Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #11   Report Post  
Old November 12th 03, 12:53 AM
Dave VanHorn
 
Posts: n/a
Default


If you have a 1.5 swr your antenna isn't resonant


Sorry, but thanks for playing.

Your resonant impedance may be pretty much anything, depending on the exact
antenna in question. We favour antennas that are roughly 50 ohms resistive
at resonance.

Resonance is the point(s) where the antenna has little to no reactive
impedance component.

My cobra for 11M is about 2/1 and is definitely resonant.



  #13   Report Post  
Old November 12th 03, 10:09 PM
Frank Gilliland
 
Posts: n/a
Default

In , Radioman wrote:

If you have a 1.5 swr your antenna isn't resonant


Tnom, Frank, smack his pee pee until he understands that 1:1 and resonance
are related but different. You can have one without the other.

Tell you what, put a 102 inch stainless steel whip on the roof of your clunker.
Use a 4 inch heavy duty spring. Use enough coax to reach the radio. Measure SWR.

Tell us what you get. Respond before December 31st.



Let's clear up a few CB myths here.......

First, the ONLY thing an SWR meter can tell you is how much power -inside- the
coax is going in the wrong direction. It -can't- tell you why. SWR does not
distinguish between an antenna and a dummy load, nor does it care about errors
due to improper or untuned grounds, RF on the coax, the length of the coax, the
type of antenna, etc, etc, etc. In fact, an SWR meter can show a 1:1 ratio with
no load at all depending on your coax length and whether the end is open or
shorted -- it's called a tuned stub!!!

Second, it is the -efficiency- of the antenna that is important. This should be
a rule: If you want resonance, use a grid-dip oscillator; if you want maximum
field strength, use a field strength meter. (duh!) If anyone wants proof of
this, plot the SWR and the relative field strength across the band -- you will
find that they peak at different frequencies.

Finally, the SWR meter is good as an indicator of fault or failure in a working
antenna system, and then only if you know what the SWR should be when the system
is working properly. That's the way it should be used. It should -not- be used
to tune an antenna. A field strength meter is less expensive, easier to use, and
directly measures the strength of the transmitted signal (which is what you
really want to measure anyway!).








-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
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
Sneaking tiny radios into North Korea Mike Terry Broadcasting 0 November 13th 04 05:02 PM
Comparison of six portable radios lsmyer Broadcasting 0 June 15th 04 01:21 AM
export cb radios I Am Not George Policy 12 March 30th 04 12:44 PM
MOTOROLA RADIOS for Sale! John Equipment 0 January 30th 04 03:56 PM
FS MOTOROLA RADIOS HT1000'S , VISAR'S ,& MAXTRAC'S John Equipment 0 January 19th 04 05:44 AM


All times are GMT +1. The time now is 01:15 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