Topband: Modeling the proverbial "vertical on a beach"

Sun Aug 10 23:02:40 EDT 2014

My point is if no one else is on, we really don't how other signals would 
be. It's like a drag race with just one car, or a pony show with one horse.

----- Original Message ----- 
From: "Hardy Landskov" <n7rt at cox.net>
To: "Tom W8JI" <w8ji at w8ji.com>; "TopBand List" <topband at contesting.com>
Sent: Sunday, August 10, 2014 9:08 PM
Subject: Re: Topband: Modeling the proverbial "vertical on a beach"

> Tom,
> I was totallly not expecting any station from that direction, just thought 
> I'd work a few locals with high incident angles before Sunset here. Then I 
> heard the 6Y2 guys and it was amazing. He was the only station--no KV4FZ, 
> NP4A, etc and certainly no EU at our time. Made me a believer in beach 
> verticals.
> 73 N7RT
>
> ----- Original Message ----- 
> From: "Tom W8JI" <w8ji at w8ji.com>
> To: "TopBand List" <topband at contesting.com>
> Sent: Sunday, August 10, 2014 5:20 PM
> Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
>
>
>> How was his signal compared to someone from a similar heading and 
>> distance at the same time who was not on the beach?
>>
>>
>> ----- Original Message ----- 
>> From: "Hardy Landskov" <n7rt at cox.net>
>> To: "Guy Olinger K2AV" <k2av.guy at gmail.com>; "Richard Fry" 
>> <rfry at adams.net>
>> Cc: "TopBand List" <topband at contesting.com>
>> Sent: Sunday, August 10, 2014 7:35 PM
>> Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
>>
>>
>>> Just an observation to all:
>>> When Tom, N6BT went to Jaimaca and operated 6Y2J (I think was the call) 
>>> with verticals on the beach I was blown away. I heard them 2 hours 
>>> before Sunset here on 160....nuff said. The proof is in the pudding.
>>> 73 N7RT
>>>
>>> ----- Original Message ----- 
>>> From: "Guy Olinger K2AV" <k2av.guy at gmail.com>
>>> To: "Richard Fry" <rfry at adams.net>
>>> Cc: "TopBand List" <topband at contesting.com>
>>> Sent: Saturday, August 09, 2014 8:35 PM
>>> Subject: Re: Topband: Modeling the proverbial "vertical on a beach"
>>>
>>>
>>>> Just to mention that the prior opinion is controversial and not 
>>>> universally
>>>> agreed upon. Nor to date has anyone surfaced with actual measurements 
>>>> made
>>>> at the distances (25 to 50 km) and with span of altitudes (0 to 10 km) 
>>>> to
>>>> either prove or disprove either side.
>>>>
>>>> It remains unproven modelling from NEC at those distances either way. 
>>>> This
>>>> situation may, alas, persist this way, because the precise subject
>>>> resolution appears to be without benefit to any commercial interest and
>>>> therefore without funds to pay for some pretty expensive experimenting
>>>> involving precision measurements from aircraft.
>>>>
>>>> Additionally, there is considerable suspicion that moving from LF to MF 
>>>> in
>>>> this general subject involves a ground modal change of some sort that 
>>>> would
>>>> render 50x10 km measurments at 0.5 or 1 MHz unlike those at 2 MHz,
>>>> rendering commercial measurements at low and possibly high BC of no 
>>>> value
>>>> for extrapolation to ham use.
>>>>
>>>> Arguments on both sides remain basically intuitive. I have "reasonable"
>>>> arguments to BOTH concur with Richard AND to not. NEC near field
>>>> calculations over sea water at 50 km follow Richard's assertions, and 
>>>> the
>>>> same over "average" ground does not. The model clearly thinks that 50 
>>>> km
>>>> over most types of ground slowly dissipates low angles resulting in the
>>>> controversial "notch" in low angle elevation patterns.
>>>>
>>>> So NEC based modelling cannot be used as a proof text to decide an 
>>>> argument
>>>> NEC has with itself.
>>>>
>>>> 73, Guy K2AV.
>>>>
>>>>
>>>> On Sat, Aug 9, 2014 at 7:23 PM, Richard Fry <rfry at adams.net> wrote:
>>>>
>>>>> Just to note that the low-angle radiation produced by monopoles is not
>>>>> accurately shown by a NEC model/study that does not include the 
>>>>> surface
>>>>> wave, regardless of whether one or two ground-plane media are 
>>>>> specified in
>>>>> the model.
>>>>>
>>>>> Below is a link to a NEC study of the low-angle fields of a monopole
>>>>> __including the surface wave__ for three values of earth conductivity
>>>>> ranging from extremely good to very poor.
>>>>>
>>>>> The curves there all show maximum relative field in the horizontal 
>>>>> plane.
>>>>>
>>>>> If the surface wave had not been included in these studies then all of
>>>>> those fields would have a zero value in the horizontal plane, and 
>>>>> reduced
>>>>> fields at low angles just above the horizontal plane.
>>>>>
>>>>> Reality is that radiation leaving the monopole at elevation angles of 
>>>>> at
>>>>> least 5 degrees decays at a 1/r rate.  Therefore that radiation is a 
>>>>> space
>>>>> wave which propagates in a ~ straight line to reach the ionosphere, 
>>>>> where
>>>>> (with suitable conditions) it can return to the earth as a skywave.
>>>>>
>>>>> NEC analyses of a vertical monopole of 5/8-lambda and less, and not
>>>>> including the fields of the NEC surface wave do not recognize the 
>>>>> radiation
>>>>> sector capable of producing the greatest single-hop skywave service 
>>>>> range
>>>>> that can be provided by that monopole.
>>>>>
>>>>> http://s20.postimg.org/9xqgzu9d9/Monopole_Low_Angle_Radiation.jpg
>>>>>
>>>>> R. Fry
>>>>> _________________
>>>>> Topband Reflector Archives - http://www.contesting.com/_topband
>>>>>
>>>> _________________
>>>> Topband Reflector Archives - http://www.contesting.com/_topband
>>>>
>>>
>>>
>>> _________________
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