[Elecraft] transverter bands question
Kenneth E. Harker
[email protected]
Mon Dec 8 17:52:25 2003
On Mon, Dec 08, 2003 at 03:58:56PM -0600, John Cooper wrote:
> As many of you already know Im a relatively new ham with a K2. For 6M 2M bands I know you basically have to wait for a good opening from what Ive read thus far in QST. Are these daytime or nighttime bands. Generally in my exp 80 is good at night only 40 both cept for shortwave killing it at night. 20-10 good in the day not so active at night. Not to say I have not worked stations at these times but Im asking whats the times of major activity for 6m 2m sideband.
Any time of day for troposhperic forward scatter (out to about 350 miles
or so on average.) The troposphere is a little quieter in the evenings (well
after sunset) and the mornings, but the differences are really between
propagation to 300 miles or propagation to 400 miles - not such a big
difference. It can be dependent on weather, too - the calmer your part of the
country is, the better tropo forward scatter is. Tropo forward scatter
is applicable to all the VHF/UHF bands.
On six meters, the most common form of propagation is Eskip, or "sporadic E."
Very dense clouds of ionization form in the E layer of the ionosphere and
reflect signals from sometimes as low as 14 MHz to sometimes as high as 144
MHz. Propagation distance on a single hop is 500-1500 miles on average.
Sometimes conditions are good and you can get two hops. In the months of
May-Aug, Eskip is frequent - in June, you may get Eskip openings two days
out of three on six meters. There is also a minor Eskip season in
mid-January. The most common times of day for Eskip are local mornings
and local evenings (dusk to 11PM or so.) Nevertheless, Eskip can occur
any time on any day. Activity levels, though, dictate that evenings are
best time to be on the air.
On two meters, the most common form of propagation is tropospheric ducting.
This is when layers of warm and cold air cause ducts that radio signals
get refracted into and out of. Ducts can form over distances of several
hundred miles. They are most likely to form in the fall, centered on
very slow moving high pressure systems. Having the path over water helps.
The Texas-Florida path commonly gets ducts that time of year, as do
Florida-New England and California-Hawaii. But, ducts can and do happen
over entirely land paths as well. Ducts can happen any time of day, but
activity levels are higher in the evenings, after people get home from work.
Aside from propagation, the big thing to get used to on VHF/UHF is the
highly directional antennas that everyone uses. If you can put up a yagi
on either band, get used to turning it a lot to look for other stations.
30 degrees can make a huge difference in received signal strength.
> Thanks
> WT5Y
>
> This is has been my most helpful resource since Ive been licensed. Thanks Wayne and Eric!
>
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Kenneth E. Harker "Vox Clamantis in Deserto" [email protected]
University of Texas at Austin Amateur Radio Callsign: WM5R
Department of the Computer Sciences Central Texas DX & Contest Club
Taylor Hall TAY 2.124 Maintainer of Linux on Laptops
Austin, TX 78712-1188 USA http://www.cs.utexas.edu/users/kharker/
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