I thought about lumped components for the delays. I did not have time
to evaluate a lumped-component system for maintaining the desired
phasing over the entire band. Did you look into this aspect, Rick?
-- Eric
on 2010 Jun 20 22:12 Richard (Rick) Karlquist said the following:
> I built a loop the same size as in the forum paper and the bandwidth
> was something like 10% of what was shown. I used critical coupling
> (ie a conjugate match). In order to cover the whole 160 meter band,
> it would have been necessary to greatly over-couple to drastically
> lower the loaded Q. This is easy to do by simply reducing the
> turns ratio. This would result in a sensitivity reduction of 10
> or 20 dB. This might be OK in the usual noisy environment. OTOH,
> I'm not sure that many people need the whole 160 meter band. My
> loop is described in the Sept/Oct 2009 National Contest Journal.
> It is not intended to use in an array.
>
> In the forum article, I don't understand the impedance step
> from 1 to 2 on page 49. It appears that the resistor is more
> like 20 ohms than 2 ohms. In any event, considerable degeneration
> is happening somehow. The forum article criticizes W8JI's
> swamping technique but seems to follow suit.
>
> The combining network uses 100's of meters of phasing lines.
> These are easily replaced by their lumped element equivalents:
>
> http://www.n6rk.com/Lumped_LC_Delay_Networks.gif
>
> Rick N6RK
>
>
>
> Luis Mansutti IV3PRK wrote:
>
>> Hi Topbanders,
>>
>> I read the very fine presentation by Eric Scace, K3NA, at 2009 Dayton
>> Antenna Forum on a new Rx Loop Array.
>> http://www.kkn.net/dayton2009/dayton-2009-antenna-forum.html
>>
>> I like to test every kind of Rx antenna, but the matching of this array
>> seems (to me) not as simple as with verticals or flags.
>> I don't understand the 4-stage network and the related K2TJ monte carlo
>> analysis.
>>
>> Did anybody get inside this project, or tried to build it ?
>>
>> Thanks in advance for any comment.
>>
>> 73
>> Luis IV3PRK
>>
>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
>>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|
