[Elecraft] Counterpoise vs ground wire ?

[Fred Jensen]

On 7/1/2012 11:49 AM, Ronald Nutter wrote:
> I am putting together a portable QRP kit that I can fly on a plane with
> me.  Looking at several different antennas.  With being a portable
> operation, what has worked best for some of you to ground the radio ?  I
> am seeing references to some of the antennas that they need a
> counterpoise wire.  Is this in addition to a ground wire ?

You might want to subscribe to the NA SOTA Yahoo Group Ron.  SOTA is 
"Summits On The Air," analogous to IOTA.  www.sota.org.uk is the main 
site.  www.sotawatch.org is the site where alerts and posts are made. 
Light, efficient portable antennas are a big subject among the 
Summiteers and there are people there who can probably point you in 
useful directions.

There are several folks in the NA SOTA crowd who use end-fed half-wave 
antennas on summits very successfully [Fred, KT5X is one].  You're 
feeding a very high impedance, so you need a matching network such as 
the one that Stu, KI6J, designs.  EFHW's have the advantage that they're 
just wire [mine is on a little reel, I just pull out to the mark for 
that band] so they're very light and simple.  Theoretically, they 
shouldn't need a return path, however mine is much easier to cram power 
into with about 8 inches of wire hanging off the shield of the coax at 
the radio on 20m.  Oddly, EZNEC confirms it, YMMV.

Another SOTA ham is Mike, KD9KC, in El Paso.  He's been using the 
AlexLoop magnetic loop antenna and has very good things to say about it. 
  It is a little pricy compared to a half wavelength of wire, but Mike 
carries his to some fairly high summits and on long hikes.  It shouldn't 
be that hard to build one from scratch.

If you're outside and worried about grounding for lightning, you 
shouldn't be outside. :-)  If your radio is battery powered, AC mains 
safety grounding isn't really an issue.  It's always a good idea to make 
sure the antenna connector has a high value resistor [~100K] across it 
to bleed precip and wind/dust static.

73,

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