NA SOFTWARE/EDITING

Tue Aug 30 15:35:59 EDT 1994

I worked a 9y4 during the NAQP.  It counts as a qso but not as a multiplier.
During the contest I force fed the State field with TI so it would accept
the QSO.  This has inflated my electronic score by one multiplier.

I have tried to edit the field to a blank and several other characters so
it will not count as an extra multiplier, but can't get it to accept during
the conversion from an ASCII file to a QSO file.

I'm running version 5.14 I think.  Its been a while since I bought it.

Any ideas on how to edit the file, I'd like to send the logs via disk, but
I won't be able to until I get this resolved.

73,
Rich - WB5M - RTHORNE at VNET.IBM.COM

>From Steve Fraasch <sfraasch at ATK.COM>  Tue Aug 30 22:00:00 1994
From: Steve Fraasch <sfraasch at ATK.COM> (Steve Fraasch)
Date: Tue, 30 Aug 94 14:00:00 PDT
Subject: PIN Diode (Microsemi) Correct Ph Number
Message-ID: <2E639DF2 at msm.ATK.COM>

Re: PIN Designer's Handbook:

>Tnx for phone number.  I have tried the posted number twice and they
>don't know any Bill Dougherty.  If you would, please confirm the above
>number.

OOOOOPS:

The correct number is:

617-926-0404

The first number I gave is for Unitrode, which no longer handles PINs, 
sorry.

Steve Fraasch

sfraasch at atk.com

>From Steve Fraasch <sfraasch at ATK.COM>  Tue Aug 30 23:24:00 1994
From: Steve Fraasch <sfraasch at ATK.COM> (Steve Fraasch)
Date: Tue, 30 Aug 94 15:24:00 PDT
Subject: (again) Elevated Radials
Message-ID: <2E63B1C8 at msm.ATK.COM>

Before the discussion goes farther regarding accuracy of computer 
simulation, other's verification, antennas are black magic, etc., I want to 
modify my original statements regarding 4 elevated radials.

I've been running numerous cases over the past week on NEC 2, to re-confirm 
what I found last fall.  I am almost done with the results (some are here). 
 In fact, the previous comment regarding 4 elevated radials not working well 
applied to an array, and not single verticals.  The array vs. single results 
are in fact different on NEC2, probably due to the fact there's no practical 
method of arranging elevated radials in an array such that they don't couple 
and de-tune themselves from quarter wave stubs.

1.)  4 elevated, quarter wave resonant radials DO APPEAR to provide the 
lowest real value of drive impedance (Re[Zin]), and highest gain according 
to NEC2:

Ground:  Er = 15, Conductivity: 5 mMhos/m  (average ground):
Test Freq: 3.79 Mhz
Vertical base height: 10'
Monopole Length: lamda/4 or 64' 10.5"  (total height: 74' 10.5")
Tower Cross Section:  Rohn 25 (Circumference of 36" made equivalent to 5.73" 
radius for simplicity)

# Rads       Length                                   Zin             Gain @ 
10 deg Elevation        Peak Gain, Elevation Angle
4             lambda/4 (64' 10.5")          34.5 + 5.62j        -1.04 dB 
                                                 .73 dB @ 22.5 deg
8             lambda/4                              35.5+ 8.02j        -1.16 
dB                                                   .61 dB @ 22 deg
12           lambda/4                              36.0+ 9.67j        -1.22 
dB                                                  .55 dB  @ 22 deg
16           lambda/4                              36.3+ 10.7j        -1.25 
dB                                                  .52 dB  @ 22 deg

Clearly, according to NEC2 for the conditions given, the 4 elevated case is 
superior to the 16 case.  These results are consistent with Christman's 
findings.  Also, the trend is opposite I reported last (I considered a much 
longer radial, which did not present a quarter-wave stub characteristic).

If someone wants the details, I will send them, but the following is a 
summary of recent NEC2 findings:

2.)  Using 8, not 16, elevated 3/8 lambda radials provide slightly more gain 
(.80 vs .73 dB) than 4 elevated quarter wave radials (stubs), with a 
slightly lower real value of zin (33.3 + 61.8j).  Note the increased 
reactance, which is undesirable (reduced BW).

3.)  Elevated halfwave radials were indeed ineffective, again, most likely 
due to the radial acting as a halfwave stub, transfering the far-end open to 
the tower.

4.)  Now, the interesting part:  In a 4 square array, where 4 elevated 
radials interconnect each tower along the side, and extend lamda/4 outward:
                                                    |      |
                                             ---- o---o----
                                                    |      |
                                             ---- o---o----
                                                    |      |

using lambda/4 elements, spaced .26636 lambda apart (spacing where sidelobe 
level = backlobe level), the same SINGLE elevated vertical had less gain 
(-.38 vs. .73 dB) and a higher real drive impedance (38.6+11.6j vs. 
34.5+5.62j) than the single lambda/4 radiator over 4 elevated lambda/4 
radials.

Moreover, when the 4 radials were rotated about each tower 45 degrees (such 
that the radials would align on the diagonals), the gain dropped from -.38 
to -1.89 dB.  The drive impedance rose from: 38.6 + 11.6j, to 47.0 + 18.0j 
(The radials were isolated from each other in the center).

Clearly, a single monopole over an array of 4 elevated radials is very 
sensitive not only to length but radial position (according to NEC2), as 
well.  Personally, I don't like this, and would like to have something less 
sensitive.

5.)  I will continue to run cases.  My interest is my own set-up, where I am 
installing a 75m 4 square in a swamp with 4' high water (pseudo-elevated).

6.) Hopefully, the following indemnifies Al Christman, and I wished now I 
had re-checked my findings last week before sounding off.   Still, I have a 
nagging thought about 4 elevated radials.  Even NEC shows that the lack of a 
truly resonant system of 4 quarter wave radials in an array (due to 
conforming to a spacing which negates using isolated lambda/4 stubs) reduces 
performance.  As far as the on-the-air results show, the system I listened 
to certainly sounded dead.  As trivial as this discussion may seem to some 
(and I'm about to agree), a high performance ground plane for an array (w/ 
minimal work) is yet to be defined.  If anyone knows of a journal article on 
same, I would like to read it.  The 1937 Brown article in IRE is the last 
full-blown radial study I know of.

All disclaimers are in effect, including my ability to read data from paper. 
 Al's Christman's right (at least on NEC2, with a single monopole); Humble 
pie eaten gladly,

Steve Fraasch, K0SF

sfraasch at atk.com