Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old December 12th 04, 06:56 PM
William H. O'Hara, III
 
Posts: n/a
Default Loop Antenna

Does anyone have an idea regarding the affect of
a T shaped loop? I know that a circle has larger
ap then a delta loop or square loop. Would an effect
be realized with a T?

Bill
N1EY
  #2   Report Post  
Old December 12th 04, 07:59 PM
Duane Allen
 
Posts: n/a
Default

William H. O'Hara, III wrote:
Does anyone have an idea regarding the affect of
a T shaped loop? I know that a circle has larger
ap then a delta loop or square loop. Would an effect
be realized with a T?

Bill
N1EY


Start at an extreme case for the T. If the two conductors of the T's
stem are close together, then your T loop's stem is going to act like
open feedline. If the two conductors of the T's top are close together,
then your T loop's top is going to act a folded dipole.

Opening parellel sides of the stem or/and the top makes the structure
move towards becoming a square (rectangular) assembly.

If you keep the lower end of the stem close together and widen the top
of the stem, then the T moves towards an inverted delta assembly.

Duane
N6JPO
  #3   Report Post  
Old December 12th 04, 09:13 PM
Reg Edwards
 
Posts: n/a
Default

I would think such an antenna would be difficult to adjust to avoid
adverse
phase interactions...


================================

On the other hand there are an equal number of advantageous interactions.


  #4   Report Post  
Old December 12th 04, 09:27 PM
Hal Rosser
 
Posts: n/a
Default


"William H. O'Hara, III" wrote in message
. 97.142...
Does anyone have an idea regarding the affect of
a T shaped loop? I know that a circle has larger
ap then a delta loop or square loop. Would an effect
be realized with a T?


sounds like a folded dipole. - and it should act like one too.
you'll find that if you can move the 'vertical' part of the 'T' (feedpoint)
using a pully setup, that the arrangement can be used for several bands.
put a 4-1 balun at the bottom of the T.



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.807 / Virus Database: 549 - Release Date: 12/7/2004


  #5   Report Post  
Old December 12th 04, 11:01 PM
William H. O'Hara, III
 
Posts: n/a
Default

"Hal Rosser" wrote in
:


"William H. O'Hara, III" wrote in
message
. 97.142...
Does anyone have an idea regarding the affect of
a T shaped loop? I know that a circle has larger
ap then a delta loop or square loop. Would an effect
be realized with a T?


sounds like a folded dipole. - and it should act like one
too. you'll find that if you can move the 'vertical' part
of the 'T' (feedpoint) using a pully setup, that the
arrangement can be used for several bands. put a 4-1 balun
at the bottom of the T.


What happens if I do this,

300 feet
--------------------
| | 1
| | 0
| 100 ft 100 ft| 0
|_____ ______| ft
| |
| | 9
| | 0
| | f
|_______| t
FEED


Any thoughts?

Thanks
Bill N1EY



  #6   Report Post  
Old December 13th 04, 12:33 AM
Roy Lewallen
 
Posts: n/a
Default

The free demo version of EZNEC available from http://eznec.com can
easily answer questions just like this.

Roy Lewallen, W7EL


William H. O'Hara, III wrote:

What happens if I do this,

300 feet
--------------------
| | 1
| | 0
| 100 ft 100 ft| 0
|_____ ______| ft
| |
| | 9
| | 0
| | f
|_______| t
FEED


Any thoughts?

Thanks
Bill N1EY

  #7   Report Post  
Old December 13th 04, 03:05 AM
William H. O'Hara, III
 
Posts: n/a
Default

Roy Lewallen wrote in
:

The free demo version of EZNEC available from
http://eznec.com can easily answer questions just like
this.


It refuses to calculate SWR due to multiple wires
running so close would create interactions.

Bill
  #8   Report Post  
Old December 13th 04, 06:04 AM
Roy Lewallen
 
Posts: n/a
Default

There shouldn't be any problem with that antenna. Please send me the
description (.EZ) file as an email attachment, and I'll look it over.

Roy Lewallen, W7EL

William H. O'Hara, III wrote:
Roy Lewallen wrote in
:


The free demo version of EZNEC available from
http://eznec.com can easily answer questions just like
this.



It refuses to calculate SWR due to multiple wires
running so close would create interactions.

Bill

  #9   Report Post  
Old December 13th 04, 06:23 AM
Ken Fowler
 
Posts: n/a
Default


On 12-Dec-2004, "William H. O'Hara, III" wrote:

Roy Lewallen wrote in
:

The free demo version of EZNEC available from
http://eznec.com can easily answer questions just like
this.


It refuses to calculate SWR due to multiple wires
running so close would create interactions.

Bill


Hi Bill,

Not sure about EZNEC Demo, but EZNEC 3.0 models it and gives Source Data (SWR) in the 600 to 1200
ohm range. Maybe you should check your connections and try again. For what it's worth, the pattern
is like most large horizontal loops, except for two large lobes in the direction of the top corners
of the tee.

Ken Fowler
  #10   Report Post  
Old December 14th 04, 04:50 AM
William H. O'Hara, III
 
Posts: n/a
Default


I did quickly in the middle of the night. I will
look it over and see I can find some problem with
the wires. I used EZNEC demo 4.0.

Thanks
Bill

Maybe you should check your connections and try again. For
what it's worth, the pattern is like most large horizontal
loops, except for two large lobes in the direction of the
top corners of the tee.

Ken Fowler


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Inverted ground plane antenna: compared with normal GP and low dipole. Serge Stroobandt, ON4BAA Antenna 8 February 24th 11 11:22 PM
The "TRICK" to TV 'type' Coax Cable [Shielded] SWL Loop Antennas {RHF} RHF Antenna 27 November 3rd 04 02:38 PM
Poor quality low + High TV channels? How much dB in Preamp? lbbs Antenna 16 December 13th 03 04:01 PM


All times are GMT +1. The time now is 06:20 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017