[VHFcontesting] Ionosphere Scatter

Sean Waite waisean at gmail.com
Mon Oct 24 13:59:04 EDT 2016

WSJT has ISCAT and JT6M that can be used on the mode. It doesn't look like
they are in WSJT-X yet.

I'm assuming with sufficient power and gain the answer is "whatever mode
you want."

I'll have to read that fairly sizable document when I'm off work.

It doesn't seem like it's a mode that can be done with any reasonable
equipment that a rover might carry, which is unfortunate. At best we'd have
a 4el super moxon and 100W on 6. Some friends and I are considering in the
next year or three to start getting out occasionally for grid expeditions
to some of the rarer grids in Maine, New Hampshire and Massachusetts (FN45,
FN56, FN67, FN51 and that area). In addition to trying to get more contacts
on our contest roves, being able to get any sort of propagation when on the
wrong side of Maine will be the key to success on those trips. If we can
hit ionosphere scatter or tropo scatter with 100W and 5el on 6 then those
will be an option.

I have to assume that ISCAT is similar to FSK441 and MSK144 for meteor
scatter, just tweaked to handle the idiosyncrasies of the method of

The reading I've done where it proves interesting during the daytime is
what drew my attention. Without Es we're fairly limited in range on the VHF
bands and MS and EME aren't usually an option when the sun is shining. It
may even be that once some of the bigger VHF stations start looking around
on these modes - maybe during the quieter hours of contests - that those of
us roving will be able to work them with much more modest stations. Likely
though, as the modes are pretty slow the bigger stations won't have the
slow down that the little guys do and it won't be interesting for them.

Sean WA1TE

It seems like this is fairly new territory for a lot of people

On Mon, Oct 24, 2016 at 1:27 PM PAUL ROLLINSON <paulrollinson at sbcglobal.net>

> Excuse the ignorance but what mode (software) do you use? From the
> article/paper it appears MS and IS are very similar in make-up but
> different natural enhancements to create the path.
> I've done some MS...great in the winter when you want to heat the shack.
> Is it similar?
> I would love to play around with it in a non-contest setting.
> Thanks & &73
> Paul Rollinson, KE1LI
> FN14AU
> 860-928-5147 <(860)%20928-5147>
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> ------------------------------
> *From:* N1BUG <paul at n1bug.com>
> *To:* Sean Waite <waisean at gmail.com>; VHF Contesting <
> vhfcontesting at contesting.com>
> *Sent:* Monday, October 24, 2016 10:30 AM
> *Subject:* Re: [VHFcontesting] Ionosphere Scatter
> Hi Sean,
> I am no expert by any means but I can share an anecdote or two.
> I became interested in ionoscatter at 144 MHz after talking to
> SM2CEW and other Europeans about it. For a period of time in the
> early 1990s I ran daily or almost daily skeds with big stations in
> the midwest. I was running 1500 watts and 20 to 21 dB antenna gain.
> My antenna was an EME array, quite low and blocked by trees so I may
> have suffered some there. This was all using CW. Most skeds were at
> noon or close to it. Earlier or later signals were not as good.
> I could work KB8RQ at 836 miles almost every day. Actually I don't
> recall any days we tried and failed. Some days it was a struggle,
> other days signals were very solid 539. A couple of times we
> switched to SSB and were able to communicate. KB8RQ was running 1500
> watts to an array with gain somewhere in the 26-30 dB range!
> On the better days I could work stations with 20 dB gain at similar
> distances. On the very best days I could just barely eke out a QSO
> (callsigns, signal report, RRR) with K0IFL at something over 1200
> miles (I have forgotten the exact distance, though 1220 miles seems
> to keep floating around my brain as I think about this). K0IFL had
> 20 to 21 dB antenna gain.
> Perhaps you can roughly extrapolate what is possible on digital
> modes from this. I have no idea.
> I must say it was fun being able to work 800+ miles every day on 2
> meters! If I ever get that much power and antenna gain again, I
> would like to continue to play with this fascinating propagation mode.
> 73,
> Paul N1BUG
> On 10/24/2016 10:02 AM, Sean Waite wrote:
> > Hi everybody,
> >
> > I see that WSJT has an "ISCAT" mode for ionosphere scatter. I can't find
> > much about how to operate in this mode, or even much about ionosphere
> > scatter in general.
> >
> > I gather that it's a daytime mode, best at noon and loves it when the K
> > index is high. I also see things about how the military used to do it
> with
> > 40kW transmitters through 20dB gain antennas. I'm a few dB short of that
> on
> > most bands.
> >
> > OZ1RH has an article on qsl.net (
> qsl.net/qz1rh/ionoscatter_lecture_2002.htm)
> > where he has a little info on it, but not much about what mode he was
> using
> > and given the age I doubt he's using any of the JT modes. He suggests 1kW
> > with a 12dBd antenna may be possible on 6m, but I'm hoping with the ISCAT
> > mode a lesser station could do it, and maybe even 2m.
> >
> > I can't find much about whether the antenna requires elevation.
> >
> >  He does suggest that it has a sweet spot of around 1000-1800km, which I
> > think puts it beyond the reach of meteor scatter. Is this a mode that is
> > ever used in the contests? Does anyone have any additional information
> > about it?
> >
> > Thanks and 73,
> > Sean Waite, WA1TE
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