Topband: Modeling the proverbial "vertical on a beach"

[Yuri Blanarovich]

One pony needs to get into one drag radio car and drive around the ocean 
front, over the bridges, back over the land and watch the S-meter and 
listen to the bands. Observant would see 10 - 20 dB difference in signal 
levels in "lousy" mobile, especially on low angle propagation.

Examples: Driving around Sydney, NS and listening to Disney 1670 AM in 
NJ - no signals over land, full quieting solid signal while driving on 
bridge over salt water.
While contesting as N2EE from Cape Hatteras, NC on 10m in contest, was 
told by ZS6EZ to be the first NA he heard, with vertical on the beach.
Results of "Team Vertical" speak for themselves.
Some of us do know. The reverse beacons testing can verify or legitimize 
modeling program's "calculated guessing".

Yuri, K3BU.us


 
 On Sun, Aug 10, 2014 at 11:02 PM, Tom W8JI wrote:
 
 > 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" To: "Tom W8JI" ; 
> "TopBand List" 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" To: "TopBand List" 
>> 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" To: "Guy Olinger 
>>> K2AV" ; "Richard Fry"
>>> Cc: "TopBand List" 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" To: "Richard 
>>>> Fry" Cc: "TopBand List" 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  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
>>>>>>
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