[Antennas] DCTL questions

[fkamp at comcast.net]

Hue Miller wrote:
> 
> The DCTL antenna - it's really a half-wave loop, right? But with continuous
> capacitive loading between the two identical loops, it is shortened to about
> 1/8 wave total loop length (  with about 1/4w worth of wire, total. )
> 
> I read an article by someone who built 2, one using twinlead, the other using
> ladder line. But unhelpfully, the article does not say another word about
> comparison of the two. This article is posted on the net. I wrote the author
> to say that if his conclusions were negative, he should title his article "Do
> Not Build this Antenna", instead of describing how-to.
> 
> Anyway, my questions: Since the antenna depends on continuous
> capacitive loading, it would be best to use twinlead instead of ladder
> line, right? Also, the 2 stubs: the tuning stub could be replaced by
> a high voltage variable cap, right? And the shorting stub, probably
> with a coil transformer for impedance matching?
> -Hue Miller


Monty, N5ESE, has a writeup about his experiences with the DCTL on his
webpage at

http://www.io.com/~n5fc/dctl_ant.htm

I believe he was using it indoors and claimed a 1 to 1.5 S-unit
difference between it and an outdoor dipole.

As I recall, an S-unit is about 6db.  That is a pretty significant
reduction.  Maybe an unfair comparison since the dipole was outside and
the DCTL was indoors.  

My experience has been that half-sized antennas result in half-sized
performance.  I suppose an indoor DCTL might be better than an indoor
quarter wave, base loaded whip, but I would put my money on full
wavelength loop located outside.

Regards,
Frank Kamp
K5DKZ