LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #19   Report Post  
Old April 9th 04, 07:25 PM
Dave Platt
 
Posts: n/a
Default

In article fxzdc.143$cD2.12959@attbi_s51,
Dave Shrader wrote:

IMO applying the word 'Gain' to an antenna is misuse of the word 'gain'.


Since this particular terminology has been used in this way in both
amateur and professional antenna literature for more decades than I've
been alive (I'm pushing 50) I think you're tilting at windmills to try
to eliminate it, or to declare it "misuse".

I personally prefer to refer to what an antenna delivers as
"directional gain", to distinguish it from the sort of "more RF out
than RF in" power gain that an amplifier delivers. From the point of
view of someone trying to deliver a specified amount of power to a
receiver in a specified direction, the two types of "gain" can be
interchanged to a large degree.

Yes, they're distinct, and we need to remember the distinctions, but
they can be traded-off against one another in many common sorts of
calculations.

[At the risk of re-opening a topic of contention, I'll posit that the
use of the term "gain" to refer to both amplifier power gain and to
antenna directional gain is somewhat similar in spirit to the use of
the term "resistance" to refer to both dissipative and nondissipative
impedances. Each is a single term, referring to two different
phenomena which can under many circumstances behave in ways which can
look equivalent from a particular point of view.]

Next question: where do I get a 160 meter 1/2 wavelength 50 ohm slotted
line?


Go down to your nearest abandoned rust-belt factory that has a large
brick or concrete chimney, wrap the chimney with sheet tin (leaving a
slot), and drop a suitable-sized silver-plated cast-iron sewer pipe
down the center. Run your probe up and down the chimney on a huge
pulley.

It'll probably be tricky to couple this to the antenna and feedline,
though. I don't think even Andrews makes a heliax connector quite
this large.

grin


--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
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
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 11:39 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