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Moobounce and VHF DX Info
MOONBOUNCE ?! VHF DX?! --- SHHH -- IT'S A SECRET!!! Well,
not any more! Do you mean to tell me that everyone has been lying
to me all these years?! Do VHF/UHF/SHF radio waves in fact bend
and follow the curvature of the earth? You mean I can work Montreal
from Toronto DIRECT!!!
With today's technologies, things have never been easier!!!!
In fact APRS, SSB, FM and CW are all modes that can be used to
work DX on any of our VHF UHF or SHF bands...
And you don't need and Advanced License to find happiness
in Amateur Radio -- heck you may even be able to use it to learn/improve
your CW capabilities!!
HERE's THE STORY!
AURORAL PROPAGATION
The ghostly whispers of Auroral SSB come sneaking out of the
speaker.... SHHHSSSHH CQ DX this is WA4XYZ in North Carolina calling
CQ DX 2 metres --- yup believe it.... you too can work long haul
DX on 144 Mhz, 220 Mhz and even 432 Mhz without getting an Advanced
License. You will need some basic equipment - a multimode VHF
radio, about 100 watts of power and a directional yagi antenna
horizontally polarized. Auroral events happen with great frequency
during the early part of the solar cycle and during the latter
days as well. Looking for auroral displays in the northern sky
is one clue to an event. Other clues include - the blackout of
HF propagation, very enhanced north south signals on 28 Mhz or
14 Mhz - watery fluttery signals on 14 and 3.5 Mhz. When the HF
bands go dead , get on VHF, point your antenna north and call
CQ..... some nights you just cant get any sleep because the pile
up on you is endless...
AURORAL - E - SKIP
Work across Canada on 50 Mhz using the auroral curtain as
a means of propagation! SIX metres offers some interesting enhancement
-- the degree of ionization due to auroral events can be so high
that propagation takes on long haul multihop E layer chanacteristics
-- signals lose their ghostly distortion and become totally clear
-- VE1 stations work into VE7 land, VE6's work into VE3 land.
Stations in Greenland work into VE2 and VE3... the possiblities
are endless -- and we still haven't found just how far the signals
really go!
SPORADIC E PROPAGATION
This is the same mode that drives 10 metres and 11 metres!
Twice a year, during the summer months and during December, the
VHF bands (50 through 225 MHz) can open over distances of 1000
- 3000 Km via Sporadic E.
E Skip signals are very strong at times, can vary wildly in
strength and duration and can move around - one minute the 2 metre
band can be open to Florida and Cuba -- and then presto it can
open to Texas or Bermuda or beyond!.
F LAYER DX at VHF - WORK THE WORLD on 50 Mhz
One of life's experiences in Amateur Radio is working your
first DX. But why wait till you get your HF license to experience
the thrill of working around the world. Our sun is going through
it's 11 year cycle of activity and we are approaching the maximum
of Solar Cycle 23. Canadian Amateurs are already working the globe
on 6 metres, during the fall of 1999 and in the first few weeks
of 2000. You can do it too!!! All you need is the interest to
try it -- 10 watts and a dipole is not too little to work DX on
the "Magic Band". Just remember, SSB and CW are very
efficient modes of modulation, as we have know for decades at
HF-- at VHF it helps even more. (see you don't need CW...)
Listen to BBC TV - Channel 1 (42 MHz) via the F layer, as
heard in Toronto by VE3DSS during Cycle 21, on a "dipole"!bbc1.ra
EARTH- MOON -EARTH (EME) - aka MOONBOUNCE
For those with even more guts (or as Warren Miller oft puts
it -- those who don't know any better) you can work DX at VHF
almost any time you want by bouncing your signal off the moon!Now
the challenge here is to do it with adequate antenna gain -- that
means 2 long yagis at a minimum and anywhere from 250 to 1000
watts of power. (I've done it with a single yagi, as have others,
but you really need to up your Effective Radiated Power to make
a long term presence.)
TROPO DX
Back on earth, you can take advantage of the summer
months and fall to catch tropo conditions and ducting along frontal
systems as they move across the country. During those sweltering
hot days when the smog levels are high, it isn't just smog that
can be trapped near the ground but radio waves too.
METEOR SCATTER
The earth is being bombarded with space debris all
the time. When this stuff burns up in the atmosphere, it leaves
a bright trail that you can see, and that trail is also a column
of ionized gas that will support radio propagation at 50 Mhz,
144 Mhz, 220 Mhz and even 432 Mhz. By hanging out on the calling
frequencies during periods of Meteor Shower activity, you can
work dozens of stations over distances of 1800 km with ease.
TRANS EQUATORIAL SKIP
TE is accessible from Canada -- and no you don't need
to pack up your gear and move to Florida! You just have to time
things right -- TE events occur often during the peak of the solar
cycle -- Sporadic E can help get VE/VA/VY signals far enough south
that they can then couple into the TE - and viola Aregntina on
50 Mhz with S9 thumping loud signals both ways!
FAI
This is real exotic stuff - Field Aligned Irregularites
-- Signals are weak and you need to be able to elevate your antenna
to work it.
AIRPLANE SCATTER
Try tracking and airplance and using it to bounce
a signal -- just like RADAR
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of Contents
Last Updated February 15,
2000 by Dana Shtun P. Eng, Director