[Elecraft] KX3 & Loop Antennas

[Phil Wheeler]

Re "Try it with 1 KW, it will really surprise 
you.  And sadly, I don't think a Reynolds Wrap hat 
will protect you if you're close.: Not to worry, 
because the AlexLoop would fail very quickly if 
subjected to a kW!  I'd not want to be under it or 
anywhere near it in that case.

73, Phil W7OX

On 5/30/16 5:13 PM, Fred Jensen wrote:
> I replaced my Buddipole with an Alex and use it 
> a lot in the field ... understand that as I 
> accumulate birthdays, "field" more and more 
> means a drive-to a park or friendly hill. It 
> works better than the BP ever did, I can set it 
> up in 5 min, it is fairly insensitive to ground 
> and surrounding objects, including me.  I sit 
> under it so I can reach the knob.
>
> It's a resonant transformer.  To be effective, 
> it must be EXACTLY resonant.  That's a bit 
> touchy on 30 and 40.  You MUST bypass the ATU. 
> "Getting close" with the knob and then letting 
> the ATU do it's matching job yields a fairly 
> pricey dummy load.  On 40, the BW of the Alex 
> isn't much more than a SSB signal.
>
> Beware:  Small mag loops can involve some huge 
> circulating currents and RF voltages.  The Alex 
> is OK to 10W.  Google "magnetic loop calculator" 
> for a very cool little calculator.  Try it with 
> 1 KW, it will really surprise you.  And sadly, I 
> don't think a Reynolds Wrap hat will protect you 
> if you're close.
>
> Small mag loops are bi-directional in the plane 
> of the loop but it is very broad.  Orthogonal to 
> the loop plane, there are two very sharp, deep 
> nulls, sometimes useful to eliminate noise from 
> a point source or QRM.
>
> 73,
>
> Fred K6DGW
> - Northern California Contest Club
> - CU in the Cal QSO Party 1-2 Oct 2016
> - www.cqp.org
>
> On 5/30/2016 4:38 PM, TFJM via Elecraft wrote:
>> Has anyone had much success using either an 
>> Alex Loop or Chameleon P Loop
>> antenna with their KX3? I have few antenna 
>> options in an apartment situation
>> and throwing a 25 foot long wire into a nearby 
>> tree has not worked for me.
>> Even tried loading up a 33 foot long aluminum 
>> balcony railing with no luck.
>>
>> Thanks,
>> Tom W1PDI