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w6qhs - yagi failures

Subject: w6qhs - yagi failures
From: ERIC.L.SCACE@adn.sprint.com (ERIC.L.SCACE@adn.sprint.com)
Date: Mon Jun 13 12:33:30 1994
Hi Dave --

   Sorry, lost the original message with your internet address...

My experience has been with KLM KT34XA:

1. bent elements from ice loading:
   cause: weak point in element design is one foot from butt of element,
          where an inner strengthening tube (I think it is 3/4") section
          stops.
   fix: replace inner section with longer section; I used 6' sections that
        I had lying around.

2. boom failure at boom-mast plate, front half
   cause: massive wind loading after > 1" radial ice load.  wind speeds above
          60 mph.  boom collapsed sideways, ripped off.
   fix: probably requires trusses with a sideways component to them, rather
        than a simple overhead truss

in the same storm :

3. elements fell off:
   cause: hose clamps which fasten element mounting backet around the boom
          snapped thru the bands due to horizontal windload on iced element.
   fix: none possible with current design.

and finally:

4. strap which taps T-match and the element end loading section to the main
   tube of the element slipped off.
   cause:  collision of element with the ground
   solution:  install antenna in free space

-- Eric K3NA

p.s.: oh yeah -- their turnbuckles for the overhead guy will rust.  replace
      with galvanized units.

The KT34XA is also not wind-balanced.  Move antenna at least a foot to rear
and add counterbalancing weight inside boom.




>From es@mvuss.att.com (Edward S Parsons +1 508 960 6722)  Mon Jun 13 16:55:00 
>1994
From: es@mvuss.att.com (Edward S Parsons +1 508 960 6722) (Edward S Parsons +1 
508 960 6722)
Subject: VHF Scores, Issue 2
Message-ID: <9406131557.AA01916@ig1.att.att.com>

Jun 1994 ARRL VHF Contest Early Scores, Issue 2
--------------------------------------------------
Please send any additional scores. K1TR @ K1XX or Internet: es@mvuss.att.com
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
S/O:

BAND      WA2TEO    K1RZ     KA1ZE    K9MK
------    -------   ------   -------  -------  -----    -----   -----    ------
50MHz     202/55    162/53   62/23    214/96
144       344/41    281/44   415/41   166/34
220       82/29     65/26    79/28    6/3
432       124/35    103/30   134/34   67/22
903       21/15     17/13    16/11    2/2
1.2       31/14     34/16    32/13    13/7
2.3       5/3                5/3
3.4                          3/2
------------------------------------------------------------------------------
TOTAL     809/192   662/182  746/155  468/164
          216k      169k     167k     94k

BAND      N1DPM     K3ZO     K1ZZ     W2IOG/3  KO0U/4   KC5BQS    
------    -------   ------   -------  -------  -----    -----   -----    ------
50MHz     43/22     194/69   106/24            45/19    3/2
144       98/27     273/42   175/24   132/38   93/25    14/7
220       52/21              3/2      38/21             
432       69/23              55/17    33/17    47/17    5/2
903       11/8                                 4/3
1.2       28/12              2/2      11/8     10/4     2/1
2.3       8/5
3.4       4/3
------------------------------------------------------------------------------
TOTAL     313/121   467/111  341/69   214/84   195/65   28/15
          66k       52k      28k      26k      17k      675

QRP-Portable:

BAND      KH6CP/1
------    -------   ------   -------  -------  -----    -----   -----
50MHz     47/15
144       111/20
220       54/17
432       71/15
903       14/8
1.2GHz    22/9
2.3       5/4
3.4       4/3
5.6       6/4
10        3/3
-----------------------------------------------------------------------
TOTAL     337/98
          57k

Rover:

BAND      N5RZ(+K5MR) NG0X     NJ2L
------    -------     ------   -------  -------  -----    -----   -----    
------
50MHz     206/120     66/34    19/12
144       168/89      80/38    16/14
220                            15/12
432       64/42       34/21    12/9
903                            4/4
1.2       22/17                5/4
------------------------------------------------------------------------------
TOTAL     460/268     214/93   71/55
          152k        20k      6.4k

Limited/Multioperator:

