I believe the K6STI loop and even
the Flag/Pennant family are getting unfairly slammed in the
informal ham 'press' such as the Topband group. While the
temptation to compare them is absolutely irresistable, it is
simply unfair to compare them with Beverages. The latter
type need a lot more room- at least a couple hundred linear
feet, and really more like 500 feet plus- they are simply
in a class by themselves. I think the problem is that hams
seem to forget the former types are *low output* antennas.
It is certainly not fair to declare that the antennas did not work
or were deaf without trying them on their own terms, and that
means having a good preamp capable of variable gain setting
of around 10 to 30dB with acceptable intermod performance
(which eliminates a good percentage of the preamps in use
today). Also, in the case of the omnidirectional K6STI, a good
high pass or bandpass filter if there are any nearby loud AM
broadcasters below 1700KHz.
FWIW, I have been very lazy here in not yet getting around to
building a preamp yet. I will do so shortly, using 2N5109 CATV
transistors. There are two good designs floating around, by
W7IUV and W8JI, that will give excellent performance on top
band in the presence of big pileups (low intermod).
Even so, and not having the benefit of any preamp, I have been
able to easily see that the various low noise receive-only
antennas such as the Ewe, K9AY, Flag, Pennant, K6STI, other
low, medium/large horizontal loops and even my shorty 225 ft
Beverage all have merit and all are worth building
and experimenting with.
It very much discourages me when I read negative reports on
these antennas where the builder did not allow enough time
(weeks or months) to see how the antenna really works, or where
the builder is dismissing the antenna after trying it with no preamp
or with modifications that may hurt the performance. All I can say
is- of course they are not going to hear as well as a full size
Beverage! Sometimes even a 250-300ft Beverage will beat them.
But not all hams have room for Beverages. Is it fair to the small
lot owners to falsely convince them that these various receiving
antennas are not even worth trying? I say No! Every antenna I
have mentioned above has been written up in the literature and
used successfully to obtain real, measureable improvement in
weak-signal DX S/N over a large transmitting antenna, especially
verticals (which includes most low band Tx antennas, even loops,
vees, etc.) Please consider that (1.) we need all the new ops we
can get on the low bands, in order to keep up interest and activity
levels, and (2.) most hams are small lot owners and do not have
room for Beverages! Let us be lavish in our praise when we come
across good results, and sparing in our criticism when we get
results that disappoint. I don't think even one of the antenna
types mentioned here are 'snake oil'- all are proven performers
in my book, based on personal experience and the results of
others. Remember- not all athletes are olympians, but that does
not mean they are bad athletes. Likewise, not all receive
antennas are Beverages, but that does not mean they are
useless or bad designs. :o) 73, David K3KY
|