[Elecraft] Travel antennas - outside with rig inside

[Fred Jensen]

Steve,

28 ft is close to 1/4 wave on 40, placing the current node at your rig 
[low Z].  Radiation occurs primarily from the higher current portions of 
the conductor(s), and with 5 ft inside, that's 18% of your physical 
antenna, and perhaps 25% of the portion with significant currents, inside.

On 20, it is approaching a half-wave and will have a very high Z at the 
connection to the rig, and you may or may not be able to match it with 
an internal tuner.  Don't know which Elecraft rig you're using.  Other 
comments interspersed below.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2012 Cal QSO Party 6-7 Oct 2012
- www.cqp.org

On 7/20/2012 3:54 AM, Steve KC8QVO wrote:
> I am out of town this weekend and brought my 28' random wire/counterpoise. I
> have the random wire and counterpoise going out the window about 5' away.
> The tip of the random wire goes up in a tree about 15' up. The counterpoise
> goes out the window the opposite direction weaved through some bushes (to
> keep off the ground) about 5' up.

If the counterpoise is elevated, you have basically a highly distorted 
dipole ... with the portions that radiate the most inside.  On the 
ground, you have a somewhat distorted 1/4 wave "vertical," highest 
current section inside, with one radial. :-)  Either will work.  Getting 
the high current parts outside will make it work a lot better.
>
> The antenna seems to perform a ton better in a portable set up outside.
> There are signals I can hear on 40, but they are much weaker than if I set
> up outside.

Not surprised

> Wire is #26 Silky Wire from The Wireman (my favorite).

Doesn't really matter although the non-tangle stuff is a lot easier to 
deploy.
>
> I am thinking for this kind of set up I need to get the feedpoint OUTSIDE
> the window. Right now the wires come through the window and attach to the
> rig with a BNC-binding post adapter.

Yeppers.  See top post.
>
> I believe getting the feedpoint outside the window requires a coax cable and
> external tuner. Does anyone have any ideas on running the tuner inside the
> rig that may work without coax?

A 5' run of RG-58 on 40 meters is of little consequence, and a KX1 or K2 
internal tuner should match it well.  It would be a real good idea to 
have a current choke at the far end of the coax, similar to the coax 
that comes with a Buddipole.  That will get the whole antenna outside 
and minimize the imbalance and common mode currents on the outside of 
the coax shield.
>
> Balanced feed lines will still detune through the window frame too,

Actually, not so much at all.  You would need a balun to get to 
unbalanced coax to get into the rig.  Just 5 ft of coax is a lot easier.