[Elecraft] Inverted L for 160 meters

[kevinr]

I have to be very careful of raised wires on my property.  If they are 
not above the height of an elk's antlers I am in trouble.  I plan to 
bury them.  This is something I've never done before which has its own 
merit.  I have plenty of wire scrap from broken antennas so the 
non-resonant, buried radials work better for my circumstances.  I need 
to calculate the feed point impedance to see if I need to design a balun 
for the system to work.  Once my main project is done I'll have more 
time for modeling each method.

    Thanks for all the ideas guys,

        73,  Kevin.  KD5ONS


On 8/25/20 5:23 PM, Wes wrote:
> You probably should get acquainted with Rudy Severns, N6LF. 
> (https://www.antennasbyn6lf.com/)  He has written more than you ever 
> want to know about vertical antennas,
>
> More specifically to your case, are you planning the radials to be 
> elevated?  If so, they need to be the same length, in fact some effort 
> should be made to get all of the currents the same.  The last thing 
> you want is a fifty ohm feedpoint impedance with a shortened vertical 
> (which is what an L is).  There is evidence that elevated radials are 
> an improvement over on-the-ground or buried radials.  Mine are on the 
> ground, mainly because 1) I didn't want to give up radiator height to 
> raise the radials, 2) all of the big guns bury theirs and I don't have 
> room for full length radials anyway in my cactus patch.  See my QRZ 
> page for evidence.
>
> My modeling shows a little bit of directivity away from the horizontal 
> wire, but it's negligible.
>
> Wes  N7WS
>
> On 8/25/2020 4:23 PM, kevinr wrote:
>> From what I can find, and what I can calculate, five wires, each ~130 
>> feet long, could make a nice inverted L for 160 meters.  One leg for 
>> the vertical and horizontal portion of the antenna.  Four legs for 
>> the counterpoise (ground plane).  There are many broken wire antennas 
>> stored in my shed which are fodder for the radials. Do all of the 
>> legs for the counterpoise need to be 1/4 wavelength or can I 
>> substitute some shorter lengths?  The feedpoint should somewhere 
>> above 50 ohms impedance.  As I add more radials that number will 
>> reach 50 ohms asymptotically.
>>
>> I can get the vertical part up to 70 or 80 feet above ground with the 
>> rest of it horizontal.  Most of the radiation should take place from 
>> the vertical part since it is closer to the feed point.  But there 
>> should be some effect from the direction of the horizontal portion.  
>> How strongly does the direction of the horizontal portion effect the 
>> radiation pattern of the antenna system?  My property allows me to 
>> point it from 300 degrees around to 200 degrees so I have plenty of 
>> options.  Between 200 and 300 degrees there is a road used by 
>> loggers, and the folks maintaining the towers at the top of this 
>> mountain.  They can break any antenna lower than 80 feet above 
>> ground.  Spar poles and cranes clear out any dead limbs across the road.
>>
>> Inquiring minds...
>>
>> Kevin.  KD5ONS
>>
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