> -----Original Message-----
> From: propagation-bounces@contesting.com
> [mailto:propagation-bounces@contesting.com]On Behalf Of David Ackrill
> Sent: Sunday, September 26, 2004 6:00 PM
> To: 'propagation'
> Subject: RE: [Propagation] Critical vs. Maximum Usable Frequency map
>
>
>
>
> -----Original Message-----
> >Tomas:
>
> >How does the MUF map predict availablity of a DX path
> >for 80 Meter QSOs (which was the original question),
> >or for 160 Meters?
>
>
> Be fair, the original question was something like "why are there lots of
> signals when the propagation prediction software says the band is dead".
>
> Maybe I misunderstood? Do you mean that there was lots of DX (over, say,
> 3000kM) signals on the band in question?
>
> If so, I apologise, I misunderstood what you were saying. Maybe if you can
> say what countries were being heard, at what time, and where you/your friend
> are located, then someone with more knowledge of propagation on LF can help.
>
> De dave (G0DJA)
>
Dave:
Here was the original question, which wasn't mine:
>> Hi,
>>
>> This morning I was explaining the HFProp program to
>> another ham over the phone. I noticed the program
>> showed there were no propagation on 3.5 MHz, and he
>> countered that he could hear all kinds of S9 signals.
>> What progagation mode does these near vertical signals
>> use, and why don't propagation programs show them?
>> Same on 160 and to a lesser extent on 40.
>>
>> 73, Chas, W1CG
So, in fact, Chas was asking about NVIS, and I'm sorry for
jumping the gun.
There are, however, plenty of DX signals (3000 kM and more)
on 80M and 160M during hours of darkness this time of the
year/cycle, and many DXers who are working DX on these bands.
I was wondering if any of the online realtime charts have
any relevance to the lowband DXer.
Tomas replied with the following useful information:
**********************************************************
> How does the MUF map predict availablity of a DX path
> for 80 Meter QSOs (which was the original question),
> or for 160 Meters?
http://solar.spacew.com/www/160pred.html
This question (propagation on 80 and 160, and models used to forecast) is
not addressed well in the VOACAP/IONCAP models. There are other models
that some software offerings incorporate to help in detailing signal paths
for MW propagation. Proplab and SnapMAX are two such examples. The
creator of ACE did incorporate some E-layer modeling, and was the creator
of a DOD LF/MW version of what you see in the ACE software.
This question does bear some exploring. I'm sure there are others on this
reflector that can add to this discussion.
Are you familiar with NM7M and his discussions, books, and papers on
top-band propagation?
73 de Tomas, NW7US (AARØJA/AAAØWA)
**********************************************************
73,
Jeff Maass K8ND
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