[VHFcontesting] Ionosphere Scatter

Barry Hansen barry at k7bwh.com
Mon Oct 24 14:45:05 EDT 2016

I follow this thread with interest. I make grid expeditions around the
Pacific Northwest and am always looking for ways to expand the range when
the bands are otherwise closed. There are some rare grid squares that
desperately need activating.

As a rover, I've been known to carry 1 KW and a good 5-element yagi (11
dB) antenna on 6, and something similar on 2. Meteor scatter is tempting
but contacts tend to take a long time. I operate like a mountain-top
portable station but in contests I move around just enough to enter the
rover category.

Barry K7BWH

-----Original Message-----
From: VHFcontesting [mailto:vhfcontesting-bounces at contesting.com] On
Behalf Of Sean Waite
Sent: Monday, October 24, 2016 10:59 AM
To: PAUL ROLLINSON <paulrollinson at sbcglobal.net>; N1BUG <paul at n1bug.com>;
VHF Contesting <vhfcontesting at contesting.com>
Subject: Re: [VHFcontesting] Ionosphere Scatter

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
> 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>
> 860-928-3844 <(860)%20928-3844> Fax
> 860-208-8814 <(860)%20208-8814> Cell/Text Paulrollinson at sbcglobal.net
> Representing Component Part
> Manufacturers for over 35 years
> ------------------------------
> *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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