Menu

HELP WITH LADDER LINE CALCULATIONS.

Search this Thread

Prev

Previous Post

Next Post

Next

#4

Report Post

Old

September 24th 09, 11:31 PM posted to rec.radio.amateur.antenna

Owen Duffy Owen Duffy is offline

Owen Duffy is offline

external usenet poster

First recorded activity by RadioBanter: Dec 2006

Posts: 1,169

Default

HELP WITH LADDER LINE CALCULATIONS.

steveeh131047 wrote in news:11c60904-d961-4e70-9b60-
:

....
For example in this month's QST magazine there's an article on using a
40m full-wave loop on 80m. The designer uses a series quarter-wave
section of 450 ohm ladderline to make the impedance "more manageable".
He quotes 300+j8000 at the antenna end of the ladderline. Now plug
those values into Owen's calculator, using something like Wireman 551
for the line, and you'll get 7dB of feedline loss.

Steve,

It may even be worse than that as TLLC models skin effect in a
homogenouse conductor, and some ladder lines use copper clad steel that
will have higher loss at the low end of HF where the coating thickness is
less than several skin depths. This is especially true of the more
expensive stranded CCS types.

But, yes... QST runs stories from time to time that reinforce the myth
that ladder line is so good that you *never* need to consider its loss.

Here is are reviews of a couple of older articles discussing the relative
merits of ladder line and coax:

http://vk1od.net/blog/?p=316

http://vk1od.net/transmissionline/LOLL/

Owen

Reply With Quote

Reply With Quote

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search
Display Modes
Switch to Linear Mode Switch to Hybrid Mode Threaded Mode

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
HELP WITH LADDER LINE CALCULATIONS.	justme	Antenna	1	September 24th 09 08:59 PM
ladder line??	W3CQH	Antenna	5	June 11th 08 02:15 AM
Using Twin Lead or Ladder Line for your Antenna's Feed-in-Line ? - Then 'consider' a Pair of Vintage Style TV Antenna Clips . . .	RHF	Shortwave	11	December 29th 05 04:05 AM
Feed Line Length - Ladder Line	Pat Whelton	Antenna	10	July 7th 05 12:54 AM

All times are GMT +1. The time now is 03:51 PM.

About Us

"It's about Radio"

Contact Us RadioBanter forum home Privacy Statement

Copyright © 2017