Topband: Alpha Delta sloper (DX B)

Herb Schoenbohm herbs at
Sat Nov 19 15:09:54 PST 2011

On a 70' tower with lots of toploading Ii just don't know why you don't 
just shunt feed the tower and have a higher performance TX antenna.  
Even connecting a slant wire near the top and feeding it at the bottom
is IMHO a much better compromise.  In fact several broadcast consultants 
noticed the slight directivity of the slant side and petitioned the FCC 
to allow AM stations to use this in lieu of a two tower array to give 
protection on the reverse side that was require by other stations on the 
frequency.  A slant wire feed is not much discussed as a means of 
conveniently feeding a tower but it does perform most likely better than 
an Alpha Delta which requires a coax feed and ground near the tower 
top.  The slant wire allows for fine tuning at the ground connection 
feed point.  Also if you want to make it work on 160 and 80 a single 
W2AU 80 meter trap at the appropriate spot up the slant will work. It 
should also create a slight amount of directivity  with the tower acting 
as an aperiodic reflector of sorts.  The difference in performance could 
be modeled by one of the modeling specialists on this reflector.  I am 
almost certain the slant wire feed to a 70' top loaded tower would 
really be a better antenna for you on 160 meters.

Herb, KV4FZ

On 11/19/2011 4:38 PM, navydude1962 at wrote:
> To amplify. This will go up on a 70' tower with lots if top loading.   AD recommends putting it at the top of the tower.
> Sent from my iPhone
> On Nov 19, 2011, at 12:14, "Mike&  Coreen Smith"<ve9aa at>  wrote:
>> ED,
>> I had up an Alpha-Delta DX-A Twin sloper...I think it was the A model not the B model.
>> It was on a 48' tower only  at the 26' mark.  Some big 6m beams up on the top.
>> It worked "OK" but not great....had it on 3  different towers usually around the 30'(ish) mark.
>> Before I owned it, another ham had it up @ the 48' mark and again...."meh".....not the greatest
>> but certainly better than a low dipole.  IE: Your tower provides the other half of the antenna.
>> VE9AA
>> Mike, Coreen&  Corey Smith
>> 699 Rte 616 Keswick Ridge
>> NB
>> Canada
>> E6L 1T1
>> ----- Original Message -----
>> From: navydude1962 at
>> To: w0rihps at
>> Cc: ZR ;<topband at>  ; Bruce
>> Sent: Saturday, November 19, 2011 1:42    PM
>> Subject: Topband: Alpha Delta sloper (DX B)
>> Has anybody tried one of these on 160m?  Thoughts appreciated.
>> 73
>> Ed NI6S

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