At 85 ft your patterns will be as follows:
Lobe 3 to 9 degrees (1600 to 2300 miles)
Lobe 15 to 20 degrees (900 to 1200 miles)
NULL 10 to 14 degrees (1200 to 1600 miles)
Lobe 4 to 11.5 degrees (1300 to 2000 miles)
Lobe 20 to 27 degrees ( 700 to 900 miles)
NULL 12 to 20 degrees ( 900 to 1300 miles)
Lobe 5 to 18 degrees (1000 to 1900 miles)
Lobe 31 to 41 degrees ( 450 to 600 miles)
NULL 19 to 30 degrees ( 600 to 1000 miles)
Notice the SUBSTANTIAL NULLS at the mimimum
to mid skip distances on each band.
Now look at the patterns at 45 ft
10M Lobe 5 to 18 degrees ( 1000 to 1900 miles)
15M Lobe 6 to 22 degrees ( 850 to 1800 miles)
20M Lobe 9 to 37 degrees ( 500 to 1500 miles)
Notice that the short distances correspond to the
typical skip distances for each band. In other words,
a high band antenna at 45 ft will give the MAXIMUM
coverage for domestic contests.
(FWIW, during daylight hours I notice that my LOW
antennas are usually much better for DX than my 75 to 95 ft
high antennas on the high bands. During darkness, the high
antennas are of course better for DX.)
>From Alabama to New England (800 miles) my TH7 at 40 ft
is usually 20 dB stronger than my TH6 at 80 ft.
NO SINGLE ANTENNA HEIGHT will cover ALL of the
angles supported by the ionosphere.
Your BEST configuration would be a 2L40 and tribander
at 87 ft and another tribander at 40 to 45 ft. (and another
lower dipole or inverted vee at 50 ft for local coverage on 40M)
de Tom N4KG
On Tue, 2 Nov 1999 21:15:44 -0800 "Dan Levin" <firstname.lastname@example.org> writes:
> I finally decided to toss the old tribander and buy a C-3E. I'm
> that Tom gets it to me in time for SS SSB. I'll have it at the top
> of the mast at about 85'.
> I was driving home tonight from dinner and realized that for the 10
> contest, I could throw together a 2 or 3 element 10 meter monobander
> and mount it at the bottom of the mast, say 71'. 14' of separation
> isn't really enough, but it will be worth modeling. NOT
> But - will it work? I don't have a Stackmatch, so I'd have to feed
> them with 1/4 wave phasing lines. About all I really understand
>about stacking is that it works much better with identical antennas
> anyone have any thoughts on whether I can stack a beta matched 3
> monobander with a C-3E in this manner and get it to work? I'd
> comments or suggestions!
Can you GUESS the phase relationship between a
BETA match and a split dipole feed? I can't. N4KG
> Thanks much,
> ***dan, N6BZA
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