[TowerTalk] Delta Loop Info and Opinions?

[Joe Giacobello]

I have just read the section in Low Band DXing on delta loops and was 
giving consideration to putting up concentric loops for 30 and 40M and 
hanging them by one of the apices from my 70 foot tower.  Although I 
plan on modeling the setup and reading W4RNL's write-ups also, I do have 
several questions and would appreciate hearing from those of you who 
have practical experience with these antennas.

    * I presume that, as with quads, there should be no problem in using
      concentric delta loops?
    * ON4UN in his book recommends detuning the tower by running a wire
      down the side in series with a variable capacitor and tuning for
      minimum current with an RF current probe.  However, it seems that
      this would only work for one of the bands, and you'd have to
      accept some interaction with the tower on at least one of the bands.
    * Does anyone have any experience with this detuning trick?  Did you
      find that it was really necessary? 
    * Do you have any suggestions for how to accomplish detuning for two
      bands?  Two wires and two capacitors? 
    * Does a crankup tower alter this detuning requirement in any way?

I'd appreciate any info you folks out there can provide.

73, Joe
K2XX