> But one thing puzzles me.  It seems that I almost have a 'pipeline'
>>> to
>>> KU7T in North Bend, WA, and to a slightly lesser extent to K2PO
>>> (Portland OR) (My QTH is Central California). Spots occur to them on
>>>
>>> almost a daily basis (yes a few days go spotless), but what puzzles
>>> me
>>> is not so much the spots, but the time of them.  I would expect 10M
>>> prop
>>> to peak in the midday or late afternoon, or maybe at 'grayline'.
>>> But
>>> not these!  They most often occur WELL after nightfall.  Like
>>> tonight
>>> they are occurring from 0528Z to the present, 0612Z.  That is
>>> 10:28PM to
>>> 11:12PM local time.  They also frequently occur in the morning
>>> between
>>> 1430Z to 1630Z, but NOT later in the daytime like I'd expect. . .
>>>
>>> NOTE:  You can see my spots at the following RBN site, set the "Rows
>>> to
>>> show" button to 100 to see up to 100 spots at a time. NOTE:  On
>>> Friday
>>> Mornings (after midnight?) the database archive is wiped clean and
>>> nothing will be shown until new ones pop up.
>>>
>
>
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