[TowerTalk] Lightning Bolt feed

CubexCo at aol.com CubexCo at aol.com
Thu Apr 20 10:17:43 EDT 2006

In a message dated 4/20/2006 1:41:29 AM Eastern Standard Time, 
towertalk-request at contesting.com writes:
Message: 2
Date: Wed, 19 Apr 2006 23:02:40 -0600
From: "denis coolican" <coolican at telus.net>
Subject: [TowerTalk] Lightning Bolt Quad
To: <towertalk at contesting.com>
Message-ID: <014f01c66437$a6be3520$8e00a8c0 at mycomputer>
Content-Type: text/plain;    charset="iso-8859-1"

This four element Lightning Bolt Quad covers 20, 17, 15, 12 and 10 meters. It 
is fed by a common balum. (one input PL259 and 5 output pairs of conductors)

Does anyone know what type of balum this is and what would be the replacement 
for it?

I imagine the driven elements for each band has an impedance of about 80 to 
100 ohms.  The feed into the balum is 50 ohms.

If a person provides a 2:1 balum for each feed, would the unused balums be 
terminated in 50 ohms or left open?

Any more thoughts on this antenna?
The device feeding the antenna is a BALanced to UN balanced transformer 
(BALUN) and usually the Lightning Bolt device had a HI and LO terminal with a 
common terminal.  The higher frequencies on the HI terminal and lower on the LOW 
terminal.    HI terminal nominally would be about 100 ohms plus, and the lower 
50 ohms.  
I would recommend individual feeds for each band, and a remote switch.  Use 
odd quarterwave 75 ohm cable to make impedance transformers.

Norm W4QN

More information about the TowerTalk mailing list