Pete Soper wrote:
>
> Hi Jerry,
>
> > proto-type. There isn't even a PRICE available from MFJ. Makes ya wonder
> > doesn't it???????
>
> This is common practice in the computer industry and led to the term
> "vaporware". Very sad to see this has infected amateur radio. On the other
> hand, it would be nice to see another practice that is common with computers
> and that's objective "knock their heads together" benchmark comparison of
> competing products. This doesn't seem possible for the amateur mags for
> various reasons.
>
> Regards,
> Pete
> KS4XG
Hi Pete -
Not sure that this is a "standard" industry practice as yet. I
am
somewhat surprised that someone from CQ Magazine hasn't seen the post
and made a comment abt it! When I called MFJ, the gal who answered my
call more or less said "Huh, MFJ-414????" And then put me on hold for
abt 5 minutes while she tracked it down. I then ended up reading her the
part of the article pertaining to the 414. She couldn't figure out where
they even got the thing from! It was "supposed" to only exist in
in-house prototype only!!!!!!!! Ah well, makes life kinda interesting
doesn't it!?!?!?!
-73-
Jerry
>From w2vjn@rosenet.net (George Cutsogeorge) Mon Aug 26 02:57:34 1996
From: w2vjn@rosenet.net (George Cutsogeorge) (George Cutsogeorge)
Subject: Vertical Phased Array
Message-ID: <M.082596.185734.92@ppp061.rosenet.net>
The stack match is a good way to feed two antennas that have little or no
mutual coupling. It connects the two antennas in parallel and drives the
combination through a step down transformer. In this case the antenna feed
impedances are matched to 50 ohms and they will get equal currents if connected
in parallel.
This is not the case for two vertical antennas that are close spaced. The feed
impedances are different due to mutual coupling. The stack match will not
drive them with equal currents so the gain and F/B will not be as expected.
ON4UN does a good job of explaining how to drive mutually coupled antennas and
is recommended reading.
----
George Cutsogeorge, W2VJN
Umpqua, OR.
http://www.qth.com/topten
>From 0002104829@mcimail.com (RONALD KLEIN) Sun Aug 25 22:49:00 1996
From: 0002104829@mcimail.com (RONALD KLEIN) (RONALD KLEIN)
Subject: Vetical phased arrays
Message-ID: <50960825214905/0002104829DF4EM@MCIMAIL.COM>
-- [ From: Ron Klein * EMC.Ver #2.3 ] --
-------- REPLY, Original message follows --------
From: Donald Russell \ Internet: (drussell@knox.net)
From: Donald Russell \ Internet: (drussell@knox.net)
To: CQ Contest - POSTS \ Internet: (cq-contest@tgv.com)
Subject: Vetical phased arrays
Fellow Contesters:
I am considering a Vertical phased array to replace my existing Butternut
HF2V single element vertical. This Vertical by the way, does an excellant job
on 40 meters, but not so good on 80. I was going to tear this present system
down and go strictly with 2 40 meter elements with no traps. Fed in phase and
out of phase for the common figure eight pattern. This would allow me to put a
better signal into Europe and NE USA, California, and Southern USA on 40
meters. I am more interested in the domestic contests than I am in DX, but
then.....
I got to thinking. It would be nice to keep the HF2V, add another
and have a
2 element phased array on 80/40. I think the extra gain on 80 meters
would maybe bring the gain up to that of a dipole, and being able to null
out the sides would aid the battle of QRM. I could easily feed this
multiband system in phase just by cutting the coax to equal lengths and
maybe using the WX0B stack-match (or an antenna tuner). I haven't figure
out a simple way to feed this system out of phase though. Seems like you
would have seperate phasing lines and switch them in with relays.
Another
way of doing this would be to use a 3 element triangular system such as W9XT's
in the March/April 1993 issue of NCJ. Feed two elements in phase at all times,
switching between the three to obtain the direction desired. Then go with the
stack-match totally. No worry about feeding the antennaes out of phase. Of
course this would take an extra element and may not be XYL approved. Then
again, pretty well low profile stuff. Any suggestions or comments on either of
these systems would be appreciated as I have found no documentation of an 80/40
mtr vertical array being tried before.
73, Don WA8YRS drussell@knox.net
-------- REPLY, End of original message --------
Well, it's time to say something instead of just being a "lurker" on the
reflector.
Don, I have been using for 5 years now a pair of Hytower verticals as a 2
element phased array.
There is nothing exotic required to achieve relatively good performance. They
are positioned
1/4 wave apart at 3800, with switchable phasing lines used for 1/4 phasing. In
my case they are
oriented on a line 45 degrees east of north which is optimum for Europe and the
south pacific.
The resulting cardiod pattern is broad enough that it covers the rest of the
world as well. I do see
20 to 25 db nulls on the back of the axis. While it won't touch K0RFs (5 miles
from me) 3
element KLM he has at 100 ft on top of his hill, it does significantly better
than the average
dipole or single vertical. I easily work Europe long-path at sunrise, for
example. It performs well
in contest and pileup situations. I do have a half-mile of radials under them,
which is critical to
their performance of course.
I found the ON4UN "Low Band DXing" book to be a very useful source of
information when I was
planning my installation.
This combination also is "close" to being a 1/2 wave spaced, 1/2 wave phased
arrangement on
40 as well. I have my remote switching configured to support that end-
fire/broad-side pattern on
40. It seems to do relatively well. Since installing my PRO-67B 4 years ago,
with it's 2 elements
on 40, I occasionally do a comparison between the Mosley and the 2 element
Hytower array. On
occasion, the verticals win.
The Hytowers are an efficient, broadband design. I'm not sure how you would do
with trapped
verticals such as the butternut, but it would not cost much money to find out.
For what it's worth.
73, Ron - W0OSK
>From rdidonna@tacarlson.com (Rich DiDonna) Sun Aug 25 23:00:27 1996
From: rdidonna@tacarlson.com (Rich DiDonna) (Rich DiDonna)
Subject: Everybody really is 599!
Message-ID: <Pine.LNX.3.91.960825175900.28116A-100000@gateway.tacarlson.com>
I was doing some thinking - a lot of the time the noise level is so damm
high that every signal has got to be at least s-9 in order to be audible.
I'm sure there are a few 160 types out there who do not use beverages -
therefore their one vertical antenna will pick up noise/signals
significantly over the 9 level
Rich KI6ZH
On Sat, 24 Aug 1996, Lee Hiers AA4GA wrote:
> Readability - If I copied you, you must be perfectly readable, I'll
> give it a "5"
>
> Signal Strength - That RF travelled all the way from your qth to mine
> - on 160? - must be extremely strong, I'll give it a "9"
>
> Tone - Sounds good to me, I'll give it a "9"
>
> See, everybody really is 599...what's the problem?
>
>
> The best contest in the world (SS) doesn't use RST...why set sights
> any lower?
>
>
> I'm off to Montana for a week's worth of trout fishing...
>
> See Y'all!
>
>
> --
> Lee Hiers, AA4GA
> Cornelia, GA
> aa4ga@contesting.com
>
>
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