[Elecraft] searching for post by Wayne n6kr about counterpoise

[Don Wilhelm]

Tom and all,

One of the KX2 Field Testers found that a 58 foot resonator and a 26 
foot counterpoise worked well on 80 through 10 meters.
I use half those lengths for 40 through 10 meters.
No feedline, both the radiator and the counterpoise are connected 
directly to a BNC to Binding Post adapter on the KX2.

The direction of the counterpoise does not make a lot of detectable 
difference.  Antenna modeling may show some difference, but working 
quickly in the field may not allow you to set up the "perfect" situation 
- use what you have available.

The KX2 internal tuner is a wide range tuner that might even be able to 
match a metal window frame or the proverbial "bedsprings".

Let's face it, this is a compromise antenna that can be thrown into a 
tree and give us the opportunity to make QSOs in the field.  For home 
station use, a proper antenna up in the air will be better.

73,
Don W3FPR

On 9/8/2018 9:50 AM, Tom McCulloch wrote:
> This is probably NOT what you are looking for but it's about random 
> length antennas...it goes back to Jan 29, 2017.
> 
> hope this helps:
> 
> I'd call an ad-hoc antenna that works on multiple bands with an ATU a 
> "Kinda-Random Antenna" (KRA). (Apologies to linguistic purists.)
> 
> A simplified definition might be:
> 
>    A. long enough to work within the maximum limits of the ATU's 
> L-network on the lowest band used
>    B. presents a reasonably low impedance on all bands used (e.g., 
> doesn't look like an end-fed half-wave)
> 
> ATUs have limited monotonicity and granularity, as well as stray 
> impedances, so in practice there is a third criteria:
> 
>    C. tunable on each band used despite specific L-network idiosyncrasies
> 
> This third criteria is the hardest one to predict for a given ATU 
> design, as the idiosyncrasies vary with PCB layout and actual component 
> values. They may only impact the highest bands, or for a particular 
> antenna, the bands on which Q is the highest. For our ATU designs, we 
> try to minimize strays and keep the network monotonic by using tightly 
> toleranced capacitors and toroidal inductors.
> 
> While a wide range of wire lengths will meet the requirements of a "KRA" 
> in the field, we've found from experience that something in the 25'-28' 
> range works on all bands from 40 meters up, and roughly twice this for 
> 80 meters up. Since it's impossible to predict the effect of ground 
> losses, obstructions, deployed wire angles, etc., you may occasionally 
> need to add or remove wire to obtain resonance on all bands used.
> 
> 73,
> Wayne
> N6KR