Towertalk
[Top] [All Lists]

Re: [TowerTalk] EZNEC- needs improvement

To: towertalk@contesting.com
Subject: Re: [TowerTalk] EZNEC- needs improvement
From: Steve Hunt <steve@karinya.net>
Date: Sun, 05 Apr 2009 22:54:25 +0100
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Paul,

I'm not quite sure what point you are making.

The dipole doesn't just "cut off" below some angle. Let's suppose the 
vertical had a 10db advantage over the dipole at 6 degrees, and the 
dipole beat the vertical by 10dB at 23 degrees. If your point is that 
the signal strength on the 6 degrees path is very much stronger (say by 
20dB) than that on the 23 degree path, the vertical will still only show 
a 10dB advantage because the 6 degree path is dominant for both antennas.

Or have I misunderstood what you are saying?

Steve G3TXQ

Paul Playford wrote:
> Just for yucks, bring up W6ELprop and:
>
> insert 23 degrees as your Minimum Radiation Angle (Options - Prediction 
> Parameters).
> Then run a prediction to a country maybe 10000 Km away.
> Look at the predicted signal levels and scroll to the time that the best 
> signal level will occur on your chosen band.
> Click on Advanced and scroll to the same time and note the Hop 
> Configuration.
>
> Now insert 1.5 degrees as your Minimum Radiation Angle
> run the prediction again
> scroll to the same time
> observe the Hop Configuration
>
> And take a guess at how much signal you lose for each additional hop the 23 
> degree path takes as compared to the 6 degree path.  That will give you an 
> idea of the differences you are observing and cannot be inserted into EZNEC.
>
> de Paul, W8AEF
>
> ZF2JI/ZF2TA  FO8DX/FO8PLA  8Q7AA  XZ0A  VU7RG  TX5C
>
>
>
> ----- Original Message ----- 
> From: "Steve Hunt" <steve@karinya.net>
> To: <towertalk@contesting.com>
> Sent: Sunday, April 05, 2009 1:02 PM
> Subject: Re: [TowerTalk] EZNEC- needs improvement
>
>
>   
>> Dick,
>>
>> It seems to me that EZNEC would confirm your own experience. If I model
>> a 40m dipole at 90ft over salt water compared to a 1/4 wave vertical at
>> ground level, EZNEC has the vertical better at low angles, by as much as
>> 10dB. I realise the XM-240 should do better than the dipole I modelled,
>> but not by more that 3 or 4 dB I would have thought.
>>
>> Steve G3TXQ
>>
>>     
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>   

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>