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

[Eric Buggee]

On 9/29/2012 10:04 AM, Eric Buggee wrote: Addendum to my original post.
> 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 should have added: the following".

   " The feed line from the BL2 which is mounted under the eaves of the 
shack with about 3M of RG58  to the K3.
      From the BL2 at 10Ft above ground to the V beam I have a run of 
73Ft of Ladder Line with 14Gauge Copperweld conductors."
>
> I have found that using the KAT3 in the K3 and the 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.
>>>
>>>
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>