BAND      K1TR/3    K3MQH    W3EP/4   K3UA     W5KFT    KB5KYJ  WW1M/9 WD0T
------    -------   ------   -------  -------  -----    -----   -----  -----
50MHz     440/86    383/78   480/135  378/98   472/194  148/71  48/27  29/23
144       756/50    707/57   280/55   571/64   126/28   54/22   57/21
220       140/35    142/36   95/44    82/36                     21/13
432       262/38    242/41   105/39   93/37    41/17    13/8    16/6
1.2                                            16/10
----------------------------------------------------------------------------
TOTAL     1598/210  1474/212 960/273  1124/235 655/249  215/101 142/67 29/23
          418k      394k     316k     305k     181k     23k     12k    667

Multioperator/Unlimited:

BAND      W2SZ      N2WK     W3ZZ     W4IY     W0UC     W3XO/5
------    -------   ------   -------  -------  -----    -----   -----
50MHz     395/70    293/92   380/106  307/83   214/100  311/146
144       594/52    428/64   433/57   358/59   273/66   71/19
220       159/33    180/47   84/33    59/26    55/30    3/3
432       284/40    221/47   171/39   143/32   91/35    21/12
903       58/21     77/32    22/16    14/8     3/3      3/2
1.2GHz    91/24     86/29    78/18    30/13    21/13    5/3
2.3       53/17     46/23                      1/1
3.4       41/10     17/14
5.6       30/7      9/7
10        41/7      16/3              5/1
24        19/7
144G      1/1
-----------------------------------------------------------------------
TOTAL     1766/289  1379/360 1153/273 916/222  658/248  414/185
          885k      860k     426k     271k     212k     84k

>From eric%modular.UUCP@cs.arizona.edu (Eric Gustafson)  Mon Jun 13 16:46:39 
>1994
From: eric%modular.UUCP@cs.arizona.edu (Eric Gustafson) (Eric Gustafson)
Subject: Antenna Question
Message-ID: <9406131546.AA25671@modular>

Randy,

I haven't done any modeling to confirm the claim.  As of right now I'm
highly skeptical.  But...  _IF_ the addition of a parallel unconnected wire
had the effect of raising the radiation resistance significantly, then the
losses in the ground connection (usually between a 12 and 25 ohm connection
for a single ground rod) would become a much lower fraction of the total
resistance in the circuit and the effeciency would be increased.  A single
element 1/4 wave vertical has a radiation resistance of about 36 ohms.  so
with a (lucky) 12 ohm ground rod, it would be very close to a 50 ohm system
at resonance (and the efficiency would be close to 75% to begin with).  I
guess I'll have to look at the article to see what is actually being
proposed.  To have only a 20 percent efficiency, would require the antenna
to have only 3 ohms of radiation resistance (again assuming our lucky 12
ohm ground rod).

An efficiency increase (as I read this statement) from 20 to 60 percent
means to me:

1.  Originally the efficiency was 20 percent

2.  Now it is 60 percent

3.  I can now (with the same power input to the system) expect my signal to
    be almost 5 dB (about 1 S-unit) louder than it was when the efficiency
    was 20 percent.

73  Eric  N7CL

------------------------------------------------------------------------------
Eric Gustafson  N7CL                  | The mountains are high and the Emperor
6730 S. Old Spanish Trail             | is far away.
Tucson, AZ 85747                      |
INTERNET: modular!eric@cs.arizona.edu | You can't work 'em
     CI$: 71750,2133                  | if you can't hear 'em.
------------------------------------------------------------------------------



>From Jim Reisert AD1C  13-Jun-1994 1213 <reisert@wrksys.enet.dec.com>  Mon Jun 
>13 17:46:06 1994
From: Jim Reisert AD1C  13-Jun-1994 1213 <reisert@wrksys.enet.dec.com> (Jim 
Reisert AD1C 13-Jun-1994 1213)
Subject: Recent VHF/UHF ARRL 'test (de N4MM)
Message-ID: <9406131646.AA00381@us4rmc.pko.dec.com>

[Forwarded from YCCC PacketCluster]


I have been receiving comments about some of the poor operating practices
in the recent ARRL June VHF Contest.  I participated in the contest some,
but due to other duties I was not on that much.  I heard somethings that
were not in the best interest of the contest spirt and carryovers from
HF contests.  I received a rash of phone calls back in January when the
ARRL VHF/UHF SS was running.  Most of these were due to hogging FM
channels, endlessly.

In order to get action and more awareness of these situations, please write
the CAC, and copy your ARRL Director.  The more people who take the time
to do this, the quicker things will happen.  If only one or two write,
the problem will not receive the attention that it should.  For example:
If only one or two write, chances for any quick positive action are slim,
however if many write, then things will move faster and be taken more
seriously.  Ten letters is better than one, 100 letters is better than 10.

73, John, N4MM

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