[TowerTalk] 10 throu 20 beam traps or no traps

[Herbert Schoenbohm]

Perhaps your right Joe....but tri-band quads deserve better 
consideration as I think they are getting a bad rap.  Below in bold 
italics is my rejoinder.

On 6/20/2014 9:13 AM, Joe Subich, W4TV wrote:
>
>> Why not many serious DX-ers and contesters consider Tri-band or even
>> Five-band quads is a mystery to me.
>
> 1) survivability - quads are much more fragile than yagis with regard
> to icing./*(Certainly not a problem here in the tropics*//*)*/
>
> 2) survivability - wire flexing tends to cause premature failure in
> windy environments /*(Good wire less problem and in 75 MPH winds no 
> breakage yet after 3 years with stranded #14 high quality.)*/
> 3) difficult to handle - a flexible three dimensional structure is
> difficult to get on to a tower, particularly a guyed tower. /*(With a 
> two wire 45 degree boom tram and leaving the center element out it is 
> very easy keeping the wire away from the guys while erecting the 
> antenna.  I string the center element(s) on the tower by spinning the 
> inside hub and using precut wire.)*/
> 4) poor performer - the structural/survivability problems make very
> long boom quads particularly problematic rendering quads uncompetitive
> against very long boom yagis. /*(A three element quad with fiberglass 
> spreaders withstand impact and wind gusting that crack off aluminum 
> elements and if ever broken very easy to repair with a splint and some 
> FG repair compound.) Performance of a three element quad on a 20' boom 
> is equal or better than a 4 element mono bander*//*on even an optimum 
> boom.*//*Plus it has better band coverage which is a real concern for 
> some amps that just trip out at 2:1 VSWR.
> */
>   The added dimension also makes it difficult to stack quads. /*(Who 
> would ever want to?*//*)*//*Again super monster beams and stack are in 
> a totally different category. i thought we were looking for a good 
> subsitute for trap antennas and the problems they present and the lack 
> of performance they are stuck with?)
> *//**/
> All that aside, a two or three element quad can be an effective 
> alternative to a basic trapped tribander if the user has an unguyed
> tower and lives in a benign environment (most don't <G>).
>
> 73,
>
>    ... Joe, W4TV

/*Please also consider the lower Q Quad with less static build up with 
passing TS or even snow static that occurs just when that new country is 
peaking.  Where the quad hears what the yagi doesn't. Some claim that 
like all loops the random noise is less.  This seems to be the case here 
but admittedly could be wishful thinking. I must admit that my low 
quality mast cracked and the quad fell as far as the top guys during a 
wind storm. (I was using fencing for the mast...my bad.) Yet the wires 
snared the quad and after the first calm day the quad was taken apart on 
the tower and reassemble on the ground with new wire. This time I used 
insulated wire and the quad immediately stopped working well.  (I never 
took in consideration the Velocity Factor of the two different wires.) 
Also many aluminum beams that would take such a hit may be be toast with 
a bunch of bent aluminum tubing.*//*


Herb, KV4FZ
*/
> /**/
>
> On 2014-06-20 8:17 AM, Herbert Schoenbohm wrote:
>> Three bands no traps and great performance the three element Cubex Quad
>> wins hands down especially for price and wind load.  Plus with proper
>> matching 75 ohm stubs on 10 and 15 I get both CW and SSB coverage below
>> 1.5 to 1 over the range. Why not many serious DX-ers and contesters
>> consider Tri-band or even Five-band quads is a mystery to me.
>>
>> Herb Schoenbohm, KV4FZ
>>
>>
>>