Grounding again

Tue Aug 22 15:17:15 EDT 1995

Hi Bob...
Using the well casing as a ground/counterpoise has a couple of drawbacks...

1st.... Ground systems want to be shallow and spread over considerable square
footage to give the current surge adequate surface area for dissipation..
Current flow in a lightning strike is a surface/skin phenomena, with a surge
rise time of about 1 microsecond... A DEEP ground (hundreds of feet) is no
better than a rod in the ground just deep enough to reach moist/conductive
material (3 to 8 feet)...A well casing is no more effective than a ground rod
 - and needs radials to be effective as a counterpoise...Once you have the
radials you don't need the ground rod :)  ...  or the well casing!...

2nd... Well casings, used as a lightning ground rod, blow out the windings on
the pump motor with depressing regularity...  :(    
Most new wells have plastic casings!!!

Cheers  ...  Denny

>From n6ig at netcom.com (Jim Pratt)  Tue Aug 22 19:33:26 1995
From: n6ig at netcom.com (Jim Pratt) (Jim Pratt)
Date: Tue, 22 Aug 1995 11:33:26 -0700 (PDT)
Subject: S-Meters, Piece Corrections
Message-ID: <199508221833.LAA04189 at netcom14.netcom.com>

Cheap and unfair shot??  My goodness, how one's true intent can easily be 
misunderstood...
Actually, I was paying Fred a compliment of the highest order.  My 
memories of him at Visalia CW-copying contests are that his ears are 
wonderful;  he has an uncanny ability to pull stuff out of a pileup with 
the greatest of ease.  Hence the reference to him using wide filters...

Now, on with the show;  gee, I can't wait for fall, we sure need some 
contests to ease all this pent-up frustration!

73, N6IG

>From Douglas S. Zwiebel" <0006489207 at mcimail.com  Tue Aug 22 19:35:00 1995
From: Douglas S. Zwiebel" <0006489207 at mcimail.com (Douglas S. Zwiebel)
Date: Tue, 22 Aug 95 13:35 EST
Subject: contest writeup; CQ
Message-ID: <35950822183553/0006489207PK3EM at MCIMAIL.COM>

Wow...let's hear it for those great COLOR pictures in the CQWW 'test
writeup.  What a NICE change!!!!  AR...was this your's?  FB OM!
de Doug  KR2Q at mcimail.com

>From n4zr at ix.netcom.com (Pete Smith)  Tue Aug 22 19:39:15 1995
From: n4zr at ix.netcom.com (Pete Smith) (Pete Smith)
Date: Tue, 22 Aug 1995 11:39:15 -0700
Subject: Modeling and reality
Message-ID: <199508221839.LAA00982 at ix8.ix.netcom.com>

  Let me stir the pot a bit concerning antennas and modeling.

  Just the other day, I was talking to a pretty well-known antenna designer
  (who shall remain nameless).  I mentioned that I had opted for a high (100
  ft.) single-tribander rather than a stack on a significantly shorter tower
  (ca. 70/40 ft), on advice that the high antenna would be better than the
  lower stack for DX contest operating for the next several years.  He opined
  that, contrariwise, on HF a stack would almost always outperform the high
  single antenna, and that models severely underestimate the gain to be
  realized by stacking.  Experience showed, he said, that HF stacking gains on
  the order of 6-12 dB are achieved in the real world, while modeling
  indicates a maximum of 3dB.  He went on to say that he had asked around, and
  some antenna gurus said that other phenomena were at work in the case of HF
  stacks, having to do with ground interactions and increased effective
  aperture.  Do any of you stack owners or antenna folk out there want to
comment?

  On another tangent, I had read (and maybe misunderstood) what Dave Leeson
  had to say in his book about smoothness in the Fresnel zone, and had assumed
  that minor irregularities (say +/- 10 ft. at 14 MHz) in the altitude of the
  surface in that zone should have little effect on the antenna pattern.  My
  foreground profile to Europe has the base of the antenna at 550 ft.ASL, with
  the terrain rising to 560 ft.ASL at 1000 ft. from the base, then dead flat
  out to 15000 ft. or more.   To my surprise, though, when I run YTAD for a
  single antenna at 100 ft. aboce ground, that 1/100 slope is responsible for
  a 3 dB. notch in the modeled vertical pattern at 5 degrees elevation.  Can
  this be right?

  73, Pete Smith N4ZR
  n4zr at ix.netcom.com  *** note new e-mail address ***

  No, no, no, that's 59 WEST Virginia.

73, Pete Smith N4ZR
n4zr at ix.netcom.com  *** note new e-mail address ***

No, no, no, that's 59 WEST Virginia.

