I don't know. I'll take my elevated 40/30M vertical at 30' with 8 radials
over any ground mounted vertical with 60+ radials. Been there done that. Huge
difference.
73,
Jim N9WW
James Chaggaris
President
PowerOne Corp.
2325 Dean St. Suite 800J
St. Charles, IL 60175
Phone: (630)443-6500
> On Mar 15, 2021, at 7:55 PM, Ignacy Misztal <no9e@arrl.net> wrote:
> N6LF study was in OR (?) with good soil and on 40m. W8JI found by
> measurements that elevated radials (in GA) on 160m work a few db below the
> ground radials. His results as well as experiences of other hams are in the
> ON4UN book. GA clay soil has perhaps average conductivity and 160m is not
> 40m.
>
> WSPR is good for testing but is very slow. RBN is much faster. I call CQ on
> one frequency, change antenna and call 2 kHz up. Then look at spots on RBN
> and average Fun work.
>
> Radials (or counterpoises) can be any size. See Cushcraft R7. With an
> electrical quarter wave their impedance is low and the vertical ca be fed
> directly. When radials are shorter, the feed point is "hot", the coax
> becomes a lossy radial, and all baluns except the massive one overheat. But
> with a transformer like advocated by K2AV, no heating. FT140-61 with
> "Ethernet" wire is good for 500W.
>
> One elevated radial is sufficient on the beach. I operated Stew Perry
> contest from a beach in St George FL with inv L to a 50' tree and one
> elevated radial 4 f high. EU was loud 2 hrs before the sunset, and 100W
> signals louder to EU than from KW stations inland.
>
> Ignacy NO9E
>
> On Mon, Mar 15, 2021 at 5:44 PM Jeff Blaine <KeepWalking188@ac0c.com> wrote:
>
>> Further to Grant's comment, the N6LF info is available, free, at the
>> N6LF web site.
>>
>> That series of QEX articles really should be the first stop for guys
>> wondering about their ground system effectiveness.
>>
>> 73/jeff/ac0c
>> alpha-charlie-zero-charlie
>> www.ac0c.com
>>
>>
>> On 3/15/21 4:34 PM, Grant Saviers wrote:
>>> N6LF has several plots of the change in gain for elevated radials
>>> shorter than 1/4wl. For elevated, about 15% shorter then 1/4wl is the
>>> peak IIRC. WA3FET did calculations of best # & length for a given
>>> total length of radial wire on the ground. YMMV.
>>> Grant KZ1W
>>> On 3/15/2021 12:52, N4ZR wrote:
>>>> This is the second allusion to 1/8 wave elevated radials that I've
>>>> read, but I've been unable to find anything further, in the usual
>>>> sources. Any leads? I have an inverted L, but really don't have room
>>>> for 1/4 wave elevated radials and am told that my 8 x 70 foot radials
>>>> on the ground really aren't worth much.
>>>> 73, Pete N4ZR
>>>> Check out the new Reverse Beacon Network
>>>> web server at <http://beta.reversebeacon.net>.
>>>> For spots, please use your favorite
>>>> "retail" DX cluster.
>>>> On 3/15/2021 3:00 PM, Ignacy Misztal wrote:
>>>>> My feeling is that modeling with verticals is less than perfect or
>>>>> perhaps
>>>>> the interpretation of results from modeling is imperfect.
>>>>> In 160m contests we hear signals that are poor, OK and spectacular. In
>>>>> cases I know, those OK have 30 radials and those spectacular have 100
>>>>> radials. While the maximum angle radiation may be affected by < 1 db,
>>>>> perhaps low angle radiation may be affected by 10db or more.
>>>>> I had an inverted L with up 80 feet with 4 elevated and tuned
>>>>> radials. Then
>>>>> a shunt fed a 100ft tower with 16 upgraded later to 36 radials.
>>>>> Modeling
>>>>> indicated little difference. When tested by RBN, the tower was 6 db
>>>>> better
>>>>> with 16 radials and 8 db better with 36. Well worth the effort.
>>>>> I used to have an inv L with a few 70 ft elevated radials used for both
>>>>> 160m and 80m. The performance was OK on 160m and pathetic on 80m.
>>>>> There are
>>>>> papers showing that 4 1/8 wave radials on the ground are better than
>>>>> 4 1/4
>>>>> wave radials. Perhaps this applies to low elevated radials.
>>>>> Verticals with
>>>>> short radials need a transformer, not a balun.
>>>>> Ignacy NO9E
>>>>> On Mon, Mar 15, 2021 at 11:58 AM Patrick Greenlee
>>>>> <patrick_g@windstream.net>
>>>>> wrote:
>>>>>> What comes to mind is how true to reality is the model's results? If
>>>>>> the model is relatively true to reality then most of us would
>>>>>> likely not
>>>>>> bother with additional radials.
>>>>>> You said, "It is working great." Is that a reasonable motivation
>>>>>> to add
>>>>>> 4 more radials to maybe get 0.01 more dBi? The term diminishing
>>>>>> returns
>>>>>> comes to mind.
>>>>>> I would suggest leaving it alone and enjoy using it.
>>>>>> Have fun.
>>>>>> Patrick NJ5G
>>>>>> .
>>>>>> ------ Original Message ------
>>>>>> From: "Dave Sublette" <k4to.dave@gmail.com>
>>>>>> To: "kj6y--- via TowerTalk" <towertalk@contesting.com>
>>>>>> Sent: 3/15/2021 10:26:00 AM
>>>>>> Subject: [TowerTalk] Vertical question
>>>>>>> Good morning,
>>>>>>> I recently changed my elevated 160 meter quarter wave vertical
>>>>>>> with 8 full
>>>>>>> sized radials to having only 1/8th wave length radials and only
>>>>>>> four of
>>>>>>> them. It is working great. So I thought adding four more radials
>>>>>>> might
>>>>>>> improve things.
>>>>>>> But before I went to all the trouble I decided to model it and see if
>>>>>> there
>>>>>>> was a difference in performance of the 8 radial version compared
>>>>>>> to the 4
>>>>>>> radial system.
>>>>>>> I use a modelling program called Antenna Model. The result of the
>>>>>>> comparison is this:
>>>>>>> The 4 radial system showed a gain of 0.92 dBi with the main lobe
>>>>>>> at an
>>>>>>> elevation of 20 degrees.
>>>>>>> The 8 radial system showed a gain of 0.93 dBi and an identical
>>>>>>> elevation
>>>>>>> pattern.
>>>>>>> My question is: Why is the gain figure so low? A dipole exhibits
>>>>>>> 2.14
>>>>>> dBi
>>>>>>> gain. Why doesn't the vertical show gain?
>>>>>>> And lastly, I think these results tell me it isn't worth the
>>>>>>> effort to add
>>>>>>> four more radials.
>>>>>>> Your thoughts?
>>>>>>> Thanks & 73,
>>>>>>> Dave, K4TO
>>>>>>> _______________________________________________
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