LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #10   Report Post  
Old June 4th 05, 07:06 PM
H. Adam Stevens, NQ5H
 
Posts: n/a
Default

snip

I'm curious -- how did you determine from the SWR that the antenna
impedance would be resistive, and assuming it is, that it would be
less
than 50 ohms rather than greater? Perhaps you've measured a Hamstick
on
a typical mobile mount?

Roy Lewallen, W7EL






Roy spurred me to type:

I use a screwdriver matched with a simple toroidal autoformer.
I tuned the antenna for a purely resistive load using an analyzer.
Turns out it was 20 - 30 ohms on 40 meters, IIRC.
Then I wound 14 turns of copper wire around a toroid, connecting one end to
the coax center
and the other to coax shield and chassis ground.
Then I tapped the antenna on to the autoformer such that,
looking down the coax, the analyzer saw 50 ohms.
I use this matching configuration for 160 - 20.
I get the best VSWR and field strength of many variations I've tried over
the years.
On the higher bands I just hook up the coax and tune for minimum VSWR at the
transceiver.

73, H.,

H. Adam Stevens
NQ5H




 
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
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna RHF Shortwave 1 January 24th 05 09:37 PM
Building a Matching Transformer for Shortwave Listener's Antenna using a Binocular Ferrite Core from a TV type Matching Transformer RHF Shortwave 13 November 3rd 04 08:34 PM
Question...mobile antenna "thinking out of the box"... M-Tech CB 19 August 19th 04 12:46 AM
Help Please! Extremely Poor Reception In Turkey Rich Shortwave 12 December 30th 03 10:43 PM
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 08:31 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