[Elecraft] 270 foot (ish) Doublet & K3 ATU

[Fred Jensen]

On 5/15/2014 12:22 PM, Iain G4SGX wrote:
> Hello,
>
> Does anyone use a 270 foot doublet with the K3 ATU?

Yes
>
> Is there a combination of feeder type/length and Balun type & coax
> length that tunes OK on 160-10?

My primary 40/60/80/160 antenna is a center-fed dipole in an inverted-V 
configuration.  The apex is at 70 feet [~21 m] and the ends are elevated 
enough that no one runs into them.  The legs are 135 ft [~41 m] long. 
It is fed with 450 ohm ladder-line down the tower to a DXE 4:1 balun at 
the base of the tower and RG-213 to the shack.

The ATU's in my KX1, K2, K3, and the KAT500 all match it fine, even on 
30, 17, and 12 m.  Admittedly, the radiation angle is higher than 
optimum on 160 [I put up an inverted-L in the winter for that], and on 
17 and 12 m, it squirts RF in all sorts of directions, not all 
desirable, but the ATU's all work fine with it.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org