[TowerTalk] Klm 40m-1

[Jim Thomson]

Date: Thu, 28 Jan 2016 14:11:21 +0000 (UTC)
From: Rod Greene <w7zrc at yahoo.com>
To: Arnie Pfingst <arnie123 at hotmail.com>, "towertalk at contesting.com"
<towertalk at contesting.com>
Subject: Re: [TowerTalk] Klm 40m-1


Arnie,
I have one of the old KLM 40m-1 antennas and have used it for years. So far it has served me well. They do not normally need a truss support. I don't know what the wind specs are for your area of the country, but for the northwest where I am located, no truss is needed, nor called for in the documentation. 

I don't think the antenna is anything to "write home about" but it is a very good antenna for a shortened 40. And it handles and turns easily on a tower. I have no idea how it would compare to a CushCraft.
73, Rod/w7zrc

##  My problem with the CC 40m ants..like their  XM-240 is... they use like 68 turns of 12 ga magnet wire, wound butt tight on a 3/4 inch fiberglass form. 
Loss in EACH  coil is aprx   8.23 ohms.   Q is like aprx 81.   Any loading scheme would be better than this..and easily fixable.   3/16  or  1/4 inch  al or cu tubing would be ideal.

##  The LL rods used on the klm-40 could also be easily replaced with hb  tubing coils.    Then you would have a loss of way under  1 ohm..and a Q of 750 –1300  on either the klm or the CC ant. 
##  a simple dacron truss  would ensure minimal  sag with any snow or ice load.  Just make sure any truss is high enough above the 40m ele. 

Jim   VE7RF