That's a good idea, but it's best if the antenna isn't exactly full wave.
Don't use the formula. For example, my multiband antenna for 80/40/30/20/17/15
is 150 feet long, with ladder line all the way to the shack. Making it 130 -
135 feet would make it harder to tune on 80 without giving me any benefit.
73,
Cathy
N5WVR
--------------------------------------------
On Sun, 4/24/16, KA1LHZ <sboard.ka1lhz@xxxxxxxxx> wrote:
Subject: [CVARC] Re: CW VT practice net starts Monday night
To: cvarc@xxxxxxxxxxxxx
Date: Sunday, April 24, 2016, 9:21 AM
Or you could feed it with ladder line right to the tuner. I do that
as do several others on the 1930 kc Toad Harbor Net. My antenna
loads up on 20 through 160. I've worked Australia on 20 with it.
73
DE KA1LHZ
On 04/10/2016 08:41 PM,
Catherine James
wrote:
No
surprise
that a 160 dipole doesn't want to
load on 80. Center
fed dipoles don't like even
harmonics, but will work
on odd harmonics. But most amateur HF
bands are even
harmonics of each other, so except for
40/15 that
doesn't help.
That's why my
40 meter dipole is off-center fed. If
you feed at
about one-third of the way from one end
toward the
other, you'll get a consistent
impedance on the
fundamental and even harmonics. So I use
it on 40,
20, and 10, and all are
SWR
less than 2. (Typically
around 1.7 or better)
The
catch is
that the feedpoint impedance is about
150-200 ohms,
so you need a 4:1 balun transformer at
the
feedpoint.
I'm not
suggesting you modify your 160 dipole to
off-center
feed, but it's a useful trick to
know.
73,
Cathy
N5WVR
Sent
from Yahoo Mail on
Android
From:"Alan Zaur"
<alanlzaur@xxxxxxxxx>
Date:Sun, Apr 10, 2016 at 7:55 PM
Subject:[CVARC] Re: CW VT practice
net starts
Monday night
Hi Ed,
I am also going to be putting up
some new wire
this year. Maybe we should get the
F.A.R.T.
together. I have a pneumatic
launcher, etc. Be
thinking of you tomorrow.
Alan
Sent from my iPhone
> On Apr 10, 2016, at 7:29 PM,
Ed
Hutchinson <ehutch@xxxxxxxxx>
wrote:
>
> Hi Cathy,
> Thanks for the notice about
the CW
practice net.
> I think I will "listen
only" at least the
first week or perhaps two. The
only antenna I
have up right now is a 160m
dipole. I just
tried to load it in several places
in the 80m
band and I can't get better
than 6:1 with a
tuner anywhere. It seems to work
tolerably on
40m, 20m, 15m, and 10m (not 1:1
but usable),
but nothing doing on 80.
>
> We have our annual Green
Mountain Chorus
concert this week and I will be
traveling up
to Winooski or Essex Jct several
times this
week (tomorrow, and Tues, and
Friday, and
Saturday). Who would have thought
singing
would have such a big carbon
footprint.
>
> There is little chance that I
will hang
up an 80m dipole tomorrow (but I
should be
home by 7:00 or soon after to
listen, if I can
find the group). The GMC tech crew
is meeting
at EJHS at 2:00 (for an hour or
two - if one
believes that). I know I have
several
multiband antennas and I think at
least one
80m 1/2wave wire cut with coax
attached. But
they are out in the barn
somewhere, and I will
need to figure out where to hang
one.
>
> Ed, n1fmp
>