[Elecraft] Is a K3 ATU with balanced outputs possible?

[Eric Buggee]

Hi Andrew, Don & all,

I have a K3 (4520) and have recently installed a new antenna in the form 
of a "V" beam with the bisector at about 7 Degrees east of North, with 
the included angle at about 70 degrees and a leg length of 285Ft, height 
above ground is 70 to 75 Ft, with ground sloping down away to N & NE for 
20Km.

I have found that using the KAT3 in the K3 and a BL2 Balun it is useable 
on all bands from 160 through to 6M with the worst VSWR of 1.5:1 showing 
up on 160 at 1860KHz.

Reports from stations at, 1 to 5000 Km north from Emerald in the ranges 
60 KM East of Melbourne in VK3 land give the "V" beam an advantage of 2 
to 3 Sunits over the main antenna running NE to SW (A full sized 160M 
dipole at 105Ft, fed with OW line spced 6inches) .

Reports run as follows:-  160M, generally 1 S unit down WR to the 160M 
dipole;

80M, equal to & sometimes 1 S unit better (on average) compared to the 
160 M dipole appears to be dependent upon time of day & prop'n conditions;

40M, definitely better with 1 to 2 S units better most of the time (day 
or night);

30 M, definitely better by consistent 2 to 3 Sunits better at 3 to 5000Km;

20 M like 30 M consistently better than the 160 M dipole by 2 to 3 S 
units at 3 to 5000Km distance.

The higher bands, with the V Beam I am hearing DX stations that are not 
even detectable on the 160 M dipole (8 & 24MHz), but, so far no 
definitive contacts made using the V beam to give a real evalution as 
yet.  It has only been operational for about 10 days.

Hope the foregoing is of interest,

73,

 From Eric VK3AX.



On 9/29/2012 9:06 AM, Andrew Moore wrote:
> Great; thank you for the trivia, very helpful. I figured it had already
> been considered and that there was a good reason for the current
> configuration.
>
> The BL2 following the KAT3 was exactly one option I was considering. I've
> read about several cases in which ops had success, but read others in which
> the balun was heating perhaps due to excessive reactance on the antenna
> side. Reactance is likely dependent on the frequency/band and several
> factors in the antenna system which could explain the mixed results.
>
> I think I will try this approach and enjoy the experimenting.
>
> All: Not looking to turn this in to an OT antenna theory thread, but if you
> have specific experience with this configuration, I'd like to hear (KAT3 to
> BL2 to ladder to simple dipole).
>
> Thanks,
> --Andrew, NV1B
> maineware.net
> ..
>
>
> On Fri, Sep 28, 2012 at 6:43 PM, Don Wilhelm <w3fpr at embarqmail.com> wrote:
>
>> Andrew,
>>
>> A bit of 'trivia' first:
>> That was "supposed" to be a solution in the KAT500 tuner.  The initial
>> design put the balun on the input of the tuner, and attempted to "float"
>> the rest of the tuner while trying to maintain balance.
>>
>> There were problems with maintaining balance through the rest of the
>> tuner, while studies indicated there was no efficiency difference between
>> the balun at the input vs. the balun at the output, so the design was
>> changed to an unbalanced design driving (if required or desired) a balun at
>> the output of the tuner.
>>
>> "trivia off":
>>
>> So more specific to your question, a balanced output from the K3 KAT3 can
>> easily be obtained by using an Elecraft BL2 on the output side of the KAT3.
>>
>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>