Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old January 13th 05, 06:25 AM
Roy Lewallen
 
Posts: n/a
Default

The fact that superconductors have zero resistance above DC isn't a
limitation of today's technology (although technology limitations cause
current high-temperature superconductors to have resistivity greater
than theoretically possible), but a fundamental property of the nature
of superconductors.

What I'm saying is that a "truly superconducting", "hypothetical
perfect" superconductor has finite resistance at any frequeny above DC.
Imagining a material that has zero resistivity at frequencies above DC
requires imagining something other than a superconductor.

Roy Lewallen, w7EL

Dave Platt wrote:
. . .
Let's assume that you could find a superconductor which would be
truly superconducting even at RF frequencies (which today's
superconductors are not, I gather). So, you could cut the loss
resistance of the antenna to precisely zero, in this hypothetical
case.


. . .
Using the hypothetical perfect superconductor (which may be
impossible) you might reduce this dipole resistance to zero. Great
reduction in loss, right?
. . .

  #2   Report Post  
Old January 13th 05, 11:26 AM
ml
 
Posts: n/a
Default

In article ,
Roy Lewallen wrote:

The fact that superconductors have zero resistance above DC isn't a
limitation of today's technology (although technology limitations cause
current high-temperature superconductors to have resistivity greater
than theoretically possible), but a fundamental property of the nature
of superconductors.

What I'm saying is that a "truly superconducting", "hypothetical
perfect" superconductor has finite resistance at any frequeny above DC.
Imagining a material that has zero resistivity at frequencies above DC
requires imagining something other than a superconductor.

Roy Lewallen, w7EL

Dave Platt wrote:
. . .
Let's assume that you could find a superconductor which would be
truly superconducting even at RF frequencies (which today's
superconductors are not, I gather). So, you could cut the loss
resistance of the antenna to precisely zero, in this hypothetical
case.


. . .
Using the hypothetical perfect superconductor (which may be
impossible) you might reduce this dipole resistance to zero. Great
reduction in loss, right?
. . .


well seems everyone is 'strictly' (narrow) focused on the antenna's
resistence loss, i mentined it as the starting point as that is first
thing i think of when it goes critical... however one the resistance
drops, other effects take place no? both in the material and in respect
to other forces aside from just resistance, once it reaches near 0 and
begins being a superconductor

guess i won't know until i build it and mesure it i wanted to try 10m
really but 2m might be easier to keep chilly(0) and i am looking
foward to rig it i've got most of the stuff i think i need so far

i'd also like to build a superconductie ocilator, i'd suspect that i
could power it using a truly small ammount of power?
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
EH Antenna Revisited Walter Maxwell Antenna 47 January 16th 04 04:34 AM
Poor quality low + High TV channels? How much dB in Preamp? lbbs Antenna 16 December 13th 03 03:01 PM


All times are GMT +1. The time now is 12:05 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