[Elecraft] QRP viability during solar cycle min?

Thu Jan 12 00:47:45 EST 2006

A related antenna with a couple dB gain is a "half-square". It's like 
half of a bobtail curtain, or two inverted L's connected at the ends of 
the horizontal parts (1/2 wave on top, 1/4 wave on the two vertical 
parts). It has a figure 8 broadside pattern, and is easily fed at one of 
the upper corners with coax.

Larry N8LP

Stephen W. Kercel wrote:

> Kevin:
>
> I think vertical dipoles are wonderful. I have used them on a heavily 
> wooded lot with great success on both 20 and 30 meters. The higher you 
> can get them off the ground the better.
>
> It is very desirable to be sure the feedline comes off reasonably 
> perpendicular to the antenna for a quarter wavelength or so.
>
> Another effective trick (especially for 80 or 40) is an inverted L fed 
> with coax at the corner. Its almost as good as a vertical dipole. 
> Again, it is very desirable to be sure the feedline comes off 
> reasonably perpendicular to both legs of the antenna for a quarter 
> wavelength or so.
>
> However, don't be too enchanted by the low angle pattern, it is also a 
> bit lossy. If you overlay your EZNEC vertical dipole elevation pattern 
> with the EZNEC broadside elevation pattern of a straight dipole at say 
> 5/8 wavelength elevation, you'll see that although the vertical 
> concentrates its energy at low angles, the actual dBi values are not 
> that much better than the horizontal.
>
> W4RNL has shown that putting a very elaborate ground screen under your 
> vertical dipole gets you virtually no advantage. The losses are 
> actually from ground losses a few thousand feet from the antenna. For 
> that reason, if you're right on a seashore, you'll get spectacular 
> results in the seaward direction. (This is the Desert Island effect.) 
> I'm located  near the coast of Maine, about 4 miles inland; the Desert 
> Island Effect does not help me much.
>
> I have both a 20 m vertical dipole (center about 20 feet off the 
> ground) and a 20 m horizontal dipole about 45 feet up. Which one does 
> better depends on propagation conditions. I have worked lots of South 
> Pacific QRP with the vertical.
>
> 73
>
> Steve
> AA4AK
>
>
> At 11:20 PM 1/11/2006, Kevin Shaw wrote:
>
>> I've been playing around with EZNEC trying to come up with a DX 
>> antenna that
>> will work at my QTH. The vertical dipole seems to have a fantastic 
>> pattern
>> for DX with low takeoff angles. I may be able to hang a vertical wire 
>> dipole
>> in one of my trees and have it nearly invisible. Anyone have 
>> experience with
>> vertical dipoles that they could share?
>>
>> Thanks,
>>
>> Kevin
>> N8IQ
>>
>>
>> -----Original Message-----
>> From: elecraft-bounces at mailman.qth.net
>> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Tony Morgan
>> Sent: Wednesday, January 11, 2006 8:39 PM
>> To: Elecraft
>> Subject: Re: [Elecraft] QRP viability during solar cycle min?
>>
>> K9QRG ON 5/12?
>> Just checking  :>)
>>
>> Tony W7GO
>> ----- Original Message -----
>> From: "Larry Makoski W2LJ" <Makos327 at worldnet.att.net>
>> To: "Darwin, Keith" <Keith.Darwin at goodrich.com>
>> Cc: <Elecraft at mailman.qth.net>
>> Sent: Wednesday, January 11, 2006 4:54 PM
>> Subject: Re: [Elecraft] QRP viability during solar cycle min?
>>
>>
>> > Darwin, Keith wrote:
>> >
>> >>K1 or K2.  Hmmm, the debate continues.  But wait, we're approaching a
>> >>sunspot min.  My antennas are pretty limited.  I have a 28 foot 
>> vertical
>> >>(fed with a tuner near the base) for 40 thru 15 and a dipole at 25 
>> feet
>> >>but that is about it.  No towers, no high wires, no yagis.
>> >>
>> >>How limiting will 5 or 10 watts (even with that Elecraft Mojo) be 
>> under
>> >>current conditions?  Are we entering into conditions where QRP with
>> >>simple antennas will become rather frustrating?  Is it K2/100 time?
>> >>
>> >>- Keith KD1E -
>> >>_______________________________________________
>> >>
>> >>
>> > Keith,
>> >
>> > Fear not fellow Elecrafter!  We QRPers laugh at the sunspot minimum!
>> > Sunspots ...... who needs 'em?
>> >
>> > I know, actually we all do. But to be serious ....  as bad as band
>> > conditions were in 2005, I managed to make at least one QRP CW QSO
>> > everyday in 2005.  If you want to check out some of who I worked (and
>> > there was a goodly bit of DX mixed in) then please check out:
>> > http://www.qsl.net/w2lj/index%20page%209.html
>> >
>> > My antennas are not much more substantial (if any) than yours.  I 
>> have a
>> > G5RV at 25 feet and a Butternut HF9V vertical which is ground 
>> mounted in
>> > the backyard.  To me it seems that if you don't spend too much time
>> > concentrating on what you think are deficiencies; but go out with the
>> > aim to just have fun, then you will be amazed at what you can 
>> accomplish!
>> >
>> > 73 de Larry W2LJ
>> > K1# 1647, K2# 4090
>> >
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