TopBand: Re: EWE Info

[km1h @ juno.com]

On Mon, 27 Oct 1997 14:04:45 EST k6se@juno.com (Earl W Cunningham)
writes:
>On Mon, 27 Oct 1997 08:21:09 EST km1h@juno.com (km1h @ juno.com) 
>writes:
>
>>Earl and the group:
>>
>>I have in front of me a  EWE design that was sent to me by Floyd, 
>>WA2WVL, a few years ago. It may be of interest inasmuch as the values 
>
>>differ considerably from Earl's. 
>>
>>For "good soil" 5mm/meter:
>>
>>Length	 50' 
>>Resistor 	1285 Ohms
>>Height	 10'
>>Wire 	#12
>>Frequency	 1825kHz
>>Inductance 	37uh to tune out reactance at feedpoint
>>Feed Z	396 Ohms +j7
>>Elevation Peak 	23 deg
>>
>>My point here is that there appears to be a lot of discrepancy 
>between 
>>antenna programs. Floyd uses K6STI's AO and this particular run 
>>compares well against NEC-Wires. 
>================================
>WA2WVL's design is quite appropriate for the "inverted-U" style of Ewe 
>(two 10' supports), although I disagree with "396 + j7" -- the 
>positive reactance is obviously an error. 

Why would you consider it an error? The reactance compensating inductor
is not perfect of course but I fail to see where a j+7 is any big deal.
This just happens to be the result without taking the L value to
ridiculous levels of accuracy. In other words...it is repeatable without
a lab. 


 The elevation peak" is also 
>too low -- 32 deg is closer for a single Ewe (of either variety) over 
>"good" soil.
>
>The parameters for my version, or "inverted-V" (one 10' support) 
>design do indeed differ, but it's a different Ewe.

At 160M I fail to see how a few feet in elevation or slope can make a
difference when the bloody wire is only 30-50' long. 


>
>Like Carl, I'm also interested in others' modeling results with 
>different software versions.  I feel that EZNEC or NEC-Wires (both 
>NEC2-based) would be most appropriate for designing wire antennas with 
>bends in the wires (such as any variety of the Ewe), although ELNEC or 
>AO (both MININEC-based) should also yield good results.
>
>73, de Earl, K6SE


As with Earl, I am not looking for arguments here. I just have a hard
time understanding the huge discrepancies amongst programs.
My own goal is to maximize my RX setup....and understand what is
happening with it. 
Thanks also to Tom, W8JI, for insights and comments.

73   Carl   KM1H

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