[Top] [All Lists]

[TowerTalk] yagi comments

To: <>
Subject: [TowerTalk] yagi comments
From: (
Date: Thu, 12 Jun 1997 11:06:58 -0400 (EDT)
In a message dated 97-06-12 03:33:40 EDT, (Frank T.
Brady) writes:

> The results boiled down to Force 12 and M2 as the "winning" candidates for
>  the 20m monobander.  There seems to be sharp disagreement about which of
>  those two is the best.
>  M2 recommends their biggest ($750) 20m monobander (4 elements is enough,
>  they say) and the Force 12 20m monobanders listed are 5 and 6 elements
>  ($865 and $1150 respectively).  The prices seem to be comparable, but
>  was SHARP disagreement on whether or not the Force 12 construction is as
>  sturdy as the M2.

     Four elements are "ENOUGH"? Since when? Not in any competitive or big
gun wannabe station I've ever seen. 

    As far as the mechanical design considerations, there are two schools of
thought. The first is the "make them like a battleship"; this is the Telrex
approach and has been the traditional way to design them. In other words,
make them big and heavy. That way, in case of a big wind, the sturdy parts
will be able to survive the wind forces. 

    The second school of thought is to use currently available mechanical
stress modeling software to find out where the stresses are and make them
strong while reducing the stresses on other parts by using complementary
techniques. This is what Force 12 does. They have found that tapered booms
and aggressively tapered elements allow them to use 'smaller' materials that
reduce the overall wind load and weight of the antenna. The philosophy is to
"bend like a willow and not break like an oak". And you know what? It works.
An added benefit is that it reduces the wind load and stresses on your tower,
mast and rotator. 
>  I guess the only important issues are whether or not the two are
>  in gain and durability - if so, I can flip a coin or close my eyes and jab
>  out a selection.  If anyone has any further input on this, I'm all ears!
      Mike, K6MYC, of M2 and Tom, N6BT, of Force 12 are both recognized as
excellent antenna designers but Mike's groundbreaking innovations on HF were
back in the 70's whereas Tom is developing new unique designs now. 

    Mike has effectively retired from M2 and lives in Hawaii so if you call
them you get ahold of his son, Matt. Matt's a nice guy but he is NO leading
edge antenna designer or competitive station builder. He's a Technician
that's probably never worked a contest or a DX pileup. 

    OTOH, when you call Force 12 and talk to Tom, you get not only one of the
best antenna minds around but also someone who just got back from a
DX-pediton to Burma as well as setting up and operating a MM contest station
from the Caribbean during this past contest season. Who's opinion is more

     Yes, I am a Force 12 dealer and an M2 dealer.

73,  Steve  K7LXC

    TOWER TECH -- professional tower supplies for amateurs

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>