[TenTec] [Ten Tec] Bazooka antenna.. More than you wanted to know!

[Dr. Gerald N. Johnson]

On Wed, 2008-06-04 at 17:34 -0500, GARY HUBER wrote:
> Jerry,
> 
> Does that include strong electrical noise? I thought the Double Bazooka 
> design was low impedance on receive for the band it was built for while high 
> impedance for all other frequencies. There are other ways to achieve similar 
> results but I used this antenna on 40 M when I could not use a regular 
> dipole or vertical due to high line noise.
> 
> 
> 
> Best regards,
> Gary - AB9M
> CSM(r) G.L.Huber
> 9679 Heron Bay Road
> Bloomington, Illinois 61704
> (309)662-0604
> www.csm-gh.com
> csm-gh at www.csm-gh.com
> gary.huber at us.army.mil
> ab9m at arrl.net
> www.csm-gh.com/mytrike.htm
> www.csm-gh.com/75thRepoDepo.htm
> 
> 
The feed point of the Bazooka as originally done has two stubs in series
with each other in parallel with the feed point. Those stubs are one
quarter wave long shorted at the other end. So they present a very high
impedance at the band, and at odd multiples of that frequency. Then they
are a half wave long at all even harmonics so the stubs short the feed
point. When cross connected the stubs are in parallel but give the same
frequency effect but are more effective filters. Below the resonant band
the stub impedance gradually decreases to be a short at DC.

73, Jerry, K0CQ