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I think one question that may have been hinted-at is if you have to keep your
DKAZ on the shorter side horizontally, can you make up the poor low band gain
by going higher on the vertical dimension?
For the EZNEC experts: If you had two 50 ft. trees 50 ft. apart and hung up
your antenna so the apex points were 46 ft. up and the base wires 6 ft. up, and
had an end to end length of 100 ft., could such a DKAZ compete with one about
1.5 times that length but half the height?
Obviously gain isn't the whole game. The null zone has to be substantially
wider than that of a regular Flag / SuperLoop and it has to hold up well across
the band without a constant need to tweak the termination via Vactrol or
something else while moving around the band.
That Powerpoint presentation referenced by Nick was interesting in that it
covered many kinds of MW antennas but didn't say much about the Beverage, once
considered the king of DX antennas.
I tried a reduced size (less than 80 ft. end to end) DKAZ here and, yes, it was
gain-dead on the lower half of the band. I wasn't even convinced that the null
zone was any better or more consistent across bandwidth than SuperLoops that
have served me well here.
I have also used a Bowtie with mixed results. See
http://www.qsl.net/wa1ion/pictures1/bowtie_s_yarmouth.gif for diagram. I
welcome comments from others who have used a similar antenna. How it compares
with DKAZ would be the most relevant topic.
DHDL is a related type:
https://dh1tw.de/double-half-delta-loop-dhdl-receiving-antenna/
My biggest pests are the NYC stations about 200 miles to the west. There is
mixed groundwave and skywave at night. The apparent arrival angles on the
higher band stations such as 1130, 1190, 1280, and 1560 move around a lot. A
proper DKAZ, an array of them, or Lankford's set-up would be just the ticket to
get that big wide back null covering that wide spray-pattern of bounce angles.
With only about 100 ft. of east-west usable yard space, that just isn't going
to happen here.
What I wind up with instead is likely to be the null-west SuperLoop, a
null-north one, and one-frequency-at-a-time phasing during live DX to throttle
down the persistent super-pests that just won't go away otherwise.
On the car roof, I used to phase a loop versus an active whip and I could get
nulls much deeper than what the loop alone gave .. but only on one frequency at
a time.
The Split Flag / Split SuperLoop designs might also be worth a look to see if
reasonable gain and directivity can be mustered in a less-than-140 ft. length.
The inconvenience of these typically requiring three tall supports may tend to
rule them out for some.
http://www.qsl.net/wa1ion/pictures1/dual_feed_split_flag.gif
http://www.qsl.net/wa1ion/pictures1/dual_feed_split_superloop_38m_long.gif
http://www.qsl.net/wa1ion/pictures1/split_superloop_201709.gif
Mark Connelly, WA1ION
South Yarmouth, MA
<<
Well here's something that's been on my mind lately, regarding
differences between superloops and the DKAZ:
It seems to be my experience so far that at night, the back and side
nulling characteristics of these antennas changes, due to sky wave vs.
ground wave, yes? Which one is more affected by those changes?
Mark
Goshen, IN
On 2018-10-24 1:42 pm, Chuck Hutton wrote:
> Mark -
>
>
> No arrogance detected here.
>
> Now back to the issue of DKAZ low band performance...?
>
>
> Chuck
>
>
> ________________________________
> From: IRCA <irca-boun...@hard-core-dx.com> on behalf of Mark Pettifor
> <m...@spacetubes.com>
> Sent: Wednesday, October 24, 2018 8:58 AM
> To: Mailing list for the International Radio Club of America
> Subject: Re: [IRCA] KAZ versus Pennant/Flag
>
>
> Apologies, Chuck, and to the rest here. In looking back at my post, I
> realize I could have said things a lot less arrogantly and put-offish.
> That's how I sounded to myself anyway after re-reading what I posted.
>
> 73,
> Mark
>
> On 2018-10-24 1:57 am, Chuck Hutton wrote:
>> Mark -
>>
>>
>> I suppose we all agree that the DKAZ has nailed some great catches.
>>
>> My goal was to point out a shortcoming, not to say that it can't hear
>> DX a la Colombia / Venezuela / Nicaragua.
>>
>>
>> Chuck
>>
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