Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #11   Report Post  
Old September 30th 03, 05:11 PM
Brian
 
Posts: n/a
Default

Dan Richardson wrote in message . ..
On 18 Sep 2003 08:21:43 -0700, (Howard) wrote:

Hello to all,

I have looked with interest at the new Ten-Tec Vee Beam Terminated
antenna. Is there a guru on the list who has the knowlege to share on
how to duplicate this antenna?

It is a vee beam with each leg terminated to ground with a resistor,
and there is a balun of sorts at the input.

I remember an antenna similar to this years ago, and I think ten-tec
will have a winner with this if folks can get away from the supposed
"horror" of a terminated antenna.

Details at
www.tentec.com

I wish I could afford it at this time!!

Regards, Howard


Running a model with an apex angle of 90º as per the illustration on
page one of their Installation and Operation manual. NEC reports the
following maximum forward gain:

Using 50 foot arms

Freq. MHz Gain dBi Elevation Angle

3.5 -13.8 80º
7.0 -5.3 55º
14 -1.8 33º
21 5.63 23º
28 6.51 47º

Using 100 foot arms

3.5 -9.4 64º
7.0 -1.06 47º
14 4.51 25º
21 4.35 17º
28 3.24 57º


Danny, K6MHE


Danny, can you give us a match/swr for each band? The antenna is
supposed to not need matching.

Brian
  #18   Report Post  
Old October 3rd 03, 12:29 AM
Dan Richardson
 
Posts: n/a
Default

On 2 Oct 2003 10:24:25 -0700, (Brian) wrote:

Dan Richardson wrote in message . ..
On 30 Sep 2003 09:11:02 -0700,
(Brian) wrote:


Danny, can you give us a match/swr for each band? The antenna is
supposed to not need matching.

Brian


Brain,

According to the manual the antenna uses a 50 to 800 Ohm broadband
matching transformer at the feed point. Assuming then that the
antenna's feed point should be near the 800-Ohm figure I ran a sweep
for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to
calculate the SWR. I got the following results:

3.5 1.40:1
7.0 1.88:1
10.1 1.92:1
14.2 1.96:1
21.2 2.37:1
28.5 2.41:1

Those figures appear to be in close agreement with the manufacture's
claim.

That said I feel that worrying about the SWR's effects on antenna
operation is somewhat like worrying how well a car will run based on
the amount of air pressure in the tires.

73
Danny, K6MHE


Danny, thanks for running the numbers. I appreciate it.

And feel free to drive your car w/o air pressure in your tires. Maybe
you've got the Presedential and Armored Car series tires. Since I
don't, I prefer air in my tires, and in my antennas, I prefer an SWR
somewhat below my transmitter's SWR protection circuit's limit.

73, BrIan/N0IMD


I guess I choose a poor analogy regarding SWR. On my list SWR is the
least of my worries as it is one of the easiest to fix. I would be
much more interested in the antenna's pattern (launching the signal in
a direction and angle I wish), what amount of gain it has at that
direction/angle and what efficiency it operated at.

Back to the analogy of a car. I would be more interested in how the
engine ran, transmission worked and so forth. A flat tire (read
excessive SWR) is easy to fix but rebuilding an engine is another
matter.

73 Danny

  #19   Report Post  
Old October 3rd 03, 12:29 AM
Dan Richardson
 
Posts: n/a
Default

On 2 Oct 2003 10:24:25 -0700, (Brian) wrote:

Dan Richardson wrote in message . ..
On 30 Sep 2003 09:11:02 -0700,
(Brian) wrote:


Danny, can you give us a match/swr for each band? The antenna is
supposed to not need matching.

Brian


Brain,

According to the manual the antenna uses a 50 to 800 Ohm broadband
matching transformer at the feed point. Assuming then that the
antenna's feed point should be near the 800-Ohm figure I ran a sweep
for 3.5, 7, 10.1, 14.2 and 28.5 MHz referencing a 800-Ohm impedance to
calculate the SWR. I got the following results:

3.5 1.40:1
7.0 1.88:1
10.1 1.92:1
14.2 1.96:1
21.2 2.37:1
28.5 2.41:1

Those figures appear to be in close agreement with the manufacture's
claim.

That said I feel that worrying about the SWR's effects on antenna
operation is somewhat like worrying how well a car will run based on
the amount of air pressure in the tires.

73
Danny, K6MHE


Danny, thanks for running the numbers. I appreciate it.

And feel free to drive your car w/o air pressure in your tires. Maybe
you've got the Presedential and Armored Car series tires. Since I
don't, I prefer air in my tires, and in my antennas, I prefer an SWR
somewhat below my transmitter's SWR protection circuit's limit.

73, BrIan/N0IMD


I guess I choose a poor analogy regarding SWR. On my list SWR is the
least of my worries as it is one of the easiest to fix. I would be
much more interested in the antenna's pattern (launching the signal in
a direction and angle I wish), what amount of gain it has at that
direction/angle and what efficiency it operated at.

Back to the analogy of a car. I would be more interested in how the
engine ran, transmission worked and so forth. A flat tire (read
excessive SWR) is easy to fix but rebuilding an engine is another
matter.

73 Danny

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 10:22 PM
Yaesu FT-857D questions Joe S. Equipment 6 October 25th 04 09:40 AM
Mobile Ant L match ? Henry Kolesnik Antenna 14 January 20th 04 04:08 AM
Poor quality low + High TV channels? How much dB in Preamp? lbbs Antenna 16 December 13th 03 03:01 PM
QST Article: An Easy to Build, Dual-Band Collinear Antenna Serge Stroobandt, ON4BAA Antenna 12 October 16th 03 07:44 PM


All times are GMT +1. The time now is 12:34 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017