[Antennas] Antenna Suggestions

2002年5月28日 13:57:55 -0700

George,
	If the 88ft EDZ tunes up nicely on 10, what is compelling you to
install a 44ft EDZ for 10? Are you going for the radiation pattern?
Thanks
Jan (VA7JNR)
PS Your contributions are always very enlightening. Thanks.
> -----Original Message-----
> From: George, W5YR [mailto:[email protected]]
> Sent: Tuesday, May 28, 2002 10:55 AM
> To: Duncan Cameron
> Cc: [email protected]
> Subject: Re: [Antennas] Antenna Suggestions
>>> Let me be the first to second Duncan's recommendation of the Extended
> Double Zepp antenna. I use two of them - designed for 20 
> meters - mounted
> at right angles for essentially full coverage. Makes a very effective
> "rotary" arrangement. The key is to make the feedlines the 
> same length so
> that the same tuner settings work for either antenna. Then changing
> direction is just a matter of flipping the tuner selector switch.
>> I have used the EDZ on other bands and generally found that the actual
> lengths of either the flattop or the feedline are not at all critical.
> Anything within a foot or so of the design length will work 
> fine. Since the
> antenna itself is non-resonant in any band, the length is just not
> critical. 
>> Presently, my 20 meter EDZ's are about 88 feet long, and they 
> tune up very
> easily from 80 through 10 meters. I intend to put up a 44 foot version
> designed for 10 meters and use it primarily for 17,12 and 10 meters.
>> Another antenna that I just put up a few weeks ago is proving 
> to be a real
> champ on 20 meters. It is an "almost" full-wave loop on 80 
> meters in the
> form of a tilted triangle with the apex at 40 feet and the base of the
> triangle at 10 feet. It is fed in the center of the base with 
> ladderline
> for horizontal polarization. 
>> The radiation patterns from EZNEC are very encouraging for 
> 20-10 with some
> good low-angle lobes on the higher bands. Of course, on 80 and 40, the
> antenna is so low that it is essentially non-directional. On 
> 20 it shows
> some directivity but not enough to pose a lobing problem. 
> Gain is that of a
> dipole or better on 20 and above. Interesting antenna . . .
>> 73/72/oo, George W5YR - the Yellow Rose of Texas 
> Fairview, TX 30 mi NE of Dallas in Collin county EM13qe 
> Amateur Radio W5YR, in the 56th year and it just keeps getting better!
> QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771 I-LINK 11735
> Icom IC-756PRO #02121 Kachina 505 DSP #91900556 Icom IC-765 #02437
>>> Duncan Cameron wrote:
> > 
> > Michael-
> > Something I have used and can highly recommend, is the 
> Extended Double Zepp.
> > (Just a long dipole fed with ladder line) Here are some 
> dimensions that I
> > have used. Just feed it in the center with either 450 ohm 
> or 300 ladder line
> > to your tuner, or you can terminate the ladder line just 
> outside the shack
> > with a 4:1 current balun and go into the tuner with coax.
> > Here are the dimensions-
> > 30 meters=59 feet 5 inches each leg
> > 20 meters= 42 feet 4 inches each leg
> > 15 meters=33 feet each leg
> > For 80 meters it gets a little long=83 feet 10 inches each leg.
> > Please be aware that you get very good gain with these 
> antennas, but the
> > tradeoff is a narrowing of the radiation pattern. It 
> becomes extremely
> > important to figure out where your signal will go when you 
> transmit. At the
> > band/frequency of design you will have two lobes at right 
> angles (broadside)
> > to the wire. On bands above the design band, the lobes will 
> split and move
> > more toward the plane of the wire. (you can also operate 
> this antenna at
> > lower bands with pretty good results) I would suggest that 
> you check the
> > internet with a search for "EDZ antenna". You will find 
> quite a bit of
> > information. This antenna works great, and provides some 
> real gain, but you
> > may loose out if you orient your antenna in the wrong direction.
> > Good Luck!
>> - - - 
>> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
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