[Elecraft] Inverted L for 160 meters

[Walter Underwood]

ON4UN's Low Band DXing book is on sale for $20 right now. Get that and you’ll know as much as anybody about radials.

https://www.arrl.org/shop/ON4UN-s-Low-Band-DXing <https://www.arrl.org/shop/ON4UN-s-Low-Band-DXing>

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Aug 25, 2020, at 8:14 PM, David Gilbert <ab7echo at gmail.com> wrote:
> 
> 
> If you are going to go with buried radials, I don't think 4 or 5 of them is going to do a very good job for you.
> 
> Like N7WS recommended, look up N6LF's work and read it carefully. Seriously.
> 
> 73,
> Dave   AB7E
> 
> 
> 
> 
> On 8/25/2020 5:31 PM, kevinr wrote:
>> 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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