LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #11   Report Post  
Old November 18th 09, 05:06 PM posted to rec.radio.amateur.antenna,alt.internet.wireless
external usenet poster
 
First recorded activity by RadioBanter: Jun 2007
Posts: 1,336
Default Matching on the MFJ-1800

On Wed, 18 Nov 2009 07:00:26 -0600, "amdx" wrote:

The CENTER of the driven element (the plastic screw hole) to the
CENTER of the last director is 36.7cm (14-7/16")


Thanks. My numbers came out to 36.52 cm which is close enough.

ALL directors or the same length (within .003")
They are 46.6mm in length.


Amazing...

Also, measure the coax balun cable dimensions. Mostly, I'm interested
in the:


Nice. I'll see if I guess(tm) the coax type. It doesn't seem like a
good fit for any of the common cables as the center conductor is
somewhat larger diameter than any of these listed. See if you can
find an exposed center conductor without any tinning or soldering.
http://www.epanorama.net/documents/wiring/coaxcable.html
One more dimension... the approximate outer jacket diameter of the
coax (not including the shrink tube).

My guess is solid poyethylene, if you have a test other than poking it
with a pin to get feel of it, which I did.


Weird(tm). Low loss coax would need to be foam or teflon. Solid
polyethylene is easier to work with, cheaper, but not the best.
However, a short piece like this balun would not have much loss, so I
guess it doesn't matter what flavor is used:
http://en.wikipedia.org/wiki/Coaxial_cable

Gotta do paying work today. I'll play with this more in the next day
or two (so I don't forget what I'm doing).

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
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
WTD: Drake SL-1800 Filter Ed[_2_] Boatanchors 0 March 15th 08 11:25 PM
Panasonic RE-1800 scanner mike maghakian Scanner 1 October 26th 06 03:23 PM
PCB Antenne for GSM (900/1800) PeterCreppa Antenna 0 May 26th 04 03:03 PM
GSM patch antenna (900/1800/1900 MHz) ? charlie Antenna 3 February 18th 04 05:15 AM
1800 Watts PEP on .555 CB 8 October 7th 03 03:29 AM


All times are GMT +1. The time now is 10:14 AM.

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