[TowerTalk] add a 3rd el to 40-2cd

[Joe Subich, W4TV]

On 3/13/2018 1:19 PM, Jim Brown wrote:
 > I agree with all of Bob's post, taking into account that he's talking
 > about 40M. Steve may have been thinking of higher bands, for which his
 > advice is quite good.

Jim is correct here ... 72' is a half wave on 40 meters.  Stacking a
second antenna at half that height would put the lower antenna at *one*
*quarter wave* above ground.  The lower antenna would have its maximum
lobe nearly straight up - exactly where the top antenna has its null.

The stacked pair, with 1/4 wave spacing, will have significant mutual
coupling (pattern distortion and SWR issues) and will show little if
any gain from stacking.  Now, if one were talking about 140' and 70'
(or even 120' and 60') that would be a whole different ballgame.

73,

    ... Joe, W4TV


On 3/13/2018 1:19 PM, Jim Brown wrote:
> On 3/13/2018 10:12 AM, Bob Shohet, KQ2M wrote:
>> I respectfully have to disagree with Steve on this.
>>
>> Stacking with a lower antenna is highly unlikely to produce a lower 
>> wave angle.
> 
> I agree with all of Bob's post, taking into account that he's talking 
> about 40M. Steve may have been thinking of higher bands, for which his 
> advice is quite good. It would also be good for 40M if the QTH had the 
> terrain advantage of a mountaintop or even a pronounced knoll.
> 
> 73, Jim K9YC
> 
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