>From M. Curran" <curran at howard.genetics.utah.edu  Tue Aug 22 13:59:17 1995
From: M. Curran" <curran at howard.genetics.utah.edu (M. Curran)
Date: Tue, 22 Aug 1995 06:59:17 -0600 (MDT)
Subject: KI7WX NAQP Score/Comments
Message-ID: <Pine.SOL.3.91.950822063630.20304B-100000 at howard>

Call 	KI7WX
Sec  	Utah
Name	Mark

Single Op distracted, 1 radio

Equipment:  FT-1000, 10,15,20M Yagis (40ft), 40M vert, 
		     80M loop, 160M inv-l

Score = 470 Q's by 103 M's = 48,410 pts

Comments:  Lots of fun driving Alan's station again.  No 10/15
prop here either and the noise on 80M really hurt.  Hoped for
more 160M activity.  Worked everyone we asked to move there,
picking up CO, CA, WA, OR and ID mults.  Missed ME, KP2, and
a couple provinces.  Intended to use "DOC" rather than Mark to
celebrate recent completion of Ph.D, but arrived late and forgot
about it.  Always fun to work the reflectorites.  CU in the sprint...

Cheers,

Mark

Mark E. Curran, Ph.D.	KI7WX	   
Curran at Howard.Genetics.Utah.Edu

LA op: "KI7WX, that's a mouthful!!"  
Me:    "Try it for a whole contest .... .."

>From n4zr at ix.netcom.com (Pete Smith)  Tue Aug 22 20:37:27 1995
From: n4zr at ix.netcom.com (Pete Smith) (Pete Smith)
Date: Tue, 22 Aug 1995 12:37:27 -0700
Subject: Re New Radios
Message-ID: <199508221937.MAA09535 at ix8.ix.netcom.com>

K8DO wrote

>Hey Randy....
>
>Is your shack ALWAYS that neat?  And, how about telling us what each of those
>little switch boxes do....   :)
>
And is anybody THAT young?

73, Pete Smith N4ZR
n4zr at ix.netcom.com  *** note new e-mail address ***

No, no, no, that's 59 WEST Virginia.

>From Dan Norman KJ1N <dnorman at gleneagle.scd.ucar.edu>  Tue Aug 22 20:55:52 1995
From: Dan Norman KJ1N <dnorman at gleneagle.scd.ucar.edu> (Dan Norman KJ1N)
Date: Tue, 22 Aug 1995 13:55:52 -0600 (MDT)
Subject: Integrated Rig and PC (was DSP Radios)
Message-ID: <Pine.SUN.3.91.950822133423.398A-100000 at gleneagle.scd.ucar.edu>

On Tue, 22 Aug 1995, Steve Runyon WQ5G 512-838-7008 wrote:
> 
> I guess instead of knobs, we'd have to use the mouse to select the 
> functions, tune the rig, etc ... well, OK, I could get used to that. 
> I'd definitely want the optional heavy-duty computer power supply to 
> get the full 100 Watts output - I need it to drive the external 
> linear, plus I don't want to be QRP all of the time! I could even go for  
> the optional fiber-optic interface to allow placing the amp at the 
> base of the tower and get rid of the feed-line losses. (Those 
> searching for the last fraction of a dB could even mount the 
> PA right below the beam, as was suggested yesterday.)
> 
> Of course, it'd come with a built in packet controller, and the 
> supplied logging program would interface directly with the 
> 'ham card' via the system bus instead of this archaic RS-232 
> stuff... 

Don't forget about the CD rom that would enable the PC to run the 'test
also!  We could all hit F1 Saturday at 0000Z and never say one word during
the contest...now this is a feature my wife would go for ;-)

I know...sick humor.  Need to let the imagination run wild occasionally.

'73 Dan KJ1N/0

>From David & Barbara Leeson <0005543629 at mcimail.com>  Tue Aug 22 21:11:00 1995
From: David & Barbara Leeson <0005543629 at mcimail.com> (David & Barbara Leeson)
Date: Tue, 22 Aug 95 15:11 EST
Subject: Modelling & reality
Message-ID: <30950822201103/0005543629NA3EM at MCIMAIL.COM>

Pete, N4ZR, asks about the effect of small surface irregularities on antenna
pattern.  The Rayleigh limit applies to bumps for which all dimensions are
a fraction of a wavelength (not just the height), so a long inclined
foreground would be likely to have some effect.

Second, note that terrain analysis programs are currently 2-dimensional
(the 3-D problem is really a bear).  This may have the effect of over-
emphasizing distant terrain features as compared to 3-D reality (although
probably not in the case of near-flat terrain).

In any event, the N6BV/K6STI efforts are a huge step in the right direction,
since only a few years ago there were only a few attempts at terrain 
reflection analysis, and these took big iron computers.  There is a body
of work on reflections from planetary surfaces of radar signals, although
in that case the game is to deduce the surface roughness and all from the
the time and frequency artifacts of the reflected signal.

Last, an assumption is often made that the reflection from nearby ground is
modelled as a plane wave reflection, but the actual physical case is
spherical waves.  Luckily, however, nature is pretty continuous; there is
a very thorough book on this issue by R. W. P. King, called Transverse
Electromagnetic Waves (I'm still on page 5).

Bottom line: modelling is much more knowable than most experiments, and
can be a great guide to, but is not identical to, reality.

73 de Dave, W6QHS