On 5/17/2014 2:29 PM, Wes (N7WS) wrote:
My apologies for confusing two different posters to this thread. Partly
a consequence of threading and me using two different computers and two
different email clients.
I thought that's what having an email client thread emails was supposed
to prevent. Then again, I tried it in T-bird and quickly quit --
couldn't find anything again. :-))
Rick claims that when using a series connection of two different
transmission lines, one coaxial, one window line, changing the length of
one (coax) affects something or the other, while changing the length of
the other portion (window line) has no effect whatsoever.
I could certainly be wrong on this but I believe the post(s) were simply
pointing out that increasing the length of the "balanced" line affects
the losses much less than making it shorter with a correspondingly
longer coax line.
400 or 600 ohm "ladder line" [open wire line with a minimum number of
spreaders] *is* very low loss at HF even at high SWR, so long as the
separation is a very small fraction of a wavelength. That's what the
coastal marine and HF point-to-point stations used in mid-20th century
and KPH/KSM still do. Plastic insulated "window line" is significantly
more lossy than ladder line, but still less than coax at higher SWR's.
Window line is also sensitive to weather conditions. I have window line
down the tower to a DXE 4:1 balun and coax to the shack. KAT500 needs
to retune between a rainy and dry day.
There was a day when we brought open wire line into the shack. With
today's equipment, I really don't recommend that. :-))
73,
Